Article

Risk Compensation Is Not Associated with Male Circumcision in Kisumu, Kenya: A Multi-Faceted Assessment of Men Enrolled in a Randomized Controlled Trial

School of Public Health, University of Illinois at Chicago, Chicago, Illinois, United States of America.
PLoS ONE (Impact Factor: 3.23). 06/2008; 3(6):e2443. DOI: 10.1371/journal.pone.0002443
Source: PubMed

ABSTRACT

Three randomized controlled trials (RCTs) have confirmed that male circumcision (MC) significantly reduces acquisition of HIV-1 infection among men. The objective of this study was to perform a comprehensive, prospective evaluation of risk compensation, comparing circumcised versus uncircumcised controls in a sample of RCT participants.
Between March 2004 and September 2005, we systematically recruited men enrolled in a RCT of MC in Kenya. Detailed sexual histories were taken using a modified Timeline Followback approach at baseline, 6, and 12 months. Participants provided permission to obtain circumcision status and laboratory results from the RCT. We evaluated circumcised and uncircumcised men's sexual behavior using an 18-item risk propensity score and acquisition of incident infections of gonorrhea, chlamydia, and trichomoniasis. Of 1780 eligible RCT participants, 1319 enrolled (response rate = 74%). At the baseline RCT visit, men who enrolled in the sub-study reported the same sexual behaviors as men who did not. We found a significant reduction in sexual risk behavior among both circumcised and uncircumcised men from baseline to 6 (p<0.01) and 12 (p = 0.05) months post-enrollment. Longitudinal analyses indicated no statistically significant differences between sexual risk propensity scores or in incident infections of gonorrhea, chlamydia, and trichomoniasis between circumcised and uncircumcised men. These results are based on the most comprehensive analysis of risk compensation yet done.
In the context of a RCT, circumcision did not result in increased HIV risk behavior. Continued monitoring and evaluation of risk compensation associated with circumcision is needed as evidence supporting its' efficacy is disseminated and MC is widely promoted for HIV prevention.

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Risk Compensation Is Not Associated with Male
Circumcision in Kisumu, Kenya: A Multi-
Faceted Assessment of Men Enrolled in a Randomized
Controlled Trial
Christine L. Mattson
1
*, Richard T. Campbell
1
, Robert C. Bailey
1
, Kawango Agot
2
, J. O. Ndinya-Achola
3
,
Stephen Moses
4
1 School of Public Health, University of Illinois at Chicago, Chicago, Illinois, United States of America, 2 UNIM Project, Kisumu, Kenya, 3 Department of Medical
Microbiology, University of Nairobi, Nairobi, Kenya, 4 Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada
Abstract
Background:
Three randomized controlled trials (RCTs) have confirmed that male circumcision (MC) significantly reduces
acquisition of HIV-1 infection among men. The objective of this study was to perform a comprehensive, prospective
evaluation of risk compensation, comparing circumcised versus uncircumcised controls in a sample of RCT participants.
Methods and Findings:
Between March 2004 and September 2005, we systematically recruited men enrolled in a RCT of MC
in Kenya. Detailed sexual histories were taken using a modified Timeline Followback approach at baseline, 6, and 12
months. Participants provided permission to obtain circumcision status and laboratory results from the RCT. We evaluated
circumcised and uncircumcised men’s sexual behavior using an 18-item risk propensity score and acquisition of incident
infections of gonorrhea, chlamydia, and trichomoniasis. Of 1780 eligible RCT participants, 1319 enrolled (response
rate = 74%). At the baseline RCT visit, men who enrolled in the sub-study reported the same sexual behaviors as men who
did not. We found a significant reduction in sexual risk behavior among both circumcised and uncircumcised men from
baseline to 6 (p,0.01) and 12 (p = 0.05) months post-enrollment. Longitudinal analyses indicated no statistically significant
differences between sexual risk propensity scores or in incident infections of gonorrhea, chlamydia, and trichomoniasis
between circumcised and uncircumcised men. These results are based on the most comprehensive analysis of risk
compensation yet done.
Conclusion:
In the context of a RCT, circumcision did not result in increased HIV risk behavior. Continued monitoring and
evaluation of risk compensation associated with circumcision is needed as evidence supporting its’ efficacy is disseminated
and MC is widely promoted for HIV prevention.
Citation: Mattson CL, Campbell RT, Bailey RC, Agot K, Ndinya-Achola JO, et al. (2008) Risk Compensation Is Not Associated with Male Circumcision in Kisumu,
Kenya: A Multi-Faceted Assessment of Men Enrolled in a Randomized Controlled Trial. PLoS ONE 3(6): e2443. doi:10.1371/journal.pone.0002443
Editor: Landon Myer, University of Cape Town, South Africa
Received March 8, 2008; Accepted May 1, 2008; Published June 18, 2008
This is an open-access article distributed under the terms of the Creative Commons Public Domain declaration which stipulates that, once placed in the public
domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.
Funding: This research was supported by grant number AI50440 from the Division of AIDS, National Institute of Allergies and Infectious Disease of the United
States National Institutes of Health and by grant number HCT 44180 from the Canadian Institutes of Health Research (CIHR).
Competing Interests: The authors have declared that no competing interests exist.
* E-mail: christine.mattso n@gmail.com
Introduction
The results of three randomized controlled trials (RCTs) have
demonstrated that male circumcision (MC) significantly reduces
acquisition of heterosexually transmitted HIV-1 among men,[1–3]
confirming observational evidence [4,5] and adding plausibility to
previous immunohistochemistry studies of the foreskin. [6,7] All
three trials were stopped prematurely by their respective Data and
Safety Monitoring Boards when, at interim analyses, circumcision
was found to be highly efficacious in reducing HIV incidence,
indicating that it would be unethical to continue withholding
circumcision from the control group. [8–10] The protective effect
of male circumcision ranged from 51% to 60% in intent to treat
analyses, and from 60% to 76% in as treated analyses. Despite
these results, concern about how men perceive the protective effect
of circumcision remains. [11] If circumcised men believe that
circumcision confers substantial or complete protection against
HIV infection, they may engage in increased risk behavior,
commonly referred to as risk compensation or behavioral
disinhibition. [12] Significant risk compensation could reduce
the protective effect of circumcision and possibly result in
increased rather than decreased incidence of HIV.
The empirical evidence regarding risk compensation in the
context of male circumcision is inconsistent. Two cross-sectional
studies have indicated that circumcised men engage in higher risk
behaviors than uncircumcised men; however, given the observa-
tional nature of the studies, these results could reflect confounding.
[13,14] In contrast, a prospective cohort study conducted in Siaya
and Bondo Districts, Kenya found that circumcised men did not
have more extra-marital sex partners than uncircumcised men.
