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Content uploaded by Maria Van Rompay
Author content
All content in this area was uploaded by Maria Van Rompay
Content may be subject to copyright.
Original Contributions
Trends in Alternative Medicine Use
in the United States, 1990-1997
Results of a Follow-up National Survey
David M. Eisenberg, MD; Roger B. Davis, ScD; Susan L. Ettner, PhD; Scott Appel, MS;
Sonja Wilkey; Maria Van Rompay; Ronald C. Kessler, PhD
Context.—A priornationalsurveydocumentedthehighprevalenceandcostsof
alternative medicine use in the United States in 1990.
Objective.—TodocumenttrendsinalternativemedicineuseintheUnitedStates
between 1990 and 1997.
Design.—Nationallyrepresentative randomhousehold telephonesurveys using
comparable key questions were conductedin 1991 and1997 measuring utilization
in 1990 and 1997, respectively.
Participants.—A total of 1539 adults in 1991 and 2055 in 1997.
Main Outcomes Measures.—Prevalence, estimated costs, and disclosure of
alternative therapies to physicians.
Results.—Use of at least 1 of 16 alternative therapies during the previous year
increased from 33.8% in 1990 to 42.1% in 1997 (
P
#.001). The therapies increas-
ing the most included herbal medicine, massage, megavitamins, self-help groups,
folkremedies,energy healing,andhomeopathy. Theprobability of usersvisiting an
alternativemedicine practitioner increasedfrom 36.3%to 46.3%(
P
= .002).In both
surveys alternative therapies were used most frequently for chronic conditions, in-
cluding back problems,anxiety, depression, and headaches.There was no signifi-
cant change in disclosure rates between the 2 survey years; 39.8% of alternative
therapies were disclosed to physicians in 1990 vs 38.5% in 1997. The percentage
of users payingentirely out-of-pocket for services providedby alternative medicine
practitioners did notchange significantly between 1990(64.0%) and 1997 (58.3%)
(
P
=.36). Extrapolations to the US population suggest a 47.3% increase in total
visits to alternative medicine practitioners, from 427 million in 1990 to 629 million
in 1997, thereby exceeding total visits to all US primary care physicians. An esti-
mated 15 million adults in 1997 took prescription medications concurrently with
herbal remedies and/or high-dose vitamins (18.4% of all prescription users). Esti-
matedexpendituresforalternativemedicineprofessionalservicesincreased45.2%
between1990and1997andwereconservativelyestimatedat$21.2billionin1997,
with at least $12.2 billion paid out-of-pocket. This exceeds the 1997 out-of-pocket
expenditures for all US hospitalizations. Total 1997 out-of-pocket expenditures re-
lating to alternative therapies were conservatively estimated at $27.0 billion, which
is comparable with the projected 1997 out-of-pocket expenditures for all US phy-
sician services.
Conclusions.—Alternative medicine use and expenditures increased substan-
tially between 1990 and 1997, attributable primarily to an increase in the proportion
of the population seeking alternative therapies, rather than increased visits per
patient.
JAMA. 1998;280:1569-1575
From the Center for Alternative Medicine Research
and Education, Department of Medicine, Beth Israel
Deaconess Medical Center (Drs Eisenberg and Davis,
Mr Appel, and Mss Wilkey and Van Rompay), and the
Department of Health Care Policy, Harvard Medical
School (Drs Ettner and Kessler), Boston, Mass.
Reprints: David M. Eisenberg, MD, Center for Alter-
native Medicine Research and Education, Beth Israel
Deaconess Medical Center, 330 Brookline Ave, Boston,
MA 02215.
ALTERNATIVE medical therapies,
functionally defined as interventions
neither taught widely in medical schools
nor generally available in US hospitals,
1
have attracted increased national atten-
tion from the media, the medical com-
munity, governmental agencies, and the
public. A 1990 national survey of alter-
native medicine prevalence, costs, and
patterns of use
1
demonstrated that al-
ternative medicine has a substantial
presence in the US health care system.
Data from a survey in 1994
2
and a public
opinion poll in 1997
3
confirmed the ex-
tensive use of alternative medical thera-
pies in the United States. An increasing
number of US insurers and managed
care organizations now offer alternative
medicine programs and benefits.
4
The
majority of US medical schools now of-
fer courses on alternative medicine.
5
National surveys performed outside
the United States suggest that alterna-
tive medicine is popular throughout the
industrialized world.
6
The percentage of
the population who used alternative
therapies during theprior 12months has
been estimated to be 10% in Denmark
(1987),
7
33% in Finland (1982),
8
and 49%
in Australia (1993).
9
Public opinion polls
and consumers’association surveyssug-
gest high prevalence rates throughout
Europe and the United Kingdom.
10-13
The percentage of the Canadian popula-
tionwho saw analternativetherapyprac-
titioner during the previous 12 months
has been estimated at 15% (1995).
14
The
wide range of utilization rates can be
explained, in part, by the disparity in
definitions of alternative therapy and the
selection of therapies assessed.
The presumption is that alternative
medicine use in the United States has
increased at a considerable pace in re-
cent years.The purpose ofthis follow-up
national survey was to investigate this
presumption and document trends in al-
ternative medicine prevalence, costs,
disclosure of use to physicians, and cor-
relates of use since 1990.
METHODS
Sample
We conducted parallel nationally rep-
resentative telephone surveys in 1991
and 1997. Survey methods were ap-
proved by the Beth Israel Deaconess In-
stitutional Review Board, Boston, Mass.
JAMA, November 11, 1998—Vol 280, No. 18 Trends in Alternative Medicine Use in the United States—Eisenberg et al 1569
©1998 American Medical Association. All rights reserved.
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Both surveys used random-digit dialing
to select households and random selec-
tionof 1 householdresident, aged 18years
or older, as the respondent. Eligibility
was limited to English speakers in whom
cognitive or physical impairment did not
prevent completion of the interview. We
asked respondents about their use of al-
ternative therapies during the prior 12
months. We consider the results of the
1991 survey, fielded between January
and March of that year, representative of
1990, and the results of the 1997 survey,
fielded between November 1997 and
February 1998, representative of 1997.
The sampling scheme was designed
with a target sample of 1500 in 1990 and
2000 in 1997. The latter sample size was
chosen to provide power in excess of 80%
to detect an increase from 34% to 39% in
theproportion ofadults whoused at least
1 form of alternative therapy during the
prior 12 months. The actual numbers of
completed interviews were 1539 in 1990
(67% response rate) and 2055 in 1997
(60% weighted response rate). A secular
trend in lower survey response required
us to offer a $20 financial incentive for
participation in the 1997 survey to main-
tain a response rate near the one
achieved in 1990. No financial incentive
was used in the 1990 survey.
