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MEDICC Review, October 2012, Vol 14, No 4
26
Original Research
Peer Reviewed
INTRODUCTION
The AIDS epidemic has drawn attention worldwide and has been
a national concern in Vietnam. The epidemic in Vietnam is clas-
sifi ed as a concentrated epidemic with high prevalence among
defi ned high-risk groups, mainly injection drug users, with lower
prevalence in the general population. HIV-positive cases have
been reported in all 63 Vietnamese cities. As of December 31,
2009, there were 160,019 reported HIV cases and 44,050 deaths
due to AIDS-related illnesses. In 2009 alone, there were 15,713
newly reported HIV cases and 2010 AIDS-related deaths.[1]
Recent projections showed that by 2012, approximately 280,000
people would be living with HIV, but this fi gure may still be
underestimated due to the sensitive nature of the condition and
potential limitations of the national HIV case reporting system.
[1] In order to implement effective intervention activities, Vietnam
needs accurate data on HIV/AIDS infections and high-risk behav-
iors in the population.
Until now, several routine surveys and surveillance systems have
been used in Vietnam to collect data on high-risk behaviors, most-
ly carried out in high-risk groups.[2,3] Since high-risk behavior is
a sensitive topic, data are subject to recall bias as well as inten-
tional under-reporting by respondents. Audio computer-assisted
self interview (ACASI) has received attention as a method for col-
lecting sensitive information among youth in developed-country
settings such as the USA,[4] as well as in developing countries in
Africa and elsewhere.[5–7] Instead of providing answers directly
to interviewer questions, respondents read questions displayed
on a laptop screen while listening to the same question through
audio headphones. Respondents enter responses on an external
mini keypad or regular laptop keyboard, without presence of inter-
viewers. ACASI has been well received in many countries and is
considered to provide more reliable information than other data
collection methods, particularly in HIV-related studies.[5–8]
In developing-country pilots, ACASI has shown good results,[5,8]
with authors fi nding that it reports sensitive behaviors with better
confi dentiality and higher accuracy and also facilitates data man-
agement.[9] In recent years, the technique has been applied in
Vietnam to study adolescent and youth health;[10] Le and Blum
found that ACASI showed advantages with regard to respondent
attitudes and perceptions of sensitive topics in such research.
This work revealed higher prevalence rates for sensitive and stig-
matized behaviors (such as unmarried youth having multiple sex-
ual partners and having sex with sex workers) than did traditional
survey methods.[10.11] However, ACASI has not been used in
studies of Vietnam’s adult population.
The US President’s Emergency Plan for AIDS Relief (PEPFAR)
supported MACRO International to partner with the Vietnam
General Statistical Offi ce and National Institute of Hygiene and
Epidemiology to conduct the AIDS Indicator Survey in Vietnam
starting in 2005. This household-based survey of the general
population aged 15 to 49 years generated important informa-
tion on knowledge, attitudes and practices related to HIV risk.
[3] However, traditional face-to-face interview methods may
Audio Computer-Assisted Self Interview Compared to Traditional
Interview in an HIV-Related Behavioral Survey in Vietnam
Linh Cu Le MD MS PhD and Lan T.H. Vu MD PhD
ABSTRACT
INTRODUCTION Globally, population surveys on HIV/AIDS and other
sensitive topics have been using audio computer-assisted self inter-
view for many years. This interview technique, however, is still new to
Vietnam and little is known about its application and impact in general
population surveys. One plausible hypothesis is that residents of Viet-
nam interviewed using this technique may provide a higher response
rate and be more willing to reveal their true behaviors than if inter-
viewed with traditional methods.
OBJECTIVE This study aims to compare audio computer-assisted
self interview with traditional face-to-face personal interview and self-
administered interview with regard to rates of refusal and affi rmative
responses to questions on sensitive topics related to HIV/AIDS.