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[15] Data from the RCTs of MC did not show consistent evidence
of risk compensation; however, minimal increases in some risky
behaviors were noted. [1–3] In the Orange Farm study, the
following five variables were evaluated at baseline and at 3, 12,
and 21 months later: at least one sexual contact without a condom,
being married or living as married, more than 1 non-spousal
partner, at least one sexual partnership with only one sexual
contact, and more than 5 sexual contacts. Only differences in
mean number of sexual contacts were statistically significant
between 4–12 months after circumcision (5.9 versus 5.0, p,0.001)
and 13–21 months (7.5 versus 6.4, p = 0.0015). [1] Controlling for
behavioral differences between study groups altered the protective
effect against HIV acquisition minimally from 60% (95% CI
32%–76%) to 61% (95% CI 34%–77%). [1] All other differences
were non-significant.
The Ugandan trial found no consistent evidence of behavioral
disinhibition. [3] In this study, the following sexual behaviors were
evaluated: condom use (defined as none, inconsistent, or
consistent), number of sexual partners (0, 1, 2, 3+), any non-
marital partners, alcohol use with sexual intercourse (none versus
any), and transactional sex (exchanging money or gifts for sex).
There was no difference in the proportion of circumcised and
uncircumcised men reporting consistent condom use at the 6, 12
and 24 month follow-up visit (p = 0.11, p = 0.6, p = 1.0, respec-
tively). Inconsistent condom use was higher in the circumcised
group (p = 0.0004) at the 6 month follow-up visit, but men in the
control group were more likely to report no condom use compared
to circumcised men (p = 0.0004). [3] At the 12 and 24 month
follow-up visits, number of sexual partners, non-marital relation-
ships, and condom use were similar in both groups. Alcohol use
with sexual intercourse was the same at enrollment, but higher
among uncircumcised men at the 6 month (p = 0.001), 12 month
(p = 0.06), and 24 month follow-up visit (p = 0.02). Transactional
sex did not differ between groups.
In the Kenya trial, the following sexual behavior variables were
evaluated: unprotected intercourse with any partner in the
previous 6 months, last sexual relations with a casual partner,
sexual abstinence in the last 6 months, consistent condom use in
the previous 6 months, and 2 or more partners in the previous 6
months. There was a reduction in risk behavior among both
circumcised and uncircumcised men from baseline to follow-up
visits, except in the proportion of men reporting 2 or more sex
partners, which progressively declined in the control group
throughout the duration of follow-up, but declined and then
stabilized after the 6 month follow-up visit in circumcised men. [2]
At the 24 month follow-up visit, the proportion of circumcised
men reporting unprotected sexual intercourse in the previous six
months was greater than the control group (p = 0.03), and fewer
circumcised men reported consistent condom use versus controls
(p = 0.03), which could suggest that men’s behavior became
refractory to prevention messages. [2] It is notable that risk
behaviors declined for both circumcised and uncircumcised men
from baseline to 24 months of follow-up, which the authors
attribute to the risk reduction counseling that participants
received. [2] It was suggested that circumcised men not only did
not increase their sexual risk behaviors after circumcision, they
reduced their risk, but there were even greater reductions from
baseline to month 24 in the control group. [2]
At most, 5 behaviors were evaluated in the context of the trials
and the behaviors chosen to indicate sexual risk varied across
studies. Measuring condom use and sex with multiple partners is
conventional in studies of risk compensation, but how those
variables are defined and what other behaviors are chosen to
represent risk are not consistent. This is due, in part, to the lack of
a consensus definition of ‘‘sexual risk,’’ as well as to the statistical
challenges inherent in analyzing multiple, highly correlated
behavioral variables. [15] It is possible that information obtained
from relatively brief questionnaires lacks sufficient breadth to
comprehensively address the issue of risk compensation. This study
was specifically designed to measure and analyze a comprehensive
set of sexual behaviors by applying a behavioral risk propensity
scale developed to assess risk compensation in circumcised versus
uncircumcised men participating in the circumcision trial in
Kenya.
Methods
Design and Data Collection
The Kenyan RCT of MC enrolled men who were sexually
active within the last 12 months, were HIV negative, uncircum-
cised at baseline, aged 18–24 years, and resident in Kisumu
District. The men received HIV testing and counseling on risk
reduction strategies following Kenyan National Guidelines at the
following RCT visits: 1, 3, 6, and 12 month. All men who enrolled
in the RCT between March 2004 and September 2005 were
systematically invited to participate in the current study, which
took place at a separate facility approximately 100 meters from the
trial study site. The men received HIV testing and counseling on
risk reduction strategies following Kenyan National Guidelines at
the following RCT visits: 1, 3, 6, and 12 month. All men were
informed that although there was some evidence of an association
between circumcision and reduced HIV acquisition, the evidence
was not conclusive. Participants provided written informed
consent to undergo separate interviews for this study at baseline
and at 6 and 12 month follow-up visits, and allowed us to obtain
data from the RCT. The questionnaires and consent documents
were developed in English and translated into Dholuo and
Kiswahili (the predominant local languages) independently by two
indigenous speakers, and discrepancies were resolved with
assistance from a third individual. Interviews were conducted by
male interviewers fluent in all three languages. Men were offered
150 Kenyan shillings (approximately $2.00 USD) for each
scheduled visit to cover transport and loss of income. The research
protocol was approved by the Kenyatta National Hospital Ethics
and Research committee, the University of Illinois at Chicago’s
Institutional Review Board # 3, and the University of Manitoba
Biomedical Research Ethics Board.
To obtain sexual histories, we adapted the well-validated
Timeline Followback approach [16] to collect information about
every sexual relationship in the last 6 months for up to 12 partners
at baseline (within 10 days of being randomized in the trial), and at
6 and 12 month follow up visits (plus or minus 3 months).
Interviewers obtained the following information for each partner:
age, gender, type of partner, dates of the relationship, length of
time knowing the partner prior to sex, approximate number of
sexual encounters, sexual practices (vaginal, oral, anal), exchange
of sex for money or gifts, condom use (ever used a condom with
the partner, used at the first encounter, at last encounter, and at
every encounter), and clients’ perception of their partners (e.g. if
partners had other partners concurrently, engaged in transactional
sex, or were thought to be HIV positive). Men were identified as
having a concurrent partnership if the start and end dates of any
two partners overlapped by at least one month. Men were also
asked whether or not they thought circumcision reduced the risk of
HIV. A priori power analyses indicated that 500 circumcised and
500 uncircumcised men would provide at least 80% power to
detect an absolute difference of 7% among the proportion of men
reporting unprotected sex with 2 or more partners between
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baseline and the 6 or 12 month follow-up visits with a base rate of
.45 (paired proportion) among uncircumcised men with two-sided
type 1 error of 0.05.
Using item response theory [17,18], we developed an 18-item
behavioral risk propensity scale to capture specific behaviors and
practices that men reportedly engaged in with each partner
discussed in their sexual histories (for up to 12 partners). Items
were included in the scale if previous epidemiologic research
demonstrated they were risk factors for HIV [19] and there was
reason to believe the behavior may be affected by circumcision
(e.g. condom use, multiple sex partners, transactional sex, etc).