The data in each survey were sepa-
rately weighted to adjust for geographic
variation in cooperation (eg, by region of
countryand urbanicity) andfor household
variationin probability ofselection (ie, the
inverse relationship between size of
household and probability of selection be-
cause only 1 interview was completed in
each sample household). The data were
then weighted in parallel on sociodemo-
graphic variables to adjust for aggregate
discrepancies between the sample distri-
butions and population distributions pro-
vided by the US Census Bureau. This last
stage of weighting was based on the 1997
Current Population Survey data
15
and
was done in parallel across the 2 surveys
to remove any between-survey discrep-
ancies of weighted sociodemographic dis-
tributions.
Of the initial sample of 9750 telephone
numbers in 1997, 26% were nonworking,
17% were not assigned to households, and
9% were unavailable (ie, despite 6 at-
tempted follow-up contacts). We de-
clared 481 households ineligible because
respondents did not speak English or
because of cognitive or physical incapac-
ity. Among the remaining 4167 eligible
respondents, 1720 (41.3%) completed the
interview on initial request. Attempts
were then made to convert a random sub-
sample of 1066 refusers by offering them
an increased stipend ($50). A total of 335
(31.4%) of the 1066 contacted were con-
verted in this manner. Extrapolating this
conversion rate to all of the refusers and
weighting the data for the undersam-
pling of initial refusers, we obtained a 60%
(41.3% + [31.4% × (100% − 41.3%)])
weighted overall response rate among eli-
gible respondents.
Interview
In both years, the interview was pre-
sented as a survey conducted about the
health care practices of Americans by
investigators from Harvard Medical
School. No mention was made of alter-
native or complementary therapies. The
substantive questions began by asking
about perceived health, health worries,
days spent in bed, and functional impair-
ment due to health problems. We then
asked respondents about their interac-
tions with a medical doctor, defined as “a
medical doctor (MD) or a doctor of os-
teopathic medicine (DO), not a chiro-
practoror other nonmedical doctor.” The
term medical doctor was used through-
out the remainder of the interview.
To document trends we explored the
following: (1) Respondents in both sur-
veys were presented with a list of com-
mon medical conditions and asked if they
had experienced each of these conditions
during the previous 12 months. (2) Re-
spondents who reported more than 3
conditions were asked to identify their 3
most bothersome or serious medical con-
ditions and were then asked about seeing
a medical doctor for these principal medi-
cal conditions and about the perceived
quality of these interactions. (3) Respon-
dents were asked about their lifetime and
past12-month use of 16 alternativethera-
pies and whether each of these therapies
was used for each of the principal medical
conditions. The 1997 survey also asked
about use for a representative sample of
other medical conditions and expanded
the list of therapies beyond the original
16 assessed in 1990. (4) We distinguished
between use under the supervision of a
practitioner of alternative therapy and
use without such supervision. Respon-
dents who reported supervised use were
asked about their number of visits in the
past 12 months to practitioners of each
therapy.(5) All usersof alternative thera-
pies in 1997 who acknowledged seeing a
medical doctor during the past year were
then asked if they had discussed their use
ofeach therapy witha medical doctor and,
if not, why not.
Prior use of 16 targeted therapies was
explored using a computer-assisted in-
terview transcript, which included the
following clarifications in both 1990 and
1997: When asking about high-dose vi-
tamin or megavitamin therapies, inter-
viewers made clear that the survey
sought information on vitamins not in-
cluding a daily vitamin or vitamin pre-
scribed by a doctor. Prayer or spiritual
healing by others was asked about sepa-
rately from prayer or spiritual practice
for individual health concern. Commer-
cial diet programs were described as
“the kind you have to pay for, but not
including trying to lose or gain weight on
your own.” A lifestyle diet included ex-
amples like vegetarianism or macrobiot-
ics. Questions regarding energy healing
included examples of magnets, energy-
emitting machines, or the “laying on of
hands,” and use of relaxation techniques
was explained using the examples of
meditation or the relaxation response.
The remaining 9 therapies were asked
about without interviewer clarification.
The 1997 survey was longer (average,
30 minutes) than the 1990 survey (aver-
age, 25 minutes) because we sought to
explore a number of areas in more depth.
All the important questions in the 1990
survey were repeated in 1997. These
replicated questions are the focus of the
current report. One major change in the
1997 survey involved replicated ques-
tions: respondents who reported using
more than 3 alternative therapies were
asked in-depth questions (eg, use of a
practitioner of alternative therapies,
number of visits, out-of-pocket ex-
penses, reasons for use) for all such
therapies in 1990 but only for a random
sample of 3 such therapies in 1997. This
was required because of expansion in
both the number of alternative thera-
pies we assessed in 1997 and questions
about each therapy. The 1997 data were
weighted to adjust for this sampling in
making comparisons with the 1990 data.
Insurance Coverage
For each therapy for which respon-
dents said they used services of an alter-
native medicine practitioner, we asked
whether insurance helped pay for any of
the costs of the therapy and whether the
respondent paid any of the costs out-of-
pocket. Based on the answers to these
questions, we calculated the proportion of
users of each therapy who had complete,
partial, or no insurance coverage for that
therapy. We also calculated the overall fre-
quency of insurance coverage by weight-
ing the insurance frequencies within each
therapy by the proportion of all user thera-
pies accounted for by that therapy.
Construction of Cost Measures
The total cost of visits to alternative
medicine practitioners was calculated by
multiplying the number of visits for each
therapy by a per-visit price and adding
the prices of the following therapies: re-
laxation techniques, herbal medicine,
massage therapy, chiropractic care,
megavitamins, self-help groups, imag-
ery techniques, commercial diet, folk rem-
1570 JAMA, November 11, 1998—Vol 280, No. 18 Trends in Alternative Medicine Use in the United States—Eisenberg et al
©1998 American Medical Association. All rights reserved.
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edies, lifestyle diet, energy healing, ho-
meopathy, hypnosis, biofeedback, and
acupuncture. Out-of-pocket costs were
constructed for each therapy by multi-
plying each user’s visits by the full price
of the visit if the user had no insurance
coverage, by 0.2 if the user had partial
insurance coverage, and by zero if insur-
ance paid the full price of the visit. The
assumption of a 20% coinsurance rate
among users with partial insurance cov-
erage should yield a conservative esti-
mate of out-of-pocket costs, because it ig-
nores deductibles and benefit caps and
assumes that insurance benefits for al-
ternative therapy are similar to medical
coverage.
