 |
|
Insurance Coverage, Medical Conditions, and Visits to Alternative Medicine Providers
Results of a National Survey
Peter M. Wolsko, MD;
David M. Eisenberg, MD;
Roger B. Davis, ScD;
Susan L. Ettner, PhD;
Russell S. Phillips, MD
Arch Intern Med. 2002;162:281-287.
ABSTRACT
| |
Background In 1997, patients made an estimated 629 million visits to complementary
and alternative medicine (CAM) providers; however, little is known about factors
associated with visits to CAM providers.
Objective To examine the effect of insurance coverage on frequency of use of CAM
providers.
Methods We conducted a nationally representative, random household telephone
survey of 2055 adults.
Main Outcome Measure The number of visits made to CAM providers.
Results An estimated 44% of the US population used at least 1 CAM therapy in
1997. Of those using CAM, 52% had seen at least 1 CAM provider in the last
year. Among those who used a CAM therapy, factors independently associated
with seeing a provider were having been in the upper quartile of visits to
conventional providers in the last year (adjusted odds ratio [AOR], 2.00;
95% confidence interval [CI], 1.33-3.01), female sex (AOR, 1.67; 95% CI, 1.17-2.38),
and having used the therapy to treat diabetes (AOR, 5.20; 95% CI, 1.40-19.40),
cancer (AOR, 2.99; 95% CI, 1.04-8.62), or back or neck problems (AOR, 1.51;
95% CI, 1.02-2.23). Factors independently associated with frequent use ( 8
visits per year) of a CAM provider were full insurance coverage of the CAM
provider (AOR, 5.06; 95% CI, 2.45-10.47), partial insurance coverage (AOR,
3.26; 95% CI, 1.72-6.19), having used the therapy for wellness (AOR, 2.85;
95% CI, 1.63-4.98), and having seen the provider for back or neck problems
(AOR, 2.26; 95% CI, 1.29-3.94). Conservative extrapolation to national estimates
suggests that 8.9% of the population (17.5 million adults) accounted for more
than 75% of the 629 million visits made to CAM providers in 1997.
Conclusions A small minority of persons accounted for more than 75% of visits to
CAM providers. Extent of insurance coverage for CAM providers and use for
wellness are strong correlates of frequent use of CAM providers.
INTRODUCTION
NATIONAL SURVEYS demonstrate a substantial and growing number of visits
to complementary and alternative medicine (CAM) providers.1-2
In 1990, there were 1.1 times more visits to CAM providers than to primary
care physicians; in 1997, this ratio increased to 1.6 and amounted to 629
million CAM provider visits. Despite the medical and health policy importance
of this large and increasing number of visits to CAM providers, few data are
available examining factors associated with use or frequent use of these providers.
Extensive conventional health services research has noted many factors
to be correlated with increased frequency of ambulatory service utilization,
including female sex,3 older age,4
worse health status,5-6 presence
of health insurance,7-8 health
maintenance organization enrollment,9 and presence
of a psychiatric disorder.5, 10-11
For chiropractic care, extent of insurance coverage and provision of health
promotion and disease prevention are correlates of more frequent visits.12-14 In one study of the
effect of insurance coverage on visit frequency, Shekelle and colleagues15 reported that those with full coverage made twice
as many visits to chiropractors compared with those with no coverage or those
participating in a 25% cost-sharing plan. Correlates of use of chiropractors
have not been examined in a national sample. The effect of CAM provider insurance
coverage or other factors on frequency of CAM provider use for providers other
than chiropractors has not been examined previously. Therefore, our objective
was to investigate patterns and correlates of use and frequent use of CAM
providers, using data available from a national survey.
METHODS
SURVEY DESIGN AND RESPONSE RATE
We conducted a nationally representative telephone survey between November
1, 1997, and February 28, 1998. We used random-digit dialing with random selection
of 1 English-speaking household resident 18 years or older. We weighted the
data to adjust for geographic variation in response rates and for variation
in household size and the probability of selection. We used sociodemographic
variables to adjust for aggregate discrepancies between the sample distributions
and population distributions provided by the US Census Bureau.
We presented the interview as a survey conducted about the health care
of Americans with no mention of alternative or complementary therapies. Questions
began with assessment of current health status, interactions with physicians,
and personal experience during the last 12 months with common medical conditions.