Count variables were created to summarize behaviors across 0–12
partnerships. Using differential item function analyses, we
demonstrated that the scale performed consistently at all three
time points, and whether interviews were conducted in English or
not (Dholuo or Kiswahili). The resulting logit risk scores were
transformed so that the lowest logit score (24.62) was equal to
zero. Transformed scores ranging from 0 to 9.24 were computed
at baseline, 6 and 12 month follow-up visits. The scale
demonstrated very good reliability (Cronbach’s alpha of 0.87)
and, based on assessments of monotonicity; it resulted in a
unidimensional continuum to represent sexual risk propensity (e.g.
sexual behavior).
The scale’s construct validity (i.e. whether it does, indeed,
measure risky sexual behavior) was established by demonstrating
that men’s scores on the risk scale were associated with the
presence of an incident sexually transmitted infection (STI) of
Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis or
incident HIV (in press). At both follow-up visits men diagnosed with
an incident STI had higher risk scores than uninfected men, but
the difference was only statistically significant at the 6 month
follow-up visit (Wilcoxon two-sided probability p = 0.01), presum-
ably due to the small number of respondents with STIs at the 12
month follow-up visit (n = 24). At the 6 and 12 month follow-up
visits, 8 and 4 men respectively were diagnosed with incident HIV
infection. Similar to the STI analyses, men who seroconverted
throughout the study had higher risk scores than those who did
not. The non-parametric Savage Two-Sample Test with one-sided
probability was borderline at 6 months (p = 0.07) and statistically
significant at 12 months (p = 0.01).
To corroborate self-reported risk behavior, we independently
evaluated incident STIs as a secondary outcome variable. Because
these infections occurred at a relatively high rate in our study
population, [20,21] and are not generally considered to be
associated with male circumcision, they provide ideal biologic
markers of sexual risk behavior. [22,23] Also, since men received
treatment for their infections, it was possible to distinguish
prevalent from incident infections. [24] We used the following
diagnostic criteria to identify infections: Neisseria gonorrhoeae and
Chlamydia trachomatis: by polymerase chain reaction assay (AMPLI-
CORH CT/NG Test, Roche Diagnostics, Montreal Canada) and
Trichomonas vaginalis: by culture (InPouch
TM
TV test, Biomed
Diagnostics, Oregon, United States). Infections identified at
baseline were considered prevalent. Since men identified with an
STI at baseline were treated, infections subsequent to baseline
were considered incident.
Statistical Analyses
Data were entered into SPSS Version 10.0 (SPSS Inc., Chicago,
IL). Approximately 30% of interviews were entered in duplicate to
evaluate accuracy. The error rate was less than 1%. Further data
management, descriptive analyses, and multivariable modeling
were performed in SAS Version 8.2 (SAS Institute Inc., Cary,
North Carolina, USA).
To compare men who enrolled in the sub-study to those who
did not and to compare circumcised to uncircumcised men at
baseline, we used Pearson Chi-Square tests for categorical
variables, independent t-tests for normally distributed continuous
variables and Wilcoxon’s Two Sample Z Test for continuous
variables that were not normally distributed. To evaluate whether
circumcision altered men’s sexual risk behavior, we used random
effects regression models to deal with statistical dependence
resulting from repeated observations. [25]
The primary outcome was the 18-item risk score, which had a
‘‘semi-continuous’’ or ‘‘mixed’’ distribution ranging from 0 to 9.
[26–28] Men who had not engaged in any sexual activity in the
past 6 months had scores of 0, but men who were sexually active in
the 6 months prior to the interview had scores ranging from .0–9.
We implemented a two-part random effects regression model to
accommodate the ‘‘semi-continuous’’ distribution. [27] The first
equation in the model evaluated whether or not men engaged in
any activity in the last 6 months as a binary yes/no outcome
(modeled as logistic) and the second equation modeled the positive
sexual risk score as a continuous outcome (modeled as lognormal
to account for the skewed distribution). The covariates were
interpreted as if the two parts of the model were fit separately but
the random effects in the two equations were allowed to correlate.
Population-averaged rather than subject-specific odds ratios are
reported. [25] The model was estimated using SAS Proc Mixed,
implemented via a set of SAS macros developed by Tooze and
Grunwald. [24,26]
The independent variables of interest were: circumcision group
(men randomized to receive circumcision versus those randomized
to remain uncircumcised); time (indicator variables for 6 month
and 12 month follow-up); and the interaction between circumci-
sion group and time. Additional covariates included age, marital
status, education, income and the belief that circumcision reduces
risk of acquiring HIV.
The secondary outcome variable included information on
whether or not men were diagnosed with an incident infection
of Neisseria gonorrhoeae, Chlamydia trachomatis,orTrichomonas vaginalis
within 3 months before or after the behavioral interview at the 6
th
and 12 month follow-up visit. Any incident STIs versus none were
modeled using dichotomous random effects models using Proc
NLMIXED. [29]
Results
Between March 2004 and September 2005, 1780 men were
enrolled in the RCT and therefore met eligibility criteria for this
study. Of these, 1319 chose to participate in this study, yielding an
overall response rate of 74%, which surpassed our target
enrollment of 1000. Men who joined this sub-study were slightly
more likely to have been randomized to the control (53%) versus
circumcision (47%) arm (p,0.001), were younger (46% vs. 41%
p = 0.03), more likely to have completed secondary school (58% vs.
52%, p = 0.03), and more likely to be unemployed (67% vs. 60%,
p = 0.02) than those who did not enroll. There were no significant
differences between the median number of lifetime sex partners
(Wilcoxon Two Sample Z Test = 0.01, p = 0.95), number of sex
partners in the last 6 months (x
2
= 0.53, p = 0.77), or occurrence of
a prevalent sexually transmitted infection (x
2
= 0.17, p = 0.68) at
baseline between the men who enrolled in this study versus those
who did not.
Ten men with missing data on key outcome variables were
eliminated from all subsequent analyses. The final sample included
1309 men, of whom 620 (47%) had been randomized to undergo
circumcision and 689 (53%) were controls in the parent RCT.
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Table 1 compares the baseline characteristics of the enrolled
circumcised and uncircumcised men. In general, the groups were
similar, except that uncircumcised men were more likely to be
unemployed (x
2
= 16.1, p = 0.01) and circumcised men were more
likely to be diagnosed with a sexually transmitted infection
(x
2
= 5.6, p = 0.02). In the main RCT, 11 men who were
randomized to the control group became circumcised. Three of
these men enrolled in this study. Of 57 men in the RCT who were
randomized to receive circumcision never received the surgery,
sixteen of these enrolled in this study. To investigate the effect of
these crossovers, we performed an ‘‘as treated’’ analysis, which
yielded the same conclusions as the ‘‘intent to treat’’ analysis,
which we report here.
Of the 1309 men enrolled, 1001 (76%) returned for the 6 month
follow-up and 1007 (77%) returned at 12 months. There was no
differential loss to follow-up between study groups (x
2
= 0.02.,
p = 0.90). Men who were interviewed at all three time points
(n = 873) had slightly higher sexual risk propensity scores ( = 3.4)
than men interviewed at one ( = 3.0) or two ( = 3.3) time points
indicating that men with less risky sexual behavior were more
likely to be lost to follow-up than men with high risk behavior
(Wilcoxon Two Sample Z Test with a continuity correction of
.5 = 21.93, p = 0.054).