We calculated costs based on per-visit
prices chosen from typical prices paid for
such services by private insurers using a
Resource-Based Relative Value Scale
(RBRVS)
16
system in selected states. We
then recalculated costs using a second set
of prices chosen partly to reflect empirical
dataon theout-of-pocket costspaid by the
respondents, but primarily to represent
conservative estimates of the per-visit
cost of alternative therapies. Total costs
based on this second set of prices should
represent a lower bound on true expen-
ditures.
Out-of-pocket costs of herbs, megavi-
tamin supplements, and commercial diet
products were calculated by multiplying
the total population of users by the aver-
age out-of-pocket expenditures reported
by respondents who used each of these
products. In 1997, each respondent who
used an alternative therapy was also
asked, “Did you spend any additional
money on things like books, classes,
equipment, or any other items related to
[the alternative therapy] in the past 12
months?” Out-of-pocket expenditures on
these other items were calculated follow-
ing the same procedures used for herbs,
megavitamins,and commercial dietprod-
ucts. Out-of-pocket expenditures on
herbs, megavitamins, commercial diet
products, and related items were based
on actual dollar amounts reported, so
changes between 1990 and 1997 include
inflation. To isolate the increase in the
cost of practitioner visits between 1990
and 1997 solely because of the increase in
the use of alternative therapies, we cal-
culated1990 practitioner costs using 1997
prices. The differences between the 1990
and 1997 costs of practitioner services re-
ported are understated because they do
not take into account inflation, estimated
at 44% by the medical component of the
Consumer Price Index.
17
Statistical Analysis
Analyses reported herein consist of
computation of prevalence and mean es-
timates and comparisons of these esti-
mates through the years. As the data in
both surveys are weighted, the Taylor
series method was used to compute sig-
nificance tests using SUDAAN soft-
ware.
18
x
2
Tests of independence were
used for comparing proportions, while t
tests were used for continuous mea-
sures. Extrapolations of survey esti-
mates to the total population were based
on the assumption that there were 180
million adults living in the US household
population in 1990 and 198 million in
1997.
15
RESULTS
Characteristics of Respondents
The characteristics of the subjects we
interviewed are shown in Table 1. The
sociodemographic characteristics of the
survey sample are similar to the popu-
lation distributions published by the US
Bureau of the Census.
15
Patterns of Use
Use of alternative therapies in 1997
was not confined to any narrow segment
of society. Rates of use ranged from 32%
to 54% in the wide range of sociodemo-
graphic groups examined. Use was more
common among women (48.9%) than
men (37.8%) (P = .001) and less common
among African Americans (33.1%) than
members of other racial groups (44.5%)
(P = .004). People aged 35 to 49 years re-
ported higher rates of use (50.1%) than
people either older (39.1%) (P = .001) or
younger (41.8%) (P = .003). Use was
higher among those who had some col-
lege education (50.6%) than with no col-
lege education (36.4%) (P = .001) and
more common among people with annual
incomes above $50 000 (48.1%) than with
lower incomes (42.6%) (P = .03). Use was
more common among those in the West
(50.1%) than elsewhere in the United
States (42.1%) (P = .004). With the ex-
ception of observed sex differences in
1997, these patterns are consistent with
those identified in 1990.
Population prevalence estimates of al-
ternative medicine use in 1990 and 1997
are shown in Table 2. The 1990 survey
estimated that 33.8% of the US adult
population (60 million people) used at
least 1 of the 16 alternative therapies
listed, while the 1997 survey estimated
that this proportion increased signifi-
cantly to 42.1% (83 million people). A
comparison of specific therapies in the
first column shows increases in 15 of the
16 therapies; 10 of these were statisti-
cally significant (P # .05). The largest
increases were in the use of herbal medi-
cine, massage, megavitamins, self-help
groups, folk remedies, energy healing,
and homeopathy. Summing Table 2 (first
column) data shows a 65% increase in
total number of therapies used, from 577
therapies per 1000 population in 1990 to
953 per 1000 in 1997.
Several categories of alternative
therapy warrant clarification about the
actual modalities used. Three quarters of
respondents who acknowledged use of
relaxation techniques said they used
meditation. Among those who reported
usingenergy healing, the most frequently
cited technique involved the use of mag-
nets. Other modalities common to this
category included Therapeutic Touch,
Reiki, and energy healing by religious
groups. The use of self-prayer, in contrast
to spiritual or energy healing performed
by others, was investigated in terms of
prevalence of use but not in terms of
costs, referral patterns, or insurance re-
imbursement. All analyses in this article
exclude data involving self-prayer.
Table 2 (second column) shows that a
significantly higher proportion of alter-
native therapy users saw an alternative
medicine practitioner in 1997 (46.3%,
equivalent to 39 million people) than in
1990 (36.3%, equivalent to 22 million
people). Of the 15 therapies for which
the question was asked, the proportion
of users who saw a practitioner in-
creased for 11. However, even in 1997
there were only 5 therapies in which
a majority of users consulted a practi-
Table 1.—Characteristics of the 1997 (N = 2055)
and 1990 (N = 1539) Subjects Interviewed Com-
pared With the US Population*
Characteristic
1997
Survey, %
1997 US
Bureau of the
Census,
17
%
1990
Survey, %
Sex
Female 52 52 48
Male 48 48 52
Age, y
18-24 10 13 16
25-34 22 20 23
35-49 33 32 27
$50 35 35 34
Race/ethnicity
White 77 73 82
African American 8 12 9
Hispanic 10 11 6
Asian 1 4 1
Other 4 1 2
Education
,High school 14 18 24
High school
graduate
37 34 35
College or more 49 48 40
Annual income, $
,20000 27 33 30
20000-49999 45 41 53
$50000 27 26 18
Region
Northeast 21 19 22
North central 24 24 32
South 35 35 26
West 20 22 19
*Duetorounding,percentages donotalways total100.
JAMA, November 11, 1998—Vol 280, No. 18 Trends in Alternative Medicine Use in the United States—Eisenberg et al 1571
©1998 American Medical Association. All rights reserved.
Downloaded From: http://jama.jamanetwork.com/ by Tufts Univ. Hirsh Health Sciences Library, Maria Van Rompay on 11/08/2014
tioner: massage, chiropractic, hypnosis,
biofeedback, and acupuncture. Unsuper-
viseduse (ie, a form of expanded self-care)
remains the usual method of use for all
other alternative therapies.