METHODS In June 2010, a randomized study was conducted in three
cities (Ha Noi, Da Nan and Can Tho), using a sample of 4049 residents
aged 15 to 49 years. Respondents were randomly assigned to one of
three interviewing methods: audio computer-assisted self interview,
personal face-to-face interview, and self-administered paper inter-
view. Instead of providing answers directly to interviewer questions
as with traditional methods, audio computer-assisted self-interview
respondents read the questions displayed on a laptop screen, while
listening to the questions through audio headphones, then entered
responses using a laptop keyboard. A MySQL database was used
for data management and SPSS statistical package version 18 used
for data analysis with bivariate and multivariate statistical techniques.
Rates of high risk behaviors and mean values of continuous variables
were compared for the three data collection methods.
RESULTS Audio computer-assisted self interview showed advantages
over comparison techniques, achieving lower refusal rates and reporting
higher prevalence of some sensitive and risk behaviors (perhaps indica-
tion of more truthful answers). Premarital sex was reported by 20.4% in
the audio computer-assisted self-interview survey group, versus 11.4%
in the face-to-face group and 11.1% in the self-administered paper ques-
tionnaire group. The pattern was consistent for both male and female
respondents and in both urban and rural settings. Men in the audio com-
puter-assisted self-interview group also reported higher levels of high-risk
sexual behavior—such as sex with sex workers and a higher average
number of sexual partners—than did women in the same group. Impor-
tantly, item refusal rates on sensitive topics tended to be lower with audio
computer-assisted self interview than with the other two methods.
CONCLUSIONS Combined with existing data from other countries
and previous studies in Vietnam, these fi ndings suggest that research-
ers should consider using audio computer-assisted self interview for
future studies of sensitive and stigmatized topics, especially for men.
KEYWORDS Behavioral research, community surveys, public health
surveillance/methods, survey methods, effect modifi er, epidemiologic
biases, social desirability, HIV/AIDS, Vietnam
27
MEDICC Review, October 2012, Vol 14, No 4 Peer Reviewed
Original Research
have resulted in under-reporting of risk behaviors. Since then,
no advanced techniques for sensitive data collection have been
applied in Vietnam in the general population. Thus, it would be
essential to conduct a pilot community-based survey of the pop-
ulation aged 15 to 49 years to fi eld test ACASI, given the previ-
ous preliminary experiences of its application in young people
mentioned above.
It should be noted that ACASI is not the only technique able to
facilitate confi dentiality and help get more valid results on sensi-
tive topics. The randomized response technique (RRT) proposed
by Warner[12] has been tested and validated and its use is well
established.[13–16] However, its applicability has not been tested
in Vietnam. Moreover, its application would have required signifi -
cant extra preparation, time and effort on the part of the interview
team to explain the process to interviewees, and data analysis
and interpretation would not be as straightforward as with ACASI.
Finally, a recent meta-analysis found no advantage of RRT over
ACASI.[15] Hence, we did not consider piloting RRT or a combi-
nation of RRT and ACASI, which would have made the research
unnecessarily complicated.
This study aimed to compare ACASI with traditional face-to-face
personal interview (PI) and self-administered paper-and-pencil
interview (SA) with regard to effectiveness of data collection, affi r-
mative response rates on sensitive questions, item refusal rates
and survey refusal rates.
METHODS
Study design and sample This was a cross-sectional commu-
nity pilot survey. Three cities with rural districts within their juris-
diction were selected in different geographic regions of Vietnam:
Ha Noi (capital city in the Red River Delta in the north), Da Nang
(coastal city in central Vietnam) and Can Tho (in the Mekong
River Delta, southern Vietnam). Individuals aged 15 to 49 years
by June 1, 2010 in selected households were randomized into
three groups: face-to-face personal interview administration (PI),
pencil-and-paper self-administered interview (SA), and ACASI.
Survey sample design satisfi ed basic requirements for compara-
bility among the three data collection methods and disaggregation
by rural and urban location.