Table 2 shows the 18 risk scale items, the STI data, and the
belief that circumcision reduces the risk of HIV by group and time.
There were no statistically significant differences between the
proportion of circumcised and uncircumcised men who engaged in
any of the 18 behaviors at any time point. Moreover, both
circumcised and uncircumcised men reported lower numbers of
total sex partners and lower numbers of partners with whom they
did not always use a condom at follow-up visits than they did at
baseline. Of note, circumcised men were no more likely to report
the belief that circumcision reduces the risk of acquiring HIV than
uncircumcised men at any time point. At baseline, 57% of
circumcised and 56% of uncircumcised men reported that they
thought circumcision reduces the risk of HIV. However by the 12
month follow-up visit, endorsement of this belief rose to 75% of
circumcised and 76% of uncircumcised men.
Both groups were diagnosed with fewer incident sexually
transmitted infections at the 12 month follow-up visit compared
to the 6 month visit. Because infections at baseline were considered
prevalent and not incident, a direct comparison cannot be made
from baseline to follow-up visits. However, when looking at the
proportion of men diagnosed with an STI, circumcised men were
more likely than uncircumcised men to be diagnosed with a
prevalent infection at baseline (OR = 1.6, p = 0.02) and an incident
infection at the 6 month follow-up visit (OR = 1.8, p = 0.05). At the
12 month follow-up visit, there were no significant differences
between the proportions of circumcised and uncircumcised men
diagnosed with incident STIs.
Median risk scores declined for all men (circumcised and
uncircumcised) (Figure 1). Declining risk is confirmed by the two-
part random effects regression models (Table 3). In the crude
model evaluating circumcision and time, at the 6 month follow-up
visit men were 57% less likely to engage in any sexual activity
(OR = 0.43, 95% CI 0.34–0.54), and among men who had sex,
there was a 12% decrease (expb = 0.88, 95% CI 0.86–0.90) in risk
scores compared to the baseline visit. Similarly, at the 12 month
follow-up visit, men were 59% less likely to engage in any sex
(OR = 0.41, 95% CI 0.33–0.51) and, of those who did, there was a
16% decrease in risk scores (expb = 0.84, 95% CI 0.81–0.86)
compared to baseline. There was no statistically significant
difference in the risk scores of circumcised and uncircumcised
men (OR = 1.09, 95% CI 0.86–1.38 for logistic and expb = 1.02,
95% CI 0.99–1.01 for lognormal). Similarly, as shown in table 3,
the interaction terms for circumcision group and time were not
significant at the 6 month follow-up visit (OR = 1.27, 95% CI
0.83–1.95 for logistic and expb = 1.01, 95% CI 0.96–1.06 for
lognormal) or the 12 month follow-up visit (OR = 1.21, 95% CI
0.79–1.86 for logistic and expb = 1.03, 95% CI 0.98–1.07 for
lognormal). Thus, there was no evidence of differential risk
Table 1. Baseline Comparability of Men in Circumcised and
Uncircumcised Group (n = 1309)*
Variable
Circumcised Uncircumcised
p-value
n = 620 n = 689
n%N%
Age
18–20 342 55 366 53 0.46
21–24 278 45 323 47
Language of Interview**
English 355 57 418 61 0.32
DhoLuo 256 41 265 38
Kiswahili 9 1 6 1
Education**
Primary (0–8) 116 19 129 19 0.10
Secondary (9–12) 353 57 391 57
Post-Secondary (13 or more) 151 24 169 25
Occupation
Professional/Managerial 105 17 137 20 0.01
Service Worker/Casual worker 102 16 110 16
Farmer/fisherman 83 13 64 9
Student 122 20 139 19
Other 64 10 46 7
None 144 23 203 29
Income
2000 ksh/month or less 360 58 425 62 0.17
More than 2000 ksh/month 261 42 264 38
Marital Status
Married/cohabitating 42 7 50 7 0.73
Single 578 93 639 93
Age at Sexual Debut
,15 274 44 282 41 0.23
. = 15 346 56 407 59
Number of Sex Partners last 6 mo
None 46 7 50 7 0.89
One 259 42 277 40
Two 159 26 176 26
Three or more 156 25 186 27
Diagnosed with a STI at baseli ne
Yes 6510477 0.02
No 555 90 642 93
Lifetime Sex Partners Median = 5.0 Median = 5.0 0.72
IQR = 1–8 IQR = 1–9
*
16 men in ‘‘circumcised’’ group did not actually receive circumcisions and 3
men in the ‘‘uncircumcised’’ group received circumcisions.
**
Percentages do not add up to 100 because of rounding .
doi:10.1371/journal.pone.0002443.t001
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Table 2. Sexual Risk Scale Items for Circumcised and Uncircumcised Men at Baseline, 6 and 12 Month Follow-up Visits*
Variable
Baseline 6 M Follow-up 12 M Follow-up
n = 1309 n = 1001 n = 1007
Circ Uncirc Circ Uncirc Circ Uncirc
Total number of sex partners:
2 or more 315 (51) 363 (53) 185 (39) 200 (38) 177 (37) 206 (39)
1 259 (42) 277 (40) 216 (46) 236 (44) 222 (47) 235 (44)
0 46 (7) 49 (7) 69 (15) 95 (18) 75 (16) 92 (17)
Had unprotected sex with more than 1 partner:
Yes 172 (28) 190 (28) 80 (17) 73 (14) 64 (14) 64 (12)
No 448 (72) 499 (72) 390 (83) 458 (86) 410 (86) 469 (88)
Had unprotected sex with more than 1 ‘‘regular’’ partner:
Yes 114 (18) 117 (17) 35 (7) 36 (7) 33 (7) 32 (6)
No 506 (82) 572 (83) 435 (93) 495 (93) 441 (93) 501 (94)
Had unprotected sex with more than 1 ‘‘casual’’ partner:
Yes 38 (6) 48 (7) 22 (5) 18 (3) 10 (2) 21 (4)
No 582 (94) 641 (93) 448 (93) 513 (97) 464 (98) 512 (96)
Total number of unprotected partners (e.g. partners with whom a
condom was not always worn):
2 or more 172 (28) 190 (28) 80 (17) 73 (14) 64 (14) 64 (12)
1 275 (44) 292 (42) 181 (39) 197 (37) 195 (41) 205 (38)
0 173 (28) 207 (30) 209 (44) 261 (49) 215 (45) 264 (50)
Had a concurrent partnership:
Yes 284 (46) 329 (48) 154 (33) 164 (31) 78 (16) 81 (15)
No 336 (54) 360 (52) 316 (67) 367 (69) 396 (84) 450 (85)
Had sex while a partner was menstruating:
Yes 90 (15) 96 (14) 58 (12) 57 (11) 55 (12) 55 (10)
No 530 (85) 593 (86) 412 (88) 474 (89) 419 (88) 478 (90)
Had sex with a partner after knowing her , = day:
Yes 106 (17) 119 (17) 58 (12) 57 (11) 43 (9) 59 (11)
No 516 (83) 570 (83) 412 (88) 474 (89) 431 (91) 474 (89)
Had unprotected sex after knowing a partner , = day:
Yes 31 (5) 44 (6) 17 (4) 16 (3) 9 (2) 12 (2)
No 589 (95) 645 (94) 453 (96) 515 (97) 465 (98) 522 (98)
Had sex with a commercial sex worker:
Yes 37 (6) 30 (4) 16 (3) 14 (3) 11 (2) 15 (3)
No 583 (94) 659 (96) 454 (97) 517 (97) 463 (98) 518 (97)
Had unprotected sex with a commercial sex worker:
Yes 8 (1) 11 (2) 2 (,1) 3 (1) 1 (,1) 2 (,1)
No 612 (99) 678 (98) 468 (99) 528 (99) 473 (99) 531 (99)
Ever exchange money or gifts for sex with a partner not reported
to be a commercial sex worker:
Yes 113 (18) 116 (17) 47 (10) 46 (9) 35 (7) 44 (8)
No 507 (82) 579 (83) 423 (90) 485 (91) 439 (93) 489 (92)
Always exchange money or gifts for sex with a partner not reported
to be a commercial sex worker:
Yes 13 (2) 18 (3) 5 (1) 4 (1) 3 (1) 7 (1)
No 607 (87) 671 (97) 465 (99) 527 (99) 471 (99) 526 (99)
Believed that a partner had any other sexual partners at the time
of the relationship:
Yes 272 (44) 311 (45) 151 (32) 163 (31) 130 (27) 141 (26)
No 348 (56) 378 (55) 319 (68) 368 (69) 344 (73) 392 (74)
Circumcision and Risk Behavior
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Page 5
according to circumcision group. Because it was not statistically
significant, the interaction terms for circumcision status and visit
were not included in the adjusted model. The random effects
variance in both parts of the model was significant (p,0.01 for
both) demonstrating that there was heterogeneity among men with
respect to engaging in any sexual activity and in risk scores.