Table 2 (third column) reveals no con-
sistent change in the average number of
visits among respondents who consulted
practitioners of alternative therapy be-
tween 1990 (19.2%) and 1997 (16.3%).
However, because of the increase in the
proportion of people using these thera-
pies, the total number of visits increased
substantially from 1990 to 1997. This
47.3% increase in total visits is largely
because of increases in visits for relax-
ation therapy, massage, chiropractic,
self-help, and energy healing. The visits
to practitioners of alternative therapy in
1997 exceeded the projected number of
visits to all primary care physicians in
the United States by an estimated 243
million(Figure 1).
19,20
Visitsto chiroprac-
tors and massage therapists accounted
for nearly half of all visits to practition-
ers of alternative therapies.
Prevalence estimates for selected ad-
ditional therapies assessed in 1997 but not
1990 include: aromatherapy (5.6%), neu-
ral therapy (1.7%), naturopathy (0.7%),
and chelation therapy (0.13%) (data not
shown). Comparisons of total visits and
costs for 1990 and 1997 were performed
without inclusion of these data. Preva-
lence estimates for the simultaneous use
of prescription medications with herbs,
with high-dose vitamins, or with both were
obtained. Among the 44% of adults who
said they regularly take prescription medi-
cations, nearly 1 (18.4%) in 5 reported the
concurrent use of at least 1 herbal prod-
uct, a high-dose vitamin, or both.
Table 3 summarizes results regarding
use of alternative therapies for the most
commonly reported principal medical
conditions in either survey. In each year,
a majority of respondents reported 1 or
more principal medical conditions. The
list of conditions was expanded in 1997
(37 conditions) compared with 1990 (24
conditions). Significant increases in the
proportion using alternative therapies
for principal condition(s) (second col-
umn) occurred for back problems, aller-
gies, arthritis, and digestive problems.
The highest condition-specific rates of
alternative therapy use in 1997 were for
neck (57.0%) and back (47.6%) problems.
The proportion of respondents with 1 or
more medical conditions who reported
use of an alternative therapy for at least
1 of those conditions increased signifi-
cantly from 22.9% in 1990 to 33.7% in
1997 (P#.001). The weighted condition-
specific proportion who saw an alterna-
tive medicine practitioner for a given
condition also increased significantly
from 6.8% in 1990 to 11.4% in 1997
(P#.001).
Table 3 also summarizes the probabil-
ity that individuals who saw a medical
doctor for a particular condition also used
an alternative therapy (fourth column) or
also saw a practitioner of alternative
therapy (fifth column) for that same con-
dition during the same year. A generally
increasing pattern of alternative medi-
cine use can be seen across the range of
conditions studied. In 1990, an estimated
1 (19.9%) in 5 individuals seeing a medical
doctor for a principal condition also used
an alternative therapy. This percentage
increased to nearly 1 (31.8%) in 3 in 1997
(P#.001). The percentage who saw a
medical doctor and also sought the ser-
vices of an alternative practitioner in-
creased significantly from 8.3% in 1990 to
13.7% in 1997 (P#.01). In both 1990 and
1997, chiropractic, relaxation techniques,
and massage therapy were among the al-
700
1997 1990
100
0
200
300
400
500
600
628
825
000
Total No. of Visits, in Millions
Visits to All
Primary
Care
Physicians
20
Visits to
Practitioners
of Alternative
Therapies
Visits to All
Primary
Care
Physicians
19
Visits to
Practitioners
of Alternative
Therapies
385
919
000
427
120
000
387
558
000
Figure1.—Trends in annualvisits to practitionersof
alternative therapies vs visits to primary care phy-
sicians,United States,1997vs 1990.Dataare from
the NationalAmbulatory Medical Care Survey from
1996
20
and 1990.
19
Table 2.—Comparison of Prevalence and Frequency of Use of Alternative Therapies Among Adult Respondents, 1997 vs 1990*
Type of Therapy
Used in Past
12 mo, %
Saw a
Practitioner
in Past
12 mo, %
Mean No. of
Visits per
User in Past
12 mo
No. of Visits per
1000 Population
Estimated Total
No. of Visits in 1997
(in Thousands)†
Total
Visits, %‡§1997 1990 1997 1990 1997 1990 1997 1990
Relaxation techniques 16.3¶ 13.1 15.3 9.0 20.9 18.6 521.2 219.3 103203 16.4
Herbal medicine 12.1
** 2.5 15.1 10.2 2.9 8.1 53.0 20.7 10491 1.7
Massage 11.1
** 6.9 61.6# 41.4 8.4 14.8 574.4 422.8 113723 18.1
Chiropractic 11.0 10.1 89.9** 71.1 9.8 12.6 969.1¶ 904.8 191886 30.5
Spiritual healing by others\ 7.0# 4.2 . . . 9.2 . . . 14.2 . . . 54.9 . . . . . .
Megavitamins 5.5
** 2.4 23.7 11.8 8.6 12.6 112.1 35.7 22196 3.5
Self-help group 4.8
** 2.3 44.4 38.3 18.9 20.5 402.8 180.6 79754 12.7
Imagery 4.5 4.2 23.1 15.1 11.0 14.2 114.3 90.1 22640 3.6
Commercial diet 4.4 3.9 43.2 24.0 7.3 20.7 138.8 193.8 27474 4.4
Folk remedies 4.2
** 0.2 6.2 0.0 1.0 . . . 2.6 . . . 516 0.1
Lifestyle diet 4.0 3.6 8.0 12.5 2.8 8.1 9.0 36.5 1774 0.3
Energy healing 3.8
** 1.3 26.3 32.2 20.2# 8.3 201.9¶ 34.7 39972 6.4
Homeopathy 3.4
** 0.7 16.5 31.7 1.6 6.1 9.0 13.5 1777 0.3
Hypnosis 1.2 0.9 62.7 51.8 2.8 2.6 21.1 12.1 4171 0.7
Biofeedback 1.0 1.0 54.3 20.8 3.6 6.4 19.5 13.3 3871 0.6
Acupuncture 1.0è¶ 0.4 87.6 91.3 3.1 38.4 27.2 140.2 5377 0.9
$1 of 16 alternative therapies 42.1
** 33.8 46.3# 36.3 16.3 19.2 3176.0 2373.0 628825 ...
SE 1.2 1.4 1.9 2.5 1.8 4.5 378.7 599.7 74997 . . .