Multistage cluster sampling was used. We assumed there could
be differences between men and women in willingness to report
sensitive information; thus, each interview-method group includ-
ed both sexes, making six groups in total for analysis. Sample
size was calculated based on the two-sided test of comparison
between groups and the following parameters: signifi cance of
95%; power of 90%; p1= 0.05 (based on prevalence of youth in
previous studies who exhibited risk behaviors regarding injection
drug use and sexual habits). The difference to be detected was 10
percentage points (it is hypothesized that if p1= 0.05, then p2, the
prevalence found in another interview method, would be 0.15);
design effect = 1.2 (based on a previous study of this type in Viet-
nam);[10] allowing for 5% nonresponse. With these parameters,
the anticipated sample for each cluster was 770, for a total of
4620 persons aged 15 to 49 years in 6 clusters (male and female
for each survey method arm).
With the above estimated sample size in the three cities, two dis-
tricts were randomly selected in each (one urban and one rural),
with a total of 770 study participants in each district. Based on
Vietnam’s 2009 census data, in order to reach 770 subjects, we
randomly selected 330 households in each district: of those, 110
households would be interviewed with ACASI, 110 with SA and
110 with PI. Three communes (subunits of districts) were selected
in each district. Households selected by health care workers were
required to have at least one resident aged 15 to 49. The fi nal
list was entered into a computer program to generate a random
code for assigning mode of interview, this information provided to
supervisors and data surveyors for each group.
Instrument design and data collection To provide quality esti-
mates for indicators in a manner that would facilitate international
comparison, data were collected through two types of question-
naire: a household questionnaire and an individual questionnaire,
used for both female and male respondents. The individual ques-
tionnaire included the following main sections: a) personal back-
ground; b) reproduction and pregnancy; c) marriage and sexual
activities; d) attitudes/social norms with regard to HIV/AIDS; e)
awareness and knowledge of sexually transmitted infections. The
questionnaires were adapted from the 2006 Vietnam Population
and AIDS Indicator Survey[3] and a previous survey of young
people in Vietnam,[10] transferred to a database and installed on
laptop computers. The questionnaires were also voice recorded
and integrated into the ACASI interview software, which is based
on Net programming language, using an MS SQL database. Esti-
mated survey completion time was 45 minutes. The usual demo-
graphic profi le and household/living conditions questions were
asked in all households face-to-face, then the individual ques-
tionnaire was administered in one of three randomly-assigned
interview modes. For each of the three data collection methods,
interviewers/data collectors were matched by sex with study par-
ticipants. All interviewers were aged 20 to 30 years; they received
interviewing skills training and participated in a small-scale fi eld
pilot prior to starting data collection.
Ethical procedures All data were collected in the respondent’s
home after written informed consent. Parental consent was
obtained for those aged <18 years at time of data collection. No
name, personal identifi cation or identifying characteristics were
recorded on individual survey forms at any time. Each house-
hold form was assigned a unique ID to permit later merging with
individual forms from that household and no link could be made
between household background and personal identity. All infor-
mation remained confi dential, following standard procedures to
avoid identifi cation of households or individuals during analysis.
The study protocol was approved by the Hanoi School of Public
Health ethics committee and the Institutional Review Board at the
US Centers for Disease Control and Prevention.
Data analysis and interpretation Face-to-face interview ques-
tionnaire and self-administered paper-and-pencil questionnaire
data were merged with ACASI into a single data set. Household
characteristics information collected in all three groups using the
same face-to-face interview sheet was also entered and merged
with individual data. All data were managed in a MySQL database
with SPSS 18 for complex survey analysis. Descriptive analysis
and bivariate statistics were applied, followed by logistic regres-
sion analysis. Factor analysis was used to construct measurement
scales and for coding household economic level as categorized
in quintiles for multinomial logistic regression and in tertiles for
univariate analysis.
MEDICC Review, October 2012, Vol 14, No 4
28
Original Research
Peer Reviewed
Rates of respondents reporting high-risk behaviors were com-
pared among the three data-collection methods. For categorical
variables, we used the chi-square statistic to test for signifi cance
of proportions. ANOVA was used to compare number of sexual
partners reported with the three interview methods. Based on pre-
vious experience in Vietnam,[10,11] we anticipated greater differ-
ences in responses to sensitive topics across interview modes
in men, especially younger men, than in women. Therefore, we
hypothesized that there would be no signifi cant difference in
response rates or affi rmative answers to non-sensitive questions
across the three interview methods, and that response rates and
affi rmative answers to more sensitive questions related to sexual
attitudes and behaviors would increase with use of less personal
and more confi dential data collection methods. Specifi cally, affi r-
mative rates would be lower in PI and SA groups and highest with
ACASI.