After adjusting for age, marital status, education, income, and
the belief that circumcision status reduces the risk of acquiring
HIV, there was still a significant decline in risk scores at the 6 and
12 month follow-up visits compared to baseline. Circumcision
group remained non-significant. Men who were married or
cohabitating with a woman were more likely to engage in any
sexual activity (OR = 10.29, 95% CI 4.19–25.5) and had slightly
higher mean risk scores (expb = 1.02, 95% CI 0.98–1.06) than
single men. Similarly, men who earned less than 2000 ksh/month
(approximately $27 US) were less likely to engage in any sexual
activity (OR = 0.69, 95% CI 0.53–0.89) and had lower mean risk
scores (expb = 0.96, 95% CI 0.94–0.98). Of note, although the
proportion of men reporting the belief that circumcision reduces
the risk of acquiring HIV increased from baseline (57%) to the 12
Figure 1. Median Risk Scores for Circumcised and Uncircumcised Men at Baseline, 6 and 12 month follow-up visits.
doi:10.1371/journal.pone.0002443.g001
Table 2. cont.
Variable
Baseline 6 M Follow-up 12 M Follow-up
n = 1309 n = 1001 n = 1007
Circ Uncirc Circ Uncirc Circ Uncirc
Believed that a partner had other ‘‘regular’’ sexual partners
at the time of the relationship:
Yes 221 (45) 274 (49) 126 (45) 131 (44) 106 (38) 125 (40)
No 273 (55) 288 (51) 153 (55) 168 (56) 176 (62) 185 (60)
Believed that a partner had other ‘‘casual’’ sexual partners
at the time of the relationship:
Yes 231 (49) 257 (47) 130 (47) 140 (47) 118 (43) 135 (43)
No 245 (51) 284 (53) 146 (53) 159 (53) 158 (57) 178 (57)
Believed that a partner had sex with other partners for money
or gifts at the time of the relationship:
Yes 136 (29) 153 (29) 70 (26) 64 (22) 41 (16) 54 (19)
No 327 (71) 369 (71) 202 (74) 230 (78) 216 (84) 233 (81)
Believed that a partner had HIV/AIDS:
Yes 17 (3) 11 (2) 10 (2) 6 (1) 3 (1) 8 (2)
No 603 (97) 678 (98) 460 (98) 525 (99) 471 (99) 525 (98)
Believed Circumcision reduces risk of acquiring HIV*
Yes 356 (57) 387 (56) 319 (68) 373 (70) 357 (75) 405 (76)
No 265 (43) 302 (44) 152 (32) 158 (30) 118 (25) 129 (24)
Laboratory Diagnosed infection of gonorrhea, chlamydia, or trichomoniasis*
Yes 65 (10) 47 (7) 27 (6) 17 (3) 10 (2) 14 (3)
No 555 (90) 642 (93) 443 (94) 514 (97) 464 (98) 518 (97)
*
These variables are not included in the 18-item scale.
doi:10.1371/journal.pone.0002443.t002
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Page 6
month follow-up visit (76%), this belief was not associated with
engaging in any sexual activity (OR 1.09, 95% CI 0.87–1.36) or in
higher risk scores (expb = 1.00, 95% CI 0.97–1.02).
Table 4 presents the results of the crude model with
circumcision and time, the model including the interaction
between circumcision and time, and the adjusted random effect
regression models comparing incident STIs at the 12 month visit
compared to the 6 month visit. Like risk scores, circumcision was
not associated with a statistically significant increase in STIs in the
crude (OR 1.28, 95% CI 0.82–2.00) or adjusted models (OR 1.25,
95% CI 0.79–2.00). Fewer men were diagnosed with incident STIs
at the 12 month visit compared to the 6 month visit (adjusted OR
0.55, 95% CI 0.34–0.88). The interaction between circumcision
status and time indicated that circumcised men were slightly less
likely to be diagnosed with an STI at the 12 month visit than their
uncircumcised counterparts, but the term was not statistically
significant (OR = 0.49, 95% CI 0.21–1.21).
Discussion
We used two different measures of sexual risk to evaluate risk
compensation associated with male circumcision: an index based
on 18 sexual behaviors and laboratory diagnosed STIs. We found
no evidence to suggest that circumcised men engaged in increased
Table 4. Results of the Dichotomous Random Effects Regression Models for Incident Infections of Gonorrhea, Chlamydia, or
Trichomoniasis, Circumcision Status, and Time With and Without Covariates
Crude Model Group by Time
Crude Model with Group by Time
Interaction Adjusted Model*
OR{ (p-value) 95% CI OR{ (p-value) 95% CI OR{ (p-value) 95% CI
Circumcised vs. uncircumcised 1.28 (0.28) 0.82–2.00 1.65 (0.08) 0.94–2.88 1.25 (0.34) 0.79–2.00
12 compared to 6 month visit 0.57 (0.01) 0.36–0.89 0.82 (0.52) 0.44–1.53 0.55 (0.01) 0.34–0.88
Circumcision by change from 6 to 12 month visit 0.49 (0.12) 0.20–1.21
Prevalent STI at baseline visit 3.07 (0.01) 1.65–5.71
Age (continuous) 0.99 (0.85) 0.85–1.14
Married/cohabitating vs. single 1.02 (0.96) 0.52–1.97
Primary school or less vs. more 1.03 (0.92) 0.57–1.86
,2000 ksh/month vs. . = 2000 ksh/month 0.40 (0.01) 0.24–0.66
Believed circumcision reduces risk of HIV 1.09 (0.73) 0.65–1.84
Random Effects s
2
1.09 1.02 0.80
*
The following co-variates were adjusted for: age, marital status, education, and income.