We then asked about the use of CAM therapies. The CAM therapies consisted
of a core list of 15 modalities outlined in previous work2
(relaxation techniques, herbal medicine, massage, chiropractic, megavitamins,
self-help group, imagery, commercial diet, folk remedies, lifestyle diet,
energy healing, homeopathy, hypnosis, biofeedback, and acupuncture) as well
as additional CAM therapies that are less easily defined and were used less
frequently than those in the core list. Therapies specifically not included
in the definition of CAM for our analyses were spiritual healing by others,
self-prayer, and exercise. For a random sample of up to 3 CAM therapies used
by the respondent, we asked in-depth questions about the use of this modality.
We have published previously additional details of the sampling methods and
interview.2 The study methods were approved
by the institutional review board at Beth Israel Deaconess Medical Center.
We obtained a 60% weighted overall response rate among eligible respondents.
The characteristics of the subjects interviewed were similar to the population
distributions published by the US Census Bureau. Specific respondent characteristics,
additional details of the weighting procedures, and general survey results
have been published previously.2
ANALYSIS
We determined the total number of visits made to CAM providers by each
respondent by an exact count for those reporting use of 3 or fewer different
CAM therapies. For the 21% of CAM users who reported use of 4 or more different
CAM therapies, exact counts were available only for the 3 randomly selected
therapies. To use these respondents in the descriptive analysis, we estimated
the total number of CAM providers seen and the number of visits made for each
additional CAM therapy.
The likely number of visits made for each additional CAM therapy in
question was estimated by multiplying the probability that a person using
the CAM modality in question would have seen a provider by the mean number
of visits made to that type of provider. For these probabilities, we examined
respondents who gave detailed information on the use of the CAM modality in
question and determined the average probability of seeing a CAM provider and
the average number of visits made among those reporting use of a provider.
To estimate the number of different types of CAM providers seen by respondents
who used more than 3 CAM modalities, we added the number of the modalities
for which they actually reported seeing a provider (eg, 0, 1, 2, or 3) to
the probabilities that they saw a provider for the additional CAM modalities
in question. These probabilities were determined as described herein. The
mean number of different types of CAM providers seen was then rounded up or
down as appropriate (for example, if a respondent was estimated to have seen
1.3 different CAM providers, he or she was classified as having seen 1 CAM
provider).
Regression analyses used data on therapies for which exact counts were
available and did not use any estimated data.
The following example illustrates the estimation techniques used. A
respondent used 4 CAM modalities (herbal therapies, chiropractic, acupuncture,
and massage) and was randomly asked specific details about all therapies except
massage. The respondent reported no provider use for herbal therapies but
saw an acupuncturist 3 times and a chiropractor 9 times. Information given
by other respondents who gave detailed information regarding their use of
massage demonstrated that 60% reported use of a massage provider and those
using providers made an average of 8.0 visits for massage. For this respondent,
the estimated total number of visits made to CAM providers was 3 + 9 + [0.6
x 8] = 16.8, whereas the estimated number of CAM providers seen was
3 (rounded up from 2.6).
We performed 2 primary multivariable logistic regression analyses. In
the first analysis, we determined factors associated with visiting a provider
for a given CAM therapy among respondents who had reported use of at least
1 CAM therapy in the last year. We excluded patients seen for chiropractic
and acupuncture treatment since nearly all patients who reported use of these
modalities saw providers. This analysis distinguished use of CAM as self-care
(eg, getting a massage from a friend) from use of a CAM professional (eg,
seeing a massage therapist). The percentage of respondents seeing a professional
ranged from 6% for folk remedies to 63% for hypnosis. In the second analysis,
we determined factors associated with high-frequency use of a given type of
CAM provider among respondents who reported making at least 1 visit to at
least 1 type of CAM provider in the last year (including chiropractic and
acupuncture). We defined a high-frequency user of a CAM provider as a respondent
who made 8 or more visits to a given type of CAM provider in the last year,
which corresponded to the upper tertile of visits made to any 1 type of CAM
provider. Because we collected data on up to 3 different CAM therapies, a
respondent could be classified as a high-frequency user of up to 3 different
therapies. For example, a respondent who visited a chiropractor 9 times and
a massage therapist 5 times in the last year was classified as a high-frequency
user of chiropractic but not of massage therapy.