For sensitive questions such as those related to risk behaviors,
we compared not only rates of reported behavior, but also rates
of question refusal. Finally, multinominal logistic regression was
applied to compare probability of answering “Yes” or refusing to
answer (response options “No answer” and “Don’t know”) versus
answering “No” for the question “Have you ever had sex with a
sex worker?” adjusted for all important respondent character-
istics: age, marital status, rural/urban location, socioeconomic
status and city. This analysis was done among male subjects
only, because women having sex with a sex worker is very rare
in Vietnam.
RESULTS
Sample comparability The fi nal successfully-interviewed sam-
ple consisted of 4049 individuals, 87.6% of the desired sample of
4620; 273 (5.9%) individuals selected were unreachable at time
of interviewer visit and 300 (6.5%) refused to participate. The rate
of successful interview was 85.5% for ACASI, 88.2% for SA and
89.2% for PI. There were nonsignifi cant differences in percent-
ages of unreachable individuals and refusals among the three
data-collection methods, with slightly higher percentages of both
for ACASI (Table 1).
The three randomized groups were comparable in distribution
of all attributes except sex; the proportion of women was slight-
ly higher in the ACASI group (57.4%) than in the other two (PI
53.4%, SA 54.1%, p <0.05). There were no signifi cant differ-
ences among groups for distribution of respondents’ mean age,
city of residence, urban or rural locality, age group, marital sta-
tus, household economic status or educational level. Mean age
was 30.1 years and most participants were married (62.5%)
(Table 2).
Comparison of responses to questions of differing sensi-
tivity Table 3 displays selected questions of differing sensitivity:
two non-sensitive questions and three more sensitive questions
regarding sexual and risk behaviors: premarital sex, sex with a
sex worker or injection drug use. Affi rmative-answer and refusal-
rate patterns were very similar across the three study groups for
the non-sensitive questions. There was a signfi cant difference
between the ACASI group and the other two groups in affi rmative
responses to two sensitive questions on premarital sex (ACASI
20.4% versus SA 11.1%, PI 11.4%) and drug use (ACASI 2% ver-
sus SA 0.5%, PI 0.4%). ACASI refusal rate for the question about
premarital sex was also signifi cantly lower than those of either SA
or PI (3.4 % versus 10.4% and 8%, respectively). Data are pre-
sented for both sexes combined, since there were no signifi cant
differences between them (Table 3).
Men and women responded similarly to non-sensitive questions
but men had higher affi rmative response rates than women to
questions about premarital sex and sex with recent casual part-
ners. In men, the ACASI group had the highest percentage of
affi rmative responses to the question about premarital sex (29%
versus 14% in SA and 17.3% in PI). In women, a similar pattern
was observed, but at lower rates (14% in ACASI, versus 8.7% in
Table 1: Interview success rate
Characteristics Data Collection Method
PI SA ACASI All
Total sample selected (N) 1540 1540 1540 4620
Successful interview
(n, %) 1374
(89.2%) 1359
(88.2%) 1316
(85.5%) 4049
(87.6%)
Unreachable sample
(n, %) 80
(5.2%) 81
(5.3%) 110
(7.1%) 271
(5.9%)
Refusal
(n, %) 86
(5.6%) 100
(6.5%) 114
(7.4%) 300
(6.5%)
PI: Personal interview SA: Self-administered paper-and-pencil interview
ACASI: Audio computer-assisted self interview
Table 2: Respondent characteristics
Characteristics Data Collection Method
PI SA ACASI All