Self-prayer\ 35.1
** 25.2 . . . . . . . . . . . . . . . . . . . . . . . .
*Percentages are of those who used that type of therapy. Ellipses indicate data not applicable.
†Estimate based on 1997 population estimate of 198 million.
‡Percentage of total visits of the 16 therapies (ie, excluding self-prayer).
§Because of rounding, percentages do not total 100.
\Respondents who received spiritual healing by others were not asked for details of visits in 1997, nor were those who used self-prayer in either year.
¶
P
#.05; #
P
#.01; **
P
#.001.
1572 JAMA, November 11, 1998—Vol 280, No. 18 Trends in Alternative Medicine Use in the United States—Eisenberg et al
©1998 American Medical Association. All rights reserved.
Downloaded From: http://jama.jamanetwork.com/ by Tufts Univ. Hirsh Health Sciences Library, Maria Van Rompay on 11/08/2014
ternative therapies used most commonly
to treat principal medical conditions.
As in 1990, 96% of 1997 respondents who
saw a practitioner of alternative therapy
for a principal condition also saw a medi-
cal doctor during the prior 12 months, and
only a minority of alternative therapies
used were discussed with a medical doc-
tor. Among the 618 respondents in 1997
who used 1 or more alternative therapies
and had a medical doctor, only 377 (38.5%)
of the 979 therapies used were discussed
with the respondent’s medical doctor. This
is not significantly different from the 353
(39.8%) of the 886 therapies discussed by
the comparable group of respondents
(n = 501) in the 1990 survey. Given that
most alternative therapy is used without
the supervision of an alternative practi-
tioner, a substantial portion of alterna-
tive therapy use for principal medical con-
ditions (46.0% in 1997 and 51.3% in 1990)
was done without input from either a
medical doctor or practitioner of alterna-
tive therapy.
Payment for Alternative Therapy
Data on insurance coverage of expen-
ditures for alternative therapy services
are shown in Table 4. The majority of
people who saw alternative therapy
practitioners paid all the costs out-of-
pocket in both 1990 (64.0%) and 1997
(58.3%). None of the changes in insur-
ance coverage between 1990 and 1997
were statistically significant, probably
due in part to small sample sizes.
Using conservative assumptions about
the fees charged by practitioners of
alternative therapies and assuming no
changes in visit prices, Americans spent
anestimated$14.6 billion onvisits to these
practitioners in 1990 and $21.2 billion in
1997 (Table 5). Using less conservative
(RVRBS) price figures, the amount spent
on services of practitioners of alternative
therapies was estimated at $22.6 billion in
1990 and $32.7 billion in 1997. Regardless
of which set of prices is used, total expen-
ditures for practitioners of alternative
therapies are estimated to have increased
by approximately 45% between 1990 and
1997 exclusive of inflation.
Estimated out-of-pocket expenditures
for high-dose vitamins increased from
$0.9 billion in 1990 to $3.3 billion in 1997.
Smallerincreases were observedfor com-
mercial diet products ($1.3 billion vs $1.7
billion). Unlike the 1990 survey, the 1997
survey included questions about expen-
ditures for herbal products ($5.1 billion)
and respondents’ alternative therapy–
specific books, classes, or equipment
($4.7 billion).
The estimated total out-of-pocket
component of the alternative medicine
market in 1997 is shown in Figure 2. Pro-
jected out-of-pocket expenditures for all
hospitalizations in 1997 in the United
States totaled $9.1 billion, while projected
out-of-pocket expenses for all US physi-
cian services in the same year were $29.3
billion.
21
This compares to a conserva-
tively estimated $12.2 billion in out-of-
pocket payments to alternative medicine
practitioners for the 15 therapies studied.
Adding the estimates of $5.1 billion for
herbal therapies, $3.3 billion for megavi-
tamins, $1.7 billion for diet products, and
$4.7 billion on alternative therapy–spe-
cific books, classes, and equipment, the
totalout-of-pocketexpenditures for alter-
native medicine are conservatively esti-
mated to be $27.0 billion. Using the aver-
age per-visit prices derived from an
RBRVS system
16
rather than our conser-
vative estimates (Table 5), the estimated
total out-of-pocket expense is approxi-
mately $34.4 billion, which is comparable
with the projected 1997 out-of-pocket ex-
penditures for all physician services.
21
These estimates exclude out-of-pocket
expenditures associated with therapies
unique to the 1997 survey (eg, naturopa-
thy, aromatherapy, neural therapy, and
chelation therapy).
COMMENT
The results of our study are limited by
the restriction of the sampling frame to
people who speak English and have tele-
phonesand bythe lowresponse rate. The
decrease in overall response rate from
67% in 1990 to 60% in 1997 is consistent
with secular trends for US telephone in-
terviews in recent years.
22
It is difficult
to know what, if any, bias was introduced
or whether trend estimates are biased
by the fact that financial incentives were
used in 1997 but not 1990. Furthermore,
we have no data on the accuracy of self-
Table 3.—Comparison of Use of Alternative Therapies for the Most Frequently Reported Principal Medical Conditions, 1997 vs 1990
Condition
Percentage
Reporting
Condition
Used
Alternative
Therapy for
Condition in
Past 12 mo, %
Saw Alternative
Practitioner for
Condition in
Past 12 mo, %
Saw Medical
Doctor and
Used Alternative
Therapy
for Condition in
Past 12 mo, %
Saw Medical
Doctor and
Alternative
Practitioner for
Condition in
Past 12 mo, %
Therapies Most
Commonly Used in 19971997 1990 1997 1990 1997 1990 1997 1990 1997 1990
Back problems 24.0# 19.9 47.6# 35.9 30.1# 19.5 58.8
** 36.1 39.1# 23.0 Chiropractic, massage
Allergies 20.7# 16.0 16.6# 8.7 4.2 3.3 28.0¶ 15.7 6.4 5.0 Herbal, relaxation
Fatigue
* 16.7 . . . 27.0 . . . 6.3 . . . 51.6 . . . 13.1 . . . Relaxation, massage
Arthritis 16.6 15.9 26.7¶ 17.5 10.0 7.6 38.5¶ 23.8 15.9 13.8 Relaxation, chiropractic
Headaches 12.9 13.2 32.2 26.5 13.3¶ 6.3 42.0 31.8 20.0 12.1 Relaxation, chiropractic
Neck problems
* 12.1 . . . 57.0 . . . 37.5 . . . 66.6 . . . 47.5 . . . Chiropractic, massage
High blood pressure 10.9 11.0 11.7 11.0 0.9 2.9 11.9 11.6 1.1 3.5 Megavitamins, relaxation
Sprains or strains 10.8 13.4 23.6 22.3 10.3 9.6 29.4 24.7 15.9 13.6 Chiropractic, relaxation
Insomnia 9.3# 13.6 26.4 20.4 7.6 4.0 48.4 19.8 13.3 10.9 Relaxation, herbal
Lung problems 8.7 7.3 13.2 8.8 2.5 0.5 17.9 11.1 3.4 0.6 Relaxation, spiritualhealing,
herbal
Skin problems 8.6 8.0 6.7 6.0 2.2 1.6 6.8 6.9 0.0 2.5 Imagery, energy healing
Digestive problems 8.2 10.1 27.3# 13.2 9.7¶ 3.6 34.1¶ 15.3 10.7 5.8 Relaxation, herbal
Depression† 5.6 8.4 40.9 20.2 15.6 7.0 40.9 35.2 26.9 14.0 Relaxation, spiritual healing
Anxiety‡ 5.5 9.5 42.7 27.9 11.6 6.5 42.7 45.4 21.0 10.4 Relaxation, spiritual healing