For our analyses, we assessed the strength of bivariable associations
between the independent variable and other factors, including patient characteristics.
Factors evaluated for significance in both models were sociodemographic variables,
measures of current health status, prior use of conventional medical care,
and reasons for seeing the CAM provider. For the model investigating factors
associated with frequent CAM provider use, we also evaluated the associations
with extent of insurance coverage provided for the specific type of CAM practitioner
seen.
Sociodemographic variables included sex, quintile of age, race (white
vs other), educational level (college graduate or higher vs others), household
income, household size, type of conventional health insurance (health maintenance
organization, private, Medicare or Medicaid, other, or none), national region
of residence (East, West, Northeast, Southeast), and town size (as quartiles).
Measures of current health status included very good or excellent self-rated
health and having 3 or more self-reported medical problems. Presence of a
psychiatric disorder was assessed via self-report of difficulties with anxiety
attacks or severe depression during the last 12 months or having seen a mental
health professional during the last 12 months for 1 of their 3 most concerning
medical problems. We classified a respondent as a high user of conventional
medical care if his or her report of the number of visits made to physicians
or assistants for a health problem or a checkup in the last year was in the
upper quartile of responses. Reasons for seeing the CAM provider included
the common medical problems for which the respondent had seen the CAM provider
(back or neck problems, allergies, headaches or other chronic pain, lung problems,
arthritis, cancer, diabetes, heart problems, gastrointestinal complaints,
and fatigue) and whether the respondent had used the therapy for wellness.
Extent of insurance coverage was classified as none, partial, or full. We
were unable to investigate the association between insurance coverage and
any use of a CAM provider because we did not have CAM insurance information
for respondents who did not report visits to providers.
We used a backward elimination procedure to create the final models.
Analyses were restricted to variables significant at P .20
in our bivariable analyses. We performed secondary analyses to examine high-frequency
CAM provider use of "manipulative" providers only (chiropractic and massage)
and "nonmanipulative" providers only (all CAM providers except chiropractic
and massage). Because of more limited sample sizes, these analyses were restricted
to variables significant in the primary analysis. In our analysis of frequent
CAM provider use, 24% of respondents contributed information on visits to
more than one type of provider. In our analysis of any CAM provider use, 54%
of respondents contributed information on use of more than 1 CAM therapy.
To control for type of modality used to the greatest extent possible, all
models were adjusted for therapies used by more than 3% of respondents. We
used modeling by linear regression with generalized estimating equations,
accounting for patient-level clustering where the unit of observation was
person therapy.16 All analyses were performed
using SUDAAN statistical software (Research Triangle Institute, Research Triangle
Park, NC) with appropriate weighting and nesting variables.
RESULTS
Overall, 2055 respondents completed the survey, of whom 914 (44% weighted)
reported using at least 1 CAM therapy in the last year. Of those using CAM
in the last year, the number of different modalities used by each respondent
was as follows (Figure 1A): 1 therapy,
46.0%; 2 therapies, 20.0%; 3 therapies, 12.9%; 4 therapies, 7.4%; 5 therapies,
5.3%; 6 therapies, 2.8%; and 7 or more therapies, 5.5%. Of respondents using
CAM in the last year, an estimated 48.2% used only self-care–centered
CAM, whereas 51.8% had seen a CAM provider: 32.7% saw 1 type of CAM provider,
10.8% saw 2 different types of CAM providers, and 8.2% saw 3 or more different
types of CAM providers (Figure 1B).
|
|
|
|
Figure 1. A, Number (percentage) of different
complementary and alternative medicine (CAM) modalities used in the last year
among CAM users. B, Number (percentage) of different CAM provider types seen
in the last year among CAM users.
|
|
|
FACTORS ASSOCIATED WITH ANY USE OF A CAM PROVIDER
Factors independently associated with use of a CAM provider among patients
who used a given CAM therapy are presented in Table 1. These factors were having been in the upper quartile of
visits to conventional providers in the last year; female sex; and using the
therapy to treat diabetes, cancer, and back or neck problems. Of note, users
of CAM providers were not significantly different from those reporting self-care
CAM use in terms of age, race, region of residence, education, income, and
presence of a psychiatric disorder.
|
|
|
|
Table 1. Factors Independently Associated With Use of Complementary
and Alternative Medicine (CAM) Professionals Among Respondents Using CAM Therapies
in the Last Year*
|
|
|
PATTERNS OF CAM PROVIDER USE
Overall, 19% of respondents gave detailed information on visits to CAM
practitioners seen in the last year. The mean and median numbers of visits
to any 1 type of CAM provider were 10.3 and 4.0, respectively. The mean and
median numbers of visits to all types of CAM providers combined were 14.6
and 7.4, respectively. The distributions of total number of visits made to
all types of CAM providers combined and to conventional physicians in the
last 12 months are shown in Figure 2.