Total sample interviewed (N) 1374 1359 1316 4049
Mean age (years) 30.3 30.2 29.6 30.1
Cities
Ha Noi (n=1304) 31.1% 32.4% 33.1% 32.2%
Da Nang (n=1378) 34.4% 33.8% 33.9% 34.0%
Can Tho (n=1367) 34.5% 33.8% 33.0% 33.8%
Location
Urban (n=2003) 31.1% 32.4% 33.1% 32.2%
Rural (n=2046) 34.4% 33.8% 33.9% 34.0%
Age group
15–19 years (n=912) 21.1% 21.9% 24.7% 22.5
20–29 years (n=1073) 26.2% 26.3% 27.1% 26.5
30–39 years (n=1012) 25.5% 24.4% 25.1% 25.0
40–49 years (n=1052) 26.5% 26.3% 23.2% 25.3
Sexa
Male (n=1804) 45.9% 45.1% 42.6% 44.6%
Female (n=2224) 53.4% 54.1% 57.4% 54.9%
No information (n=21) 0.7% 0.8% 0.0% 0.4%
Marital status
Married (n=2508) 63.9% 63.1% 60.3% 62.5%
Unmarried (n=1541) 36.1% 36.9% 39.7% 37.5%
Household SESb
Low (n=1526) 35.6% 32.8% 37.3% 37.7%
Average (n=1518) 39.8% 38.8% 40.7% 37.5%
High (n=622) 16.1% 19.7% 15.1% 15.4%
No information (n=383) 8.5% 8.7% 6.9% 9.5%
Educational level completed
Less than high school (n=1639) 42.3% 40.0% 39.1% 40.5%
High school (n=1280) 30.9% 30.2% 33.8% 31.6%
College and higher (n=1044) 24.7% 25.9% 26.8% 25.8%
No information (n=86) 2.2% 3.8% 0.3% 2.1%
PI: Personal interview SA: Self-administered paper-and-pencil interview
ACASI: Audio computer-assisted self interview
a p <0.05 for ACASI vs. other two methods
b Household socioeconomic status (SES) score was developed based on main
valuable household assets; the fi nal scale was tested for reliability (Cronbach’s
Alpha = 0.81), then categorized into tertiles.
29
MEDICC Review, October 2012, Vol 14, No 4 Peer Reviewed
Original Research
SA and 6.4% in PI, respectively). The ACASI group also showed
signifi cantly higher (p <0.05) affi rmative response rates than
the other two groups in both rural and urban settings. In urban
districts, 22.3% of ACASI respondents reported having had pre-
marital sex (versus 13.7% and 11.3% of SA and PI respondents,
respectively). In rural areas, percentages in ACASI, SA and PI
groups were 19%, 8.6% and 11.4% respectively (Figure 1).
Sexual behavior Respondents in the three groups were com-
pared by mean reported number of sexual partners over the pre-
vious 12 months and mean number of lifetime sexual partners
(among the sexually active sample) in different subgroups (mar-
ried and unmarried; men and women; urban and rural). Mean
number of lifetime partners was similar in all subgroups, but mean
number of reported sexual partners in the previous 12 months in
the married ACASI group was 1.34 (95% CI 1.21–1.47) versus
1.04 (95% CI 1.02–1.06) in SA and 1.16 (95% CI 1.10–1.21) in
the PI group, respectively. Figure 1 shows the breakdown for the
latter question by sex, marital status and urban/rural locality. In
the married sample, the mean number of sexual partners reported
by the ACASI group was signifi cantly higher than reported in the
other two groups; the same held true for both the urban and rural
sample, but not for unmarried respondents nor for women.
A multinominal logistic regression model was constructed to pre-
dict likelihood of reporting having sex with sex workers among the
sexually active male sample (Table 4). Adjusting for marital status,
age, rural/urban, city and socioeconomic variables included in the
model, a male subject in the ACASI group was 2.8 times more
likely to answer “yes” to the question “Have you ever had sex with
a sex worker?” than was a male subject in the PI group (OR 2.8,
CI 1.4–5.6). Male subjects in the SA group were also more likely
to answer “yes” to this question compared to their PI counterparts
(OR 2.3, CI 1.2–4.6). Probability of refusal was much lower in the
ACASI group than in the interview group (OR 0.3, CI 0.2–0.5).