Weighted average across
all conditions§
. . . . . . 28.2
** 19.1 11.4** 6.8 31.8** 19.9 13.7# 8.3 . . .
People with $1 condition\ 77.8¶ 81.5 33.7
** 22.9 15.3** 6.9 ... ... ... ... ...
*Not included as a separate question in 1990 survey. Ellipses indicate data not applicable.
†The 1997 question asked about severe depression, which is not directly comparable with the 1990 question that asked about depression.
‡The 1997 question asked about anxiety attacks, which is not directly comparable with the 1990 question that asked about anxiety.
§The weighted averages are calculated based on all 37 conditions studied in 1997 and all 24 conditions studied in 1990, ie, condition is unit of analysis.
\This row shows percentage of respondents who reported 1 or more principal medical conditions, along with the percentage of these respondents who reported use of therapy
or practitioners for at least 1 of these conditions, ie, person is the unit of analysis.
¶
P
#.05; #
P
#.01; **
P
,.001.
JAMA, November 11, 1998—Vol 280, No. 18 Trends in Alternative Medicine Use in the United States—Eisenberg et al 1573
©1998 American Medical Association. All rights reserved.
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reports concerning recollections of num-
ber of visits and amounts spent on books,
classes, relevant equipment, herbs, or
supplements. To the extent possible, we
adjusted by weighting data on sociode-
mographic variables associated with al-
ternative therapy use (eg, income, edu-
cation, age, region). It is conceivable that
the estimated prevalence and costs of al-
ternative therapy use would have been
lower if it were possible to correct for
those limitations.
Within the context of these limitations,
theresults of these2 surveys suggestthat
the prevalence and expenditures associ-
ated with alternative medical therapies
in the United States have increased sub-
stantiallyfrom 1990 to 1997. Thisincrease
appears to be primarily due to increases
in the prevalence of use and in the fre-
quency with which users of alternative
therapy sought professional services. In
1997,an estimated 4 in 10Americans used
at least 1 alternative therapy as com-
pared with 3 in 10 in 1990. For adults aged
35 to 49 years in 1997, it is estimated that
1 of every 2 persons used at least 1 alter-
native therapy. Overall prevalence of use
increased by 25%, total visits by an esti-
mated 47%, and expenditures on services
provided by practitioners of alternative
therapies by an estimated 45% exclusive
of inflation. Moreover, the use of alterna-
tivetherapies is distributed widelyacross
all sociodemographic groups.
It is possible to arrange the 16 princi-
pal therapies common to the 1990 and
1997 surveys along a spectrum that var-
ies from “more alternative” to “less alter-
native” in relationship to existing medi-
cal school curricula, clinical training, and
practice. Arguably, therapies such as bio-
feedback, hypnosis, guided imagery, re-
laxation techniques that involve elicita-
tion of the relaxation response (,1% of
the sample), lifestyle diet, and (possibly)
vitamintherapy can be considered asrep-
resentative of the more conventional (ie,
less alternative) side of the spectrum.
Visits associated with these 6 categories
accounted for less than 10% of total visits
to alternative medicine practitioners; the
remainderwere associated with the more
alternative therapies.
In light of the observed 380% increase
in the use of herbal remedies and the
130% increase in high-dose vitamin use,
it is not surprising to find that nearly 1 in
5 individuals taking prescription medi-
cations also was taking herbs, high-dose
vitamin supplements, or both. Extrapo-
lations to the total US population sug-
gest that an estimated 15 million adults
are at risk for potential adverse interac-
Table 4.—Insurance Coverage of Alternative Medicine Services in the United States, 1997 vs 1990*
Type of Therapy
Percentage of Users of Services
Coverage, 1997 Coverage, 1990
Complete Partial None Complete Partial None
Relaxation techniques 28.8 6.6 64.7 5.3 25.9 68.7
Herbal medicine 8.6 11.2 80.2 30.7 15.5 53.8
Massage 11.8 16.7 71.5 19.1 18.3 62.6
Chiropractic 17.6 38.1 44.3 11.5 32.8 55.9
Spiritual healing by others† . . . . . . . . . 0.0 0.0 100.0
Megavitamins 2.7 53.3 44.0 0.0 100.0 0.0
Self-help group 11.7 36.9 51.5 2.8 17.4 79.8
Imagery 51.5 3.5 45.0 16.1 0.0 83.9
Commercial diet 5.0 40.1 54.9 0.0 5.1 94.9
Folk remedies 0.0 0.0 100.0 . . . . . . . . .
Lifestyle diet 0.0 44.9 55.1 62.3 0.0 37.7
Energy healing 30.8 8.2 61.1 0.0 19.1 80.9
Homeopathy 0.0 0.0 100.0 0.0 24.7 75.3
Hypnosis 5.1 0.0 94.9 7.0 0.0 93.0
Biofeedback 30.5 43.7 26.0 14.1 19.9 66.0
Acupuncture 0.0 40.7 59.3 21.6 23.0 55.4
Weighted average across all therapies 15.3 26.4 58.3 12.3 23.7 64.0
*Data are percentageof usersof alternative therapiesprovided bypractitioners. Ellipses indicatedata notapplicable.
†Reimbursement patterns not explored in 1997.