Approximately 26% of respondents made at least 1 visit to a CAM provider.
Although the distribution of visits to CAM providers varied based on type
of modality used, the percentage of users who made 8 or more visits was generally
comparable across the more frequently used modalities. There was no statistical
difference in the percentage of patients who made 8 or more visits to CAM
providers for providers seen by more than 5% of respondents (chiropractic,
massage, relaxation techniques, diet programs) compared with those who saw
other types of providers (P = .28). Those respondents
whose estimated total number of visits to all CAM providers combined was in
the upper tertile accounted for 77.7% of all visits to CAM providers. Conservative
extrapolation to national estimates suggests that 8.9% of the population,
or 20.5% of CAM users (17.5 million adults), accounted for more than 75% of
the 629 million visits estimated to have been made to CAM providers in 1997.
|
|
|
|
Figure 2. Distribution of visits made in
the last year to complementary and alternative medicine (CAM) and conventional
providers.
|
|
|
FACTORS ASSOCIATED WITH FREQUENT USE OF CAM PROVIDERS
The 397 respondents (19% weighted) who gave detailed information on
visits to CAM providers provided data on 576 respondent–CAM provider
relationships because some respondents saw more then 1 type of CAM provider.
The adjusted odds ratios for the factors associated with frequent use of a
given type of CAM provider are presented in Table 2. The factors independently associated with being a high-frequency
user of a specific type of CAM therapy were full or partial insurance coverage
of the CAM provider (compared with no coverage of CAM provider), having used
the therapy for wellness, and having seen the provider for back or neck problems.
Other factors, including age, sex, socioeconomic status, health status measures,
presence of a psychiatric disorder, and region of residence, were not significantly
associated with high-frequency CAM provider use. Being in the upper quartile
of visits to conventional providers was not associated with high-frequency
CAM provider use in bivariable (P = .10) or multivariable
(P = .30) analyses.
|
|
|
|
Table 2. Factors Independently Associated With High-Frequency Use of
a Complementary and Alternative Medicine (CAM) Provider
|
|
|
Results of secondary analyses specifically focused on manipulative (chiropractic
or massage) or nonmanipulative providers are also given in Table 2. For manipulative providers, full insurance coverage, partial
insurance coverage, and using the therapy for wellness were associated with
high-frequency provider use. Full and partial insurance coverage emerged as
particularly strong correlates of frequent CAM provider use for manipulative
providers. Among respondents visiting these providers, 63% of those reporting
full insurance coverage of these providers made 8 or more visits in the last
year, whereas only 17% of those reporting no insurance coverage of these providers
made 8 or more visits. For nonmanipulative providers, the only factor from
the primary model significantly associated with high-frequency provider use
was having used the therapy for wellness.
We examined whether the effect of full insurance was significantly different
than partial coverage by creating a model using partial coverage as the reference
group. The effect of full insurance coverage was not significantly different
than partial coverage for either the primary model or the manipulative therapy
provider model (P = .22 and P
= .24, respectively).
COMMENT
A small minority of people who used CAM providers accounted for most
of the overall visits made to those providers, in a pattern similar to that
demonstrated for use of conventional medical care.17-18
Although CAM was used by approximately 44% of the population, our study suggests
that only 8.9% of the population accounted for more than 75% of the 629 million
visits estimated to have been made to CAM providers in 1997. Insurance coverage
of CAM providers and having used the CAM therapy for wellness were the strongest
correlates of high-frequency CAM provider use.
Extent of insurance coverage emerged as a strong correlate of high-frequency
use of CAM providers, particularly in the case of manipulative therapies.