The multinominal model also revealed marital status, age and
city of residence to be related to sexually active men’s probabil-
ity of refusal to answer the same question, with odds as follows:
unmarried men, OR 50.4 (CI 32.9–77.1); men aged 15 to 19 years
versus men aged 40 to 49 years, OR 6.4 (CI 3.3–12.5); men in
Da Nang versus men in Can Tho, OR 1.8 (CI 1.2–2.8); rural men
versus urban, OR 1.9 (CI 1.3–2.7).
DISCUSSION
This survey aimed to extract lessons and insights for a later
broader study. Previous research worldwide and in Vietnam found
rates of successful interviews higher using ACASI than either PI
or SA.[4,10,17] Le et al. also reported that response rates were
higher in younger respondents when ACASI was applied. In 2001,
Bui’s population survey in Quang Ninh using a tape-recorded
questionnaire elicited a response rate of 97% for persons aged
Table 3: Comparison of responsesa to selected questions of
differing sensitivity
Question
Response
Yes (%) Refusal (%)
ACASI
(N=1540) SA
(1540) PI
(1540) ACASI
(1540) SA
(1540) PI
(1540)
Watch TV
almost daily 33.2 33.3 33.5 0.1 0.3 0.0
Read
newspapers
almost daily 32.3 34.3 33.3 0.1 0.2 0.0
Ever had
premarital sex 20.4b11.1 11.4 3.4b10.4 8.0
Ever used
drugs 2.0b0.5 0.4 0.5 1.9 0.4
Ever had sex
with a sex
worker 4.3 5.5 2.3 0.1 2.2 0.9
ACASI: Audio computer-assisted self interview; SA: Self-administered paper-and-
pencil interview; PI: Personal interview
a Both sexes combined, since differences between them were nonsignifi cant
b p <0.05 ACASI vs. other two methods
Table 4: Multinominal logistic regression model for affi rmative
response (Yes) and refusal by sexually active Vietnamese men to
question Have you ever had sex with a sex worker? (N=1452)
Variable Response
Yes Refusal
OR (95% CI) OR (95% CI)
Socioeconomic status
Lowest vs. highest quintile 0.5 (0.2–1.3) 1.1 (0.6–2.0)
Second lowest vs. highest quintile 0.5 (0.2–1.2) 0.8 (0.5–1.5)
Middle vs. highest quintile 0.8 (0.4–1.7) 0.9 (0.5–1.6)
Second highest vs. highest quintile 0.6 (0.3–1.3) 0.6 (0.4–1.1)
Marital status
Single vs. ever married 1.4 (0.6–3.1) 50.4 (32.9–77.1)
Age group (years)
15–19 vs. 40–49 1.1 (0.3–4.6) 6.4 (3.3–12.5)
20–39 vs. 40–49 0.9 (0.5–1.6) 1.0 (0.6–1.5)
Interview method
ACASI vs. PI 2.8 (1.4–5.6)a0.3 (0.2–0.5)b
SA vs. PI 2.3 (1.2–4.6)a1.4 (0.9–2.1)
Location
Ha Noi vs. Can Tho 1.0 (0.5–1.8) 1.6 (1.0–2.4)
Da Nang vs. CanTho 0.6 (0.3–1.2) 1.8 (1.2–2.8)a
Rural/Urban
Rural vs. urban 1.9 (1.1–3.4)a1.9 (1.3–2.7)a
ap <0.05
bp <0.01
Figure 1: Interview mode and mean number of sexual partners in
previous 12 months by marital status, sex and rural/urban locality
2.5
2.0
1.5
1.0
0.5
0.0
ACASI
Married
1.3a
1.0
1.2
2.32.1
1.6
1.9a
1.2
1.4
1.11.0 1.1
1.5a
1.21.2
1.4a
1.01.1
Male UrbanUnmarried Female Rural
SA PI
ap <0.05 ACASI vs. other two methods
MEDICC Review, October 2012, Vol 14, No 4
30
Original Research
Peer Reviewed
15 to 45 years.[18] A more recent survey in Hai Phong in 2008
(using a CD player to play prerecorded questions) with a sample
aged 18 to 29 years reported a response rate of 98%.[19] Howev-
er, other national studies in young populations using non-ACASI
methods—SAVY1 and SAVY2—reported interview success rates
of only 85%.[20]
The overall success rate of about 88% in this study was there-
fore very good. The interview success rate for the ACASI group
was 86%, slightly but not signifi cantly lower than the rates for
other methods; and ACASI also resulted in similar refusal rates.