{
All odds ratios are population averaged, subject-specific not shown.
doi:10.1371/journal.pone.0002443.t004
Table 3. Results of the Two-Part Random Effects Regression Modeling the Sexual Risk Score, Circumcision Status, and Time With
and Without Covariates
Crude Model Circumcision and Time
Crude Model with Group by Time
Interaction Adjusted Model
Sexually Active
(y/n) Logistic
Risk Scores .0
Lognormal
Sexually Active
(y/n) Logistic
Risk Scores .0
Lognormal
Sexually Active
(y/n) Logistic
Risk Scores
.0 Lognormal
Expb (95 % CI) Expb (95 % CI) Expb (95 % CI) Expb (95 % CI) Expb (95 % CI) Expb (95 % CI)
Circumcised vs. uncircumcised 1.09 (0.86–1.38) 1.02 (0.99–1.01) 0.92 (0.64–1.33) 1.01 (0.97–1.04) 1.07 (0.85–1.36) 1.01 (0.98–1.03)
6 month visit vs. baseline 0.43 (0.34–0.54) 0.88 (0.86–0.90) 0.39 (0.29–0.52) 0.88 (0.85–0.91) 0.40 (0.32–0.51) 0.90 (0.87–0.92)
12 month visit vs. baseline 0.41 (0.33–0.51) 0.84 (0.81–0.86) 0.37 (0.28–0.51) 0.84 (0.81–0.86) 0.37 (0.29–0.47) 0.86 (0.84–0.89)
Circumcision and 6 month visit 1.27 (0.83–1.95) 1.01 (0.96–1.06)
Circumcision and 12 month visit 1.21 (0.79–1.86) 1.03 (0.98–1.07)
Age (continuous) 1.00 (0.93–1.08) 1.00 (0.99–1.00)
Married/cohabitating vs. single 10.29 (4.19–25.5) 1.02 (0.98–1.06)
Primary school or less vs. more 1.12 (0.81–1.55) 1.03 (1.00–1.06)
,2000 vs. . = 2000 0.69 (0.53–0.89) 0.96 (0.94–0.98)
Believed circumcision reduces risk of
HIV
1.09 (0.87–1.36) 1.00 (0.97–1.02)
In the logistic part of the model, exponentiated betas represent population averaged odds ratios.
In the lognormal portion of the model represent, exponentiated betas represent % change in Y (risk score), per change in unit X.
In the adjusted model, the following covariates were adjusted for: age, marital status, education, income, and belief that circumcision reduces the risk of acquiring HIV.
doi:10.1371/journal.pone.0002443.t003
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Page 7
risk behavior after the procedure. To the contrary, both
circumcised and uncircumcised men significantly reduced their
HIV risk behavior from baseline to the 6 and 12 month follow-up
visits. This decline was evident when evaluating the overall risk
score across time and by comparing the individual 18 behaviors at
a given time point. There was also a decline in the number of
incident infections of gonorrhea, chlamydia and trichomoniasis
from the 6 month visit to the 12 month visit. The overall
consistency of the self-reported sexual behavior data with the
biologic indicator (STI) likely indicates a low degree of
misreported sexual behavior.
Circumcised men were slightly more likely to be diagnosed with
incident STIs than uncircumcised men at the 6 month visit (6% vs.
3%, p = 0.05). However, it is important to note that circumcised
men were also more likely to be diagnosed with an STI at baseline
(10% vs. 7%, p = 0.02). Even though all men received treatment
and referrals for their partners to receive treatment, it is possible
that sex partners did not receive treatment and potentially re-
infected the men. Ideally, we would have compared incident
infections at all three time points, but it was not possible to
disentangle prevalent from incident infections at the baseline visit.
Given that limitation, longitudinal analyses indicated that incident
STIs declined from the 6 month to the 12 month visit and there
was no interaction between circumcision and time.
In general, our findings are consistent with most empirical studies
of behavioral disinhibition in the context of male circumcision.
[2,3,15] This sub-study included approximately half the participants
enrolled in the RCT, but used a different methodology that was
specifically designed to assess a comprehensive combination of risk
behaviors. Instead of focusing on 5 sexual risk behaviors as was done
in the RCT, we evaluated 18 risk behaviors/sexual practices and
evaluated the occurrence of incident STIs. Similar to the conclusions
drawn from the trials in Kenya and Uganda and a prospective study
in Siaya and Bondo districts in Kenya, we found no compelling
evidence of increased risk behavior among circumcised men.
[2,3,15] As was the case in the overall results from the Kenyan
trial, we detected an equal reduction in risky sexual practices among
both circumcised and uncircumcised men. [2] That the results from
the RCT and from this study were consistent strengthens the
conclusions of both studies. These are important results in the face of
reluctance on the part of some in the international health community
to endorse male circumcision. [30] The consistency and strength of
the results presented in this study, the RCT, and in previous studies,
[1–3,15] provide evidence that risk compensation is likely to be
minimal or absent among circumcised men and, therefore, it should
not aprioribe considered a barrier to the promotion of male
circumcision for HIV and STI prevention.
There were several limitations to this study. All the participants
were from a narrow age range (18–24 years) and were enrolled in
a RCT which accepted only healthy, sexually active HIV-
uninfected individuals. When MC services are made widely
available, it is likely that men and boys from a wide spectrum of
ages will access the services and, in the absence of HIV testing,
some may be HIV infected prior to circumcision. Of those eligible
for this study, 74% enrolled. We found no differences in sexual
behavior between those enrolled and those not enrolled but
eligible. Nevertheless, there could have been differences that we
were unable to measure. Further, because this was an observa-
tional study, we were unable to control for unknown confounders.
In addition, the participants were followed for only twelve months.
Although logically one might think that risk compensation would
occur soon after wound healing in the circumcised men, it is
possible that circumcised men become less sexually inhibited after
they have been in their new status for more than one year. Finally,
as with all studies that rely on participants’ self-reports,
misreporting of behaviors was possible. Study interviewers were
carefully trained and the questionnaire using the Timeline
Followback approach had many means of checking for inconsis-
tencies. We also used biologic outcomes of risk (STIs), and these
were consistent with the results from the self-reported behaviors.
Participation in the main RCT and in this study entailed repeated
HIV testing and individually-tailored risk reduction counseling at the
baseline, 6 month, and 12 month study visits, and participants were
informed that the evidence for MC having a protective effect against
HIV acquisition was inconclusive. Conditions under which MC is
provided widely are likely to be different. Consequently, despite
there now being consistent findings from five studies that risk
compensation is essentially absent after circumcision, [1–3,15] it will
be necessary to further evaluate the possibility that men increase
their HIV risk behavior after circumcision is offered in more
naturalistic public health and medical settings. Alternatively and
preferably, until further evidence becomes available, as MC services
are introduced and promoted, the HIV prevention community
should ensure that MC services are integrated with a full package of
HIV prevention measures including HIV testing, STI diagnosis and
treatment, condom provision, and risk reduction counseling. The
results of this study suggest that, under such conditions, HIV risk
behaviors after circumcision are unlikely to increase. Indeed, they
may well decline.