We are uncertain whether this represents selection bias (eg, people chose
plans that covered CAM providers because they planned to use CAM therapies)
or moral hazard (eg, people used more because they were given coverage). A
report of a 70% increase in chiropractic use after addition of mandatory coverage
and other randomized controlled studies of chiropractic insurance coverage
suggests moral hazard may play an important role.15, 19
Our results suggest that insurance coverage may play an important role in
determining the number of visits that will be made to CAM providers in the
future. However, since the relationship between high-frequency CAM provider
use and insurance coverage seems to have been strongly driven by the subset
of manipulative therapies, effects may be most dramatic for visits to chiropractic
and massage provider. With current trends of providing increased insurance
coverage for CAM modalities,20 CAM provider
visits may continue to increase dramatically.
Using a CAM therapy for wellness is associated with frequent CAM provider
use. The desire for wellness and preventive care has been suggested elsewhere
as a primary motivation for the use of CAM.21-22
Previous research suggests that obtaining this care from conventional and
unconventional sources is important to CAM users. For example, Druss and Rosenheck23 found that persons making visits to CAM providers
and conventional providers were more likely than persons visiting only conventional
providers to report having obtained commonly used preventive services, including
blood pressure and cholesterol levels and prostate and breast cancer screening.
Astin et al24 recently surveyed enrollees in
a Medicare supplement plan offering selected CAM benefits and found that the
most frequently cited reason for using CAM therapies was "general health improvement"
(42%), whereas "chronic medical problems" was cited by only 18% of respondents
as the reason for CAM use. Whether use of CAM providers for wellness and preventive
care is because of patient frustration with deficiencies of the conventional
system is unclear.25-26 In the
case of chiropractic therapy, maintenance care has been correlated with more
frequent visits. Maintenance care is a term used
by chiropractors to describe regular visits made for such purposes as optimizing
health and minimizing recurrences or exacerbations of conditions. It may consist
of manipulative procedures and counseling regarding exercise, stretching,
and diet.27 As many as 80% of chiropractic
patients will have maintenance care recommended to them, accounting for up
to 23% of chiropractors' practice income.28
High-frequency use of conventional providers was associated with use
of a CAM provider among those using a CAM therapy. Similarly, a recent study
by Druss and Rosenheck23 found that those in
the highest quartile of physician visits were more than twice as likely to
have visited a CAM provider in the last year. However, these investigators
did not present data on frequency of visits to CAM providers. We did not find
the presence of a psychiatric disorder to be associated with use or frequent
use of CAM providers. This stands in contrast to studies of conventional medicine,
which show a strong correlation between psychiatric diagnoses and more frequent
medical care use.5, 10-11
Although our results may have been due to self-reporting bias or inadequate
statistical power, our results do not support the notion that presence of
a psychiatric disorder is an important correlate of CAM provider use.
Our analysis has several limitations. First, our visit data were based
on self-report, and our results are subject to recall bias. However, recall
tends to underestimate the actual number of visits made as the number of visits
increases.29 Therefore, this bias may lead
to an underestimation of the contribution to visits made by high-frequency
users of CAM services. Second, sample size restrictions required us to combine
CAM modalities when determining factors correlated with use of CAM providers
and frequent CAM provider use. Our grouping was supported by our observation
that the most frequently used CAM modalities had similar percentages of high-frequency
users and by our adjustment for type of therapy for commonly used modalities.
However, for the less frequently used modalities, different patterns of use
might have been due to small sample subsets or true differences in visit frequency
to different types of providers. Third, because our sample size was limited
for some analyses, we may not have had sufficient power to detect small-to-moderate
differences among various groups. For example, our lack of finding a significant
relationship between full or partial insurance coverage and frequent use of
nonmanipulative CAM providers (Table 2)
may have been due to inadequate power. Finally, estimation procedures used
to calculate the number of different providers seen and the total number of
visits made to CAM providers resulted in slight discrepancies in our calculations
and may have introduced some bias into our results. However, because estimation
was required for only 21% of CAM users, any discrepancies or bias introduced
was small and do not affect our conclusions. Our analyses suggest that if
the estimation procedures biased results, it was in the direction of underestimation
of the total number of visits made to CAM providers and underestimation of
the proportion of visits made by respondents using 4 or more CAM modalities.
Examples describing how calculation discrepancy and bias may have been introduced
are described in the box on this page.