Given that other variables were distributed similarly in the three
interview modes, the difference in proportion of male and female
respondents was probably chance. Also, there were no statistical-
ly signifi cant differences among the three methods with regard to
non-sensitive questions, suggesting that for routine factual ques-
tions, ACASI has no particular advantage over SA and PI, con-
sistent with previous fi ndings in Vietnam and elsewhere.[5,11,21]
The fact that the SA sample tended to have the highest refusal
rates on sensitive questions raises issues about the applicability
of SA compared to the other two methods. It is likely that people
felt more comfortable and less “guilty” skipping questions in SA
mode than in the other two methods, as there is no pressure for
them to fi ll in the box when they handle the forms on their own.
In contrast, a clear pattern emerged revealing that when asked
by ACASI, respondents are less likely to refuse. Responses to
selected questions at different levels of sensitivity are intriguing in
that the ACASI group showed slightly lower affi rmative response
rates compared to PI in most non-sensitive topics, but higher
rates in sensitive ones. Responses for sensitive issues did not
differ between urban and rural settings; although rates of reported
premarital sex were slightly higher in urban respondents than in
rural. They were at least eight percentage points higher in the
ACASI group in both settings. No previous study in Vietnam was
able to look at this technique in rural samples,[10] so this fi nding
is helpful and supports the idea of using ACASI in both rural and
urban regions in future research.
Drug use is a highly sensitive behavioral question and in this
respect, our fi ndings revealed a clear advantage of ACASI, with
consistently higher affi rmative response rates than SA and PI for
both sexes and all locations. Percentages of reported premarital
sexual relationships were also signifi cantly higher in the ACASI
group (20.4%); the same trend has been reported previously but
the difference found here—almost twofold—was even greater
than seen in previous studies.[10]
A similar pattern was found regarding sexual relationships. Inter-
estingly, as hypothesized, male subjects consistently showed
a trend to greater response differences with ACASI than their
female counterparts. However, due to small sample size in the
female sexually active group, only the mean number of men’s
sexual partners in the last 12 months was found signifi cantly high-
er in the ACASI group. In other words, for men, ACASI seems to
be more appropriate and yield more reliable affi rmative responses
for such sensitive topics. This is consistent with a previous ACASI
trial in Vietnam, which found similar high response rates on sen-
sitive questions about sexual risk behaviors among male youth
in Vietnam, but lower response rates in young women.[10] This
pattern is, however, opposite to that found in several studies in
Africa, in which young women showed higher responsiveness
to ACASI.[5,6,22] Other factors, such as differing levels of com-
fort with technology, could also contribute to the apparent lack of
advantage for female respondents seen for ACASI in this study.
Determining whether it is an artifact of study power or a true dif-
ference would require a study with larger sample size for women.
The fi ndings from the multinominal logistic regression model again
affi rmed the advantage of using ACASI compared to SA and PI
methods in the specifi c sensitive question of having sex with sex
workers. Data also suggest that those in the SA group were sig-
nifi cantly more likely to “skip” such tough questions. This could be
a threat to the validity of the fi ndings in the SA group, where the
refusal rate is much higher than in the ACASI and PI groups. The
other signifi cant results for independent variables in the multinomial
model were also culturally understandable, as male youth—espe-
cially if married—may be less comfortable than more senior men
speaking openly about such a risk behavior. Also, social norms and
pressures in more urbanized settings may make men more likely
to choose the option appearing more neutral and less provoca-
tive, i.e., selecting the “no information response”. This may help to
explain why men in Ha Noi, Da Nang (both more urbanized than
Can Tho) were more likely to refuse than their counterparts in Can
Tho. However, no previous study in Vietnam has reported on this
issue, so we have no basis for comparison.