Acknowledgments
We thank all of the participants, without whom this work would not have
been possible. We are grateful to Evans Otieno, Nicholas Ouma, Bob
Ogollah, Kevine Kamollah, and the entire UNIM Project staff for their
assistance in data collection and recruitment efforts and to Dr. Donald
Hedeker, Dr. Ronald Hershow, Dr. George Karabatsos and Nelli
Westercamp for their helpful comments on the manuscript and on
statistical analyses.
Author Contributions
Conceived and designed the experiments: RB SM CM. Performed the
experiments: RB CM KA. Analyzed the data: CM RC. Contributed
reagents/materials/analysis tools: RB JN. Wrote the paper: RB SM CM
RC KA JN.
References
1. Auvert B, Taljaar D, Lagarde E, Sobngwi-Tambekou J, Sitta R, et al. (2005)
Randomized, controlled intervention trial of male circumcision for reduction of
HIV infection risk: the ANRS 1265 trial. PLoS Medicine 2: e298.
2. Bailey R, Moses S, Parker CB, Agot K, Maclean I, et al. (2007) Male
circumcision for HIV prevention in young men in Kisumu, Kenya: a
randomised controlled trial. The Lancet 369: 643–656.
3. Gray RH, Kigozi G, Serwadda D, Makumbi F, Watya S, et al. (2007) Male
circumcision for HIV prevention in men in Rakai, Uganda: a randomised trial.
The Lancet 369: 657–666.
4. Siegfried N, Muller M, Deeks J, Volmink J, Egger M, et al. (2005) HIV and male
circumcision–a systematic review with assessment of the quality of studies. The
Lancet Infectious Diseases 5: 165–173.
5. Weiss HA, Quigley MA, Hayes RJ (2000) Male circumcision and risk of HIV
infection in sub-Saharan Africa: a systematic review and meta-analysis. AIDS
14: 2361–2370.
6. Donoval BA, Landay AL, Moses S, Agot K, Ndinya-Achola JO, et al. (2006)
HIV-1 target cells in foreskins of African men with varying histories of sexually
transmitted infections. American Journal of Clinical Pathology 125: 386–391.
7. McCoombe SG, Short RV (2006) Potential HIV-1 target cells in the human
penis. AIDS 20: 1491–1495.
8. NIH/NIAID (2006) Adult Male Circumcision Significantly Reduces Risk of
Acquiring HIV. Trials Kenya and Uganda Stopped Early.
9. UNAIDS/WHO/UNFPA/UNICEF (2005) Press statement: UNAIDS state-
ment on South African trial findings regarding male circumcision and HIV. Rio
Circumcision and Risk Behavior
PLoS ONE | www.plosone.org 8 June 2008 | Volume 3 | Issue 6 | e2443
Page 8
de Jeneiro: UNAIDS, World Health Organization, United Nations Population
Fund, United Nations Children’s Fund.
10. World Health Organization (WHO), the United Nations Population Fund
(UNFPA), the United Nations Children’s Fund (UNICEF), the World Bank, the
UNAIDS Secretariat (2006) Statement on Kenyan and Ugandan trial findings
regarding male circumcision and HIV. Statement developed by the World
Health Organization (WHO), the United Nations Population Fund (UNFPA),
the United Nations Children’s Fund (UNICEF), the World Bank and the
UNAIDS Secretariat. http://wwwwhoint/mediacentre/news/statements/
2006/s18/en/indexhtml, Accessed on December 13, 2006.
11. World Health Organization (2005) UNAIDS statement on South African trial
findings regarding male circumcision and HIV Statement developed by the
World Health Organization (WHO), the United Nations Population Fund
(UNFPA,) the United Nations Children’s Fund (UNICEF) and the UNAIDS
Secretariat, 26 July 2005. http://www.who.int/mediacentre/news/releases/
2005/pr32/en/.
12. Cassell M, Halperin DT, Shelton JD, Stanton D (2006) Risk compensation: the
Achilles’ heel of innovations in HIV prevention. British Medical Journal 332:
605–607.
13. Bailey RC, Neema S, Othieno R (1999) Sexual behaviors and other HIV risk
factors in circumcised and uncircumcised men in Uganda. Journal of Acquired
Immune Deficiency Syndrome 22: 294–301.
14. Seed J, Allen S, Mertens T, Hudes E, Serufilira A, et al. (1995) Male
circumcision, sexually transmitted disease, and risk of HIV. Journal of Acquired
Immune Deficiency Syndromes & Human Retrovirology 8: 83–90.
15. Agot KE, Kiarie JN, Nguyen HQ, Odhiambo JO, Onyango TM, et al. (2007)
Male Circumcision in Siaya and Bondo Districts, Kenya: Prospective Cohort
Study to Assess Behavioral Disinhibition Following Circumcision. Journal of
Acquired Immune Deficiency Syndromes: JAIDS 44: 66–70.
16. Carey MP, Carey KB, Maisto SA, Gordon CM, Weinhardt LS (2001) Assessing
sexual risk behaviour with the Timeline Followback (TLFB) approach:
continued development and psychometric evaluation with psychiatric outpa-
tients. International Journal of STD & AIDS 12: 365–375.
17. Junker B, Sijtsma K (2001) Nonparametric item response theory in action: an
overview of a special issue. Applied Psychological Measurement 25: 211–220.
18. Sjitsma K, Emons WHM, Bouwmeester SB, Nyclic
ˇ
ek I, Roorda LD (2008)
Nonparametric IRT analysis of quality of life scales and its application to the
World Health Organization quality of life scale (WHOQOQ-Bref). Quality of
Life Research 17: 275–290.
19. Mattson C, Bailey RC, Agot K, Ndinya-Achola JO, Moses S (2007) A nested
case-control study of sexual practices and risk factors for prevalent HIV-1
infection among young men in Kisumu, Kenya. Sexually Transmitted Diseases
34: 731–736.
20. Buve A, Weiss HA, Laga M, Van Dyck E, Musonda R, et al. (2001) The
epidemiology of trichomoniasis in women in four African cities. AIDS 15 Suppl
4: S89–96.
21. Buve A, Weiss HA, Laga M, Van Dyck E, Musonda R, et al. (2001) The
epidemiology of gonorrhoea, chlamydial infection and syphilis in four African
cities. AIDS 15 Suppl 4: S79–88.
22. Gray Ra, Azire Jb, Serwadda Dc, Kiwanuka Nb, Kigozi Gb, et al. (2004) Male
circumcision and the risk of sexually transmitted infections and HIV in Rakai,
Uganda. AIDS December 18: 2428–2430.