In summary, we found that 8.9% of the overall population accounted for
more than 75% of the 629 million visits estimated to have been made to CAM
providers in 1997. Factors associated with high-frequency use of CAM providers
were full and partial insurance coverage of the CAM provider and using the
CAM therapy for wellness or for back or neck problems, whereas the presence
of chronic medical conditions was associated with any use of CAM providers.
Needs for wellness and preventive care are emerging as factors of prime importance
to CAM users. Research is needed to determine whether patient perceptions
of appropriate wellness and preventive care are based on unrealistic expectations
of health care in general or CAM therapies specifically or if they reflect
worthy and realistic goals. Our finding that full or partial insurance coverage
is strongly associated with high-frequency use of CAM providers has implications
for use of CAM providers in the future, given current trends of increasing
insurance coverage of CAM providers. Future research must focus on clinical
outcomes and cost-effectiveness of preventive and interventional treatments
provided by CAM providers. Until better data are available, insurers should
proceed cautiously when considering extending CAM benefits.
AUTHOR INFORMATION
Accepted for publication May 8, 2001.
This study was supported by National Institutes of Health (Bethesda,
Md) grant U24 AR43441; The John E. Fetzer Institute, Kalamazoo, Mich; The
American Society of Actuaries, Schaumburg, Ill; The Friends of Beth Israel
Deaconess Medical Center; The Kenneth J. Germeshausen Foundation, Boston,
Mass; the J. E. and Z. B. Butler Foundation, New York, NY; and an Institutional
National Research Service Award for Training in Alternative Medicine Research
(T32 AT00051) (Dr Wolsko), National Institutes of Health.
| Calculation Discrepancy and Bias
For example, a respondent who was estimated to have seen 0.35 providers
would have been described as having seen 0 CAM providers, but would have been
counted as contributing 0.35 x N visits to CAM providers, where N is
the mean number of visits to the type of provider the respondent might have
seen. Bias may have been introduced as indicated by the following factors:
respondents visiting chiropractors who used 4 or more CAM modalities made
an average of 12.2 visits to chiropractors, whereas those visiting chiropractors
who used 2 or fewer CAM modalities made an average of 7.7 visits to chiropractors
(data not shown).
|
|
Corresponding author and reprints: Peter M. Wolsko, MD, Beth Israel
Deaconess Medical Center, Libby 330, 330 Brookline Ave, Boston, MA 02215 (e-mail: pwolsko{at}caregroup.harvard.edu).
From the Center for Alternative Medicine Research and Education, Division
of General Medicine and Primary Care, Beth Israel Deaconess Medical Center,
and Department of Medicine, Harvard Medical School, Boston, Mass (Drs Wolsko,
Eisenberg, Davis, and Phillips); and the Department of Medicine, University
of California–Los Angeles (Dr Ettner).
REFERENCES
| |
1. Eisenberg DM, Kessler RC, Foster C, et al. Unconventional medicine in the United States: prevalence, costs, and
patterns of use. N Engl J Med. 1993;328:246-252.
FREE FULL TEXT
2. Eisenberg DM, Davis RB, Ettner SL, et al. Trends in alternative medicine use in the United States, 1990-1997:
results of a follow-up national survey. JAMA. 1998;280:1569-1575.
FREE FULL TEXT
3. Green CA, Pope CR. Gender, psychosocial factors and the use of medical services: a longitudinal
analysis. Soc Sci Med. 1999;48:1363-1372.
4. Kleinman JC, Gold M, Makuc D. Use of ambulatory medical care by the poor: another look at equity. Med Care. 1981;19:1011-1029.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
5. Pearson SD, Katzelnick DJ, Simon GE, Manning WG, Helstad CP, Henk HJ. Depression among high utilizers of medical care. J Gen Intern Med. 1999;14:461-468.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
6. Bohlan J. Neighborhood variations in the use of hospital emergency rooms for
primary care. Soc Sci Med. 1984;19:1217-1226.
7. Broyles RW, McAuley WJ, Baird-Holmes D. The medically vulnerable: their health risks, health status, and use
of physician care. J Health Care Poor Underserved. 1999;10:186-200.