There are a number of limitations in a study of this kind. First,
the sample is drawn from only three cities, with no pretensions to
national representation. Thus, the fi ndings cannot be generalized
to Vietnam as a whole. Second, low prevalence of some sexual
behaviors limits possibilities both for comparison and data dis-
aggregation, such as between married and unmarried samples.
Third, the study was not able to differentiate honesty from accura-
cy, although certainly one could argue that honesty is more likely
to produce greater accuracy than dishonesty.
In any case, there is always the possibility that some respon-
dents—especially young men—may have exaggerated their sex-
ual life. Or, on the other hand, some respondents may still have
been suffi ciently uncomfortable in the home setting, and thus
under-reported high-risk behaviors. These issues have been dis-
cussed by other researchers previously as a source of information
bias, regardless of interview method.[23]
Another limitation may be low literacy and lack of familiarity with
a computer keyboard. Such issues have been reported and dis-
cussed in feasibility studies of ACASI in countries such as Peru,
China, India and Russia.[24] In this study, however, we purposely
selected three cities with rather high literacy levels. More impor-
tantly, low refusal rates in ACASI respondents support the idea
that ACASI was not too diffi cult for this sample. Some authors
have suggested that a more user-friendly version of ACASI might
better facilitate its use, irrespective of educational level.[23]
Another previous study in adolescents in Ha Noi used an addition-
al keypad attached to the laptop with a colored sticker for answer
entry, allowing illiterate respondents to answer more easily.[10]
However, such adaptations are more costly and complicated.
Although this is not a limitation of the study per se, one might argue
that costs may present a barrier for wider use of ACASI. It is cer-
tainly an issue that research teams have to consider carefully, but
in our experience, use of laptops for interviews can offset other
costs. For example, data entry costs are reduced because respon-
31
MEDICC Review, October 2012, Vol 14, No 4 Peer Reviewed
Original Research
dents directly key in their answers. Also, laptop prices have been
decreasing rapidly, and we can certainly use these laptops (and
installed software) for similar projects in the future, at least for a
few more years. Therefore, despite some limitations, we consider
ACASI a promising alternative in studies to assess risk behavior in
Vietnam. Further studies targeting male respondents in the area of
HIV/AIDS (such as surveys of men who have sex with men) should
consider this application to obtain more honest answers, which we
consider more likely to produce accurate information.
CONCLUSIONS
Program implementers in HIV-related projects as well as research-
ers and policymakers have had a legitimate concern that sensitive
issues such as unsafe sexual practices and other risk behaviors
tend to be under-reported in surveys and assessments, leading to
development of interventions based on skewed and faulty infor-
mation. This study confi rmed the applicability and advantages of
ACASI compared to traditional interview modes in improving item
response rates and responses to sensitive questions, especially
in male respondents (in both rural and urban settings). Although
ACASI still has not been demonstrated to have advantages for
use with female respondents in the Vietnamese context, it is a
promising methodology that may help increase honesty, leading
to greater accuracy of future data collection on sensitive topics.
ACKNOWLEDGMENTS
This study was supported by a PEPFAR grant to the Hanoi School
of Public Health under the project Partnering with Hanoi School
of Public Health to Enhance Public Health Capacity for HIV Pre-
vention and Care Activities in Vietnam. The authors would like
to thank the Hanoi School of Public Health and PEPFAR/CDC
Vietnam for their support.
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THE AUTHORS
Linh Cu Le (Corresponding author: lcl@hsph.
edu.vn), physician with a master’s degree in
applied development and a doctorate in public
health. Chair, department of demography, Hanoi
School of Public Health, Vietnam.
Lan T.H. Vu, physician with a doctorate in epi-
demiology. Chair, department of epidemiology
and biostatistics, Hanoi School of Public Health,
Vietnam.
Submitted: December 31, 2011
Approved for publication: August 22, 2012
Disclosures: None