23. Reynolds SJ, Shepherd ME, Risbud AR, Gangakhedkar RR, Brookmeyer RS,
et al. (2004) Male circumcision and risk of HIV-1 and other sexually transmitted
infections in India. Lancet 363: 1039–1040.
24. Pequegnat W, Fishbein M, Celentano D, Ehrhardt A, Garnett G, et al. (2000)
NIMH/APPC workgroup on behavioral and biological outcomes in HIV/STD
prevention studies: a position statement. Sexually Transmitted Diseases 27:
127–132.
25. Hu F, Goldberg JG, Hedeker D, Flay BR, Pentz M (1998) Comparison of
population-averaged and subject-specific approaches for analyzing repeated
binary outcomes. American Journal of Epidemiology 147: 694–703.
26. Olsen M, Schafer JL (2001) A two-part random-effects model for semicontin-
uous longitudinal data. Journal of the American Statistical Association 96:
730–745.
27. Tooze J, Grunwald GK, Jones R (2002) Analysis of repeated measures data with
clumping at zero. Statistical Methods in Medical Research 11: 341–355.
28. Xie H, McHugo G, Sengupta A, Clark R, Drake R (2004) A method for
analyzing longitudinal outcomes with many zeros. Mental Health Services
Research 6: 239–246.
29. SAS Version 8.2 & 9.1 (2002, 2004) Cary, NC, SAS Institute.
30. Klausner J, Wamai RG, Bowa K, Agot K, Kagimba J, et al. (2008) Is male
circumcision as good as the HIV vaccine we’ve been waiting for? Future
Medicine 2: 1–7.
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  • Source
    • "In a study conducted in Uganda one Randomized Controlled Trial (RCT) found very little evidence of behavioral disinhibition or risk compensation among men who had undergone circumcision [23]. Mattson et al. [16] utilized a different measure of risky behavior a risk scale, and found no significant differences in their 18-item sexual risk propensity scores between circumcised and uncircumcised men. There are many factors that may offset risk compensation among men who have undergone male circumcision and that could explain why this study did not find any significant associations between circumcision type and risk perception. "
    [Show abstract] [Hide abstract] ABSTRACT: Background In South Africa, voluntary medical male circumcision (VMMC) has recently been implemented as a strategy for reducing the risk of heterosexual HIV acquisition among men. However, there is some concern that VMMC may lead to low risk perception and more risky sexual behavior. This study investigated HIV risk perception and risk behaviors among men who have undergone either VMMC or traditional male circumcision (TMC) compared to those that had not been circumcised. Methods Data collected from the 2012 South African national population-based household survey for males aged 15 years and older were analyzed using bivariate and multivariate multinomial logistic regression, and relative risk ratios (RRRs) with 95 % confidence interval (CI) were used to assess factors associated with each type of circumcision relative no circumcision. Results Of the 11,086 males that indicated that they were circumcised or not, 19.5 % (95 % CI: 17.9–21.4) were medically circumcised, 27.2 % (95 % CI: 24.7–29.8) were traditionally circumcised and 53.3 % (95 % CI: 50.9–55.6) were not circumcised. In the final multivariate models, relative to uncircumcised males, males who reported VMMC were significantly more likely to have had more than two sexual partners (RRR = 1.67, p = 0.009), and males who reported TMC were significantly less likely to be low risk alcohol users (RRR = 0.72, p < 0.001). Conclusion There is a need to strengthen and improve the quality of the counselling component of VMMC with the focus on education about the real and present risk for HIV infection associated with multiple sexual partners and alcohol abuse following circumcision.
    Full-text · Article · Apr 2016 · BMC Public Health
  • Source
    • "First, overestimating the efficacy of MC could result in risk compensation, whereby perceived protection leads men to reduce other protective behaviors such as condom use, monogamy, or age of sexual debut, and women to decrease their caution with respect to condom use or learning their partner's HIV status. While evidence for risk compensation is limited within existing RCTs [16, 17], one prospective cohort study in Nyanza found no evidence of risk compensation in the context of Kenya's VMMC program [18]. Second, underestimating the protective effects of MC could undermine the demand for MC, both for adult males and for male children and infants. "
    [Show abstract] [Hide abstract] ABSTRACT: Women’s perceptions of male circumcision (MC) have implications for behavioral risk compensation, demand, and the impact of MC programs on women’s health. This mixed methods study combines data from the first two rounds of a longitudinal study (n = 934) and in-depth interviews with a subsample of respondents (n = 45) between rounds. Most women correctly reported that MC reduces men’s risk of HIV (64% R1, 82% R2). However, 30% of women at R1, and significantly more (41%) at R2, incorrectly believed MC is fully protective for men against HIV. Women also greatly overestimated the protection MC offers against STIs. The proportion of women who believed MC reduces a woman’s HIV risk if she has sex with a man who is circumcised increased significantly (50% to 70%). Qualitative data elaborate women’s misperception regarding MC. Programs should address women’s informational needs and continue to emphasize that condoms remain critical, regardless of male partner’s circumcision status.
    Full-text · Article · Mar 2016 · PLoS ONE
    • "Lack of understanding about partial efficacy could impact on risky sexual behavior, putting people at increased risk for HIV infection. Previous research shows varied levels of concern about behavioral disinhibition (Albert et al., 2011; De Bruyn et al., 2010; Herman-Roloff et al., 2011; Milford et al., 2012), but less evidence of its occurrence (Ayiga and Letamo, 2011; Mattson et al., 2008; Maughan-Brown and Venkataramani, 2012). Despite the limited evidence of overall increased risk behavior in clinical trial situations, and limited studies of this behavior outside of these conditions, behavioral disinhibition in even a small number of individuals might put these individuals and their partners at increased risk of HIV infection. "
    [Show abstract] [Hide abstract] ABSTRACT: Medical male circumcision has been shown to reduce HIV transmission to an uninfected male partner. In South Africa, medical male circumcision programs were rolled-out in 2010. Prior to roll-out, we explored healthcare providers' knowledge, attitudes and practices about medical male circumcision and their understandings of partial efficacy for HIV prevention. We conducted qualitative research, using in-depth interviews. Participants were from three rural and three urban primary healthcare clinics, randomly selected in eThekwini District, KwaZulu-Natal. 25 healthcare providers (including nurse managers, nurses and counselors) were purposively selected from the clinics. In-depth interviews were recorded, transcribed and translated. Independent researchers reviewed the transcripts and developed a codebook based on emergent themes, using thematic analysis. NVivo 8 was used to facilitate data management, coding and analysis. Although most providers had heard that medical male circumcision can reduce risk of HIV acquisition in men, most did not have accurate scientific understandings of this. Some providers had misperceptions about the limited/partial protection medical male circumcision offers. Many had concerns that their communities would misunderstand it, causing increased risky sexual behavior. These data provide a baseline of providers' understandings of medical male circumcision prior to roll-out, and can be used to compare current data and ensure accurate messaging to clients. Healthcare provider messaging should build client understandings of the meaning of partially efficacious technologies. Copyright © 2015 Elsevier Ltd. All rights reserved.
    No preview · Article · Aug 2015 · International journal of nursing studies
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