WEB OF SCIENCE
| PUBMED
8. Weissman JS, Epstein AM. The insurance gap: does it make a difference? Annu Rev Public Health. 1993;14:243-270.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
9. Tu HT, Kemper P, Wong HJ. Do HMOs make a difference? use of health services. Inquiry. 1999-00;36:400-410.
10. Katon W. Panic disorder: relationship to high medical utilization, unexplained
physical symptoms, and medical costs. J Clin Psychiatry. 1996;57 Suppl 10:11-18.
11. Unutzer J, Patrick DL, Simon G, et al. Depressive symptoms and the cost of health services in HMO patients
aged 65 and older: a 4-year prospective study. JAMA. 1997;277:1618-1623.
FREE FULL TEXT
12. Leboeuf C, Morrow JD, Payne RL. A preliminary investigation of the relationship between certain practice
characteristics and practice location: chiropractor-population ratio. J Manipulative Physiol Ther. 1989;12:253-258.
PUBMED
13. Stano M. A comparison of health care costs for chiropractic and medical patients. J Manipulative Physiol Ther. 1993;16:291-294.
PUBMED
14. Stano M. A comparison of healthcare costs for chiropractic and medical patients. Paper presented at: Low-back Problems Clinical Guideline Open Forum;
1992.
15. Shekelle PG, Rogers WH, Newhouse JP. The effect of cost sharing on the use of chiropractic services. Med Care. 1996;34:863-872.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
16. Zeger SL, Liang KY. Longitudinal data analysis for discrete and continuous outcomes. Biometrics. 1986;42:121-130.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
17. Von Korff M, Ormel J, Katon W, Lin EH. Disability and depression among high utilizers of health care: a longitudinal
analysis. Arch Gen Psychiatry. 1992;49:91-100.
FREE FULL TEXT
18. Taube CA, Goldman HH, Burns BJ, Kessler LG. High users of outpatient mental health services, I: definition and
characteristics. Am J Psychiatry. 1988;145:19-24.
FREE FULL TEXT
19. Blue Cross/Blue Shield. The Financial Impact of Chiropractic Benefits on
Health Care in Arizona, 1983-1986. Phoenix, Ariz: Blue Cross/Blue Shield; 1987.
20. Pelletier KR, Marie A, Krasner M, Haskell WL. Current trends in the integration and reimbursement of complementary
and alternative medicine by managed care, insurance carriers, and hospital providers. Am J Heath Promot. 1997;12:112-122.
21. Oubre A. Social context of complementary medicine in western society: part I. J Altern Complement Med. 1995;1:41-56.
PUBMED
22. Astin JA. Why patients use alternative medicine: results of a national survey. JAMA. 1998;279:1548-1553.
FREE FULL TEXT
23. Druss BG, Rosenheck RA. Association between use of unconventional therapies and conventional
medical services. JAMA. 1999;282:651-656.
FREE FULL TEXT
24. Astin JA, Pelletier KR, Marie A, Haskell WL. Complementary and alternative medicine use among elderly persons: one-year
analysis of a Blue Shield Medicare supplement. J Gerontol A Biol Sci Med Sci. 2000;55:M4-M9.
25. Brull R, Ghali WA, Quan H. Missed opportunities for prevention in general internal medicine. CMAJ. 1999;160:1137-1140.
ABSTRACT
26. Elrick H. A new definition of health. J Natl Med Assoc. 1980;72:695-699.
PUBMED
27. Rupert RL. A survey of practice patterns and the health promotion and prevention
attitudes of US chiropractors: maintenance care: part I. J Manipulative Physiol Ther. 2000;23:1-9.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
28. Rupert RL, Manello D, Sandefur R. Maintenance care: health promotion services administered to US chiropractic
patients aged 65 and older: part III. J Manipulative Physiol Ther. 2000;23:10-19.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
29. Roberts RO, Bergstralh EJ, Schmidt L, Jacobsen SJ. Comparison of self-reported and medical record health care utilization
measures. J Clin Epidemiol. 1996;49:989-995.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati  Twitter
What's this?
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
|
Who Uses CAM? A Narrative Review of Demographic Characteristics and Health Factors Associated with CAM Use
Bishop and Lewith
Evid Based Complement Alternat Med 2010;7:11-28.
ABSTRACT
| FULL TEXT
Use of Complementary and Alternative Medicine in Patients Suffering from Primary Headache Disorders
Gaul et al.
Cephalalgia 2009;29:1069-1078.
ABSTRACT
| FULL TEXT