Table5.—National Projections of ExpendituresforAlternativeTherapies intheUnited States, 1997 vs1990*
Category of Expenditure
1997
(Billions of Dollars)
1990
(Billions of Dollars)
Change (%),
1997 vs 1990
(Billions of Dollars)
Conservative
(SE)
RBRVS
(SE)
Conservative
(SE)
RBRVS
(SE) Conservative RBRVS
Total expenditures on
professional services for 15
alternative therapies†
21.2 (2.4) 32.7 (3.8) 14.6 (4.0) 22.6 (6.1) 6.6 (45.2) 10.1 (44.7)
Out-of-pocket expenditures
Professional services, 15
therapies†‡
12.2 (1.7) 19.6 (3.3) 7.2 (1.3) 11.0 (2.1) 5.0 (69.4)§ 8.6 (78.2)§
Megavitamins 3.3 (0.4) 0.9 (0.3) 2.4 (266.7)\
Commercial diet products 1.7 (0.3) 1.3 (0.3) 0.4 (30.8)
Subtotal of out-of-pocket
expenditures assessed in
1997 and 1990†
17.2 24.6 9.4 13.2 7.8 (83.0) 11.4 (86.4)
Out-of-pocket expenditures
assessed only in 1997
Herbal medicine 5.1 (0.5) . . . . . .
Therapy-specific books,
classes, and equipment
4.7 (0.8) . . . . . .
Total out-of-pocket
expenditures for alternative
therapies in 1997†
27.0 34.4 . . . . . . . . . . . .
*The 1990 and 1997 cost measures are based on 1990 and 1997 population estimates, respectively (180 million vs
198 million). Both used 1997 per-visit price estimates as follows (conservative price estimate is followed by Resource-
BasedRelativeValueScale[RBRVS]estimateforeachtherapy):relaxationtechniques($20,$50),herbalmedicine($40,
$60), massage therapy ($40, $60), chiropractic care ($40, $65), megavitamins ($40, $50), self-help groups ($20, $20),
imagery techniques ($45, $50), commercial diet ($20, $20), folk remedies ($20, $50), lifestyle diet ($20, $60), energy
healing ($40, $50), homeopathy ($45, $60), hypnosis ($60, $80), biofeedback ($60, $80), and acupuncture ($40, $60).
(Price estimates for spiritual healing by others were not included because respondents reporting use were not asked
for details of professional visits). Ellipses indicate data not applicable.
†These figures reflect the range in out-of-pocket expenditures for conservative vs RBRVS-derived visit prices.
‡Assumes a 20% copayment for users with partial insurance coverage.
§
P
#.05.; \
P
#.001.
40
5
10
0
15
20
25
30
35
Annual Out-of-Pocket Expenditures, $ in Billions
Upper
Bound
(RBRVS
Prices)
$34.4
5.1
3.3
4.7
1.7
$19.6
Lower
Bound
(Conservative
Prices)
$27.0
5.1
3.3
4.7
1.7
$12.2
Out-of-Pocket
All US
Physician
Services
21
$29.3
Out-of-Pocket
All US
Hospital-
izations
21
$9.1
Herbal Products
High-Dose Vitamins
Diet Products
Professional Services
Therapy-Specific Books, Classes, Etc
Figure 2.—Estimated annual out-of-pocket expen-
ditures for alternative therapies vs conventional
medical services, United States, 1997. Data are
from the Health Care Financing Administration,
UnitedStates.
21
RBRVSindicates Resource-Based
Relative Value Scale.
1574 JAMA, November 11, 1998—Vol 280, No. 18 Trends in Alternative Medicine Use in the United States—Eisenberg et al
©1998 American Medical Association. All rights reserved.
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tions involving prescription medications
and herbs or high-dose vitamin supple-
ments. This figure includes nearly 3
million adults aged 65 years or older. Ad-
verse interactions of this nature, includ-
ing alterations of drug bioavailability
or efficacy, are known to occur
23-27
and
are more likely among individuals with
chronic medical illness, especially those
with liver or kidney abnormalities. No
adequate mechanism currently is in
place to collect relevant surveillance
data to document the extent to which the
potential for drug-herb and drug-vita-
min interaction is real or imaginary.
The magnitude of the demand for al-
ternative therapy is noteworthy, in light
of the relatively low rates of insurance
coverage for these services. Unlike hos-
pitalizations and physician services, al-
ternative therapies are only infrequently
included in insurance benefits. Even
when alternative therapies are covered,
they tend to have high deductibles and
co-payments and tend to be subject to
stringent limits on the number of visits or
total dollar coverage. Because the de-
mand for health care (and presumably al-
ternative therapies) is sensitive to how
much patients must pay out-of-pocket,
28
current use is likely to underrepresent
utilization patterns if insurance coverage
for alternative therapies increases in the
future.
In 1990, a full third of respondents who
used alternative therapy did not use it
for any principal medical condition.
1
From these data, we inferred that a sub-
stantial amount of alternative therapy
was used for health promotion or disease
prevention. In 1997, 42% of all alterna-
tive therapies used were exclusively at-
tributed to treatment of existing illness,
whereas 58% were used, at least in part,
to “prevent future illness from occur-
ring or to maintain health and vitality.”
Despite the dramatic increases in use
and expenditures associated with alter-
native medical care, the extent to which
patients disclose their use of alternative
therapiesto their physiciansremains low.
Less than 40% of the alternative thera-
pies used were disclosed to a physician in
both 1990 and 1997. It would be overly
simplistic to blame either the patient or
their physician for this inadequacy in pa-
tient-physician communication. The cur-
rent status quo, which can be described
as “don’t ask and don’t tell,” needs to be
abandoned.
29
Professional strategies for
responsible dialogue in this area need to
be further developed and refined.
Data from this survey, reflective of
the US population, are representative of
a predominantly white population. Even
if we were to combine data sets from the
1990 and 1997 surveys, we would not
have a sufficiently large database to pro-
vide precise estimates of the patterns of
alternative therapy use among African
Americans, Hispanic Americans, Asian
Americans, or other minority groups.
Parallel surveys, modified to include
therapiesunique to minority populations
andtranslated when appropriate, should
be conducted using necessary sampling
strategies. Only then can we compare
patterns across ethnic groups and pri-
oritize research agendas for individual
populations. As alternative medicine is
introduced by third-party payers as an
attractive insurance product, it would be
unfair for individuals without health in-
surance and those with less expendable
income to be excluded from useful alter-
native medical services or consultation
(eg, professional advice on use or avoid-
ance of alternative therapies).
In conclusion, our survey confirms
that alternative medicine use and expen-
ditures have increased dramatically
from 1990 to 1997. In light of these ob-
servations, we suggest that federal
agencies, private corporations, founda-
tions, and academic institutions adopt a
more proactive posture concerning the
implementation of clinical and basic sci-
ence research, the development of rel-
evant educational curricula, credential-
ing and referral guidelines, improved
quality control of dietary supplements,
and the establishment of postmarket
surveillance of drug-herb (and drug-
supplement) interactions.
This study was supported in part by National In-
stitutes of Health grant U24 AR43441, Bethesda,
Md, the John E. Fetzer Institute, Kalamazoo, Mich,
The American Society of Actuaries, Schaumburg,
Ill, the Friends of Beth Israel Deaconess Medical
Center, and the Kenneth J. Germeshausen Foun-
dation, Boston, Mass, and the J. E. and Z. B. Butler
Foundation, New York, NY.
The authors thank the staff of DataStat, Inc, Ann
Arbor, Mich, for their assistance with telephone
data collection, Linda Bedell-Logan for assistance
with RBRVS data analyses, Dan Cherkin, PhD,
Murray Mittleman, MD, Ted Kaptchuk, OMD, and
Thomas Delbanco, MD, for their review of the
manuscript, and Debora Lane, Marcia Rich, and
Robb Scholten for their technical assistance.
References
1. Eisenberg DM, Kessler RC, Foster C, et al. Un-
conventional medicine in the United States. N Engl
J Med. 1993;328:246-252.
2. Paramore LC. Use of alternative therapies.
J Pain Symptom Manage. 1997;13:83-89.
3. Landmark Healthcare.The Landmark Reporton
Public Perceptions of Alternative Care. Sacra-
mento, Calif: Landmark Healthcare; 1998.
4. Pelletier KR, Marie A, Krasner M, et al. Current
trends in the integration and reimbursement of
complementary and alternative medicine by man-
aged care, insurance carriers, and hospital provid-
ers. Am J Health Promot. 1997;12:112-122.
5. Wetzel MS, Eisenberg DM, Kaptchuk TJ.
Courses involving complementary and alternative
medicine at US medical schools. JAMA. 1998;280:
784-787.
6. Goldbeck-Wood S, Dorozynski A, Lie LG, et al.
Complementary medicine is booming worldwide.
BMJ. 1996;313:131-133.
7. Rasmussen NK, Morgall JM. The use of alterna-
tive treatments in the Danish adult population.
Complementary Med Res. 1990;4:16-22.
8. Vaskilampi T, Merila¨inen P, Sinkkonen S, et al.
The use of alternative treatments in the Finnish
adult population. In: Lewith GT, Aldridge D, eds.
Clinical Research Methodology for Complemen-
tary Therapies. London, England: Hodder &
Stoughton; 1993:204-229.
9. MacLennan AH, Wilson DH, Taylor AW. Preva-
lence and cost of alternative medicine in Australia.
Lancet. 1996;347:569-573.
10. Fisher P, Ward A. Complementary medicine in
Europe. BMJ. 1994;309:107-111.
11. Sermeus G. Alternative health care in Belgium.
Complementary Med Res. 1990;4:9-13.
12. Bouchayer F. Alternative medicines. Comple-
mentary Med Res. 1990;4:4-8.
13. Piel E. Erfahrungen mit Naturheilmitteln-Um-
frageergebnisse aus West-und Ostdeutschland.
Therapeutikon. 1991;5:549-551.
14. Millar WJ. Use of alternative health care prac-
titioners by Canadians. Can J Public Health. 1997;
88:154-158.
15. US Bureau of the Census. United States popu-
lation estimates, by age, sex, race, and Hispanic ori-
gin, 1990 to 1997. Available at: http://www.census
.gov/population/estimates/nation/intfile2-1.txt.
16. Resource-Based Relative Value Scale Con-
verter. Customized Report for Medical Billing and
Collection of All CPT Codes. Salt Lake City, Utah:
Medicode Inc; 1996.
17. US Bureau of Labor Statistics Data. Consumer
Price Index—All Urban Consumers. US Bureau of
Labor Statistics Web site. Available at: http://
146.142.4.24/cgi-bin/surveymost?cu. 1998. Series
ID: CUUR0000SAM.
18. SUDAAN: Professional Software for Survey
Data Analysis [computer program]. Version 7.5.
Research Triangle Park, NC: Research Triangle In-
stitute; 1997.
19. Schappert SM. National Ambulatory Medical
Care Survey: 1990 Summary. Hyattsville, Md: Na-
tional Center for Health Statistics, 1992. Advance
Data FromVital and Health Statistics, No. 213:1-11.
20. Woodwell DA. National Ambulatory Medical
Care Survey: 1996 Summary. Hyattsville, Md:
National Center for Health Statistics; 1997. Ad-
vance Data From Vital and Health Statistics, No.
295:1-25.
21. Health Care Financing Administration, Office
of the Actuary, National Health Statistics Group.
National healthcare expenditure projectionstables.
Available at: http://www.hcfa.gov/stats/NHE-Proj
/tables/.
22. Groves RM, Couper MP. Societal environmen-
tal influences on survey participation. In: Nonre-
sponse in Household InterviewSurveys. New York,
NY: John Wiley & Sons Inc; 1998:159.
23. Ernst E. Harmless herbs? Am J Med. 1998;104:
170-178.
24. D’Arcy PF. Adverse reactions and interactions
with herbal medicines, part 1: adverse reactions.
Adverse Drug React Toxicol Rev. 1991;10:189-208.
25. D’Arcy PF. Adverse reactions and interactions
with herbal medicines, part 2: drug interactions.
Adverse Drug React Toxicol Rev. 1993;12:147-162.
26. De Smet PAGM, D’Arcy PF. Drug interactions
with herbal and other non-orthodox remedies. In:
D’Arcy PF, McElnay JC, Welling PG, eds. Mecha-
nisms of Drug Interactions. New York, NY:
Springer Publishing Co Inc; 1996:327-352.
27. De Smet PA. Health risks of herbal remedies.
Drug Saf. 1995;13:81-93.
28. Shekelle PG, Rogers WH, Newhouse JP. The
effect of cost sharing on the use of chiropractic ser-
vices. Med Care. 1996;34:863-872.
29. Eisenberg DM. Advising patients who seek al-
ternative medical therapies. Ann Intern Med. 1997;
127:61-69.
JAMA, November 11, 1998—Vol 280, No. 18 Trends in Alternative Medicine Use in the United States—Eisenberg et al 1575
©1998 American Medical Association. All rights reserved.
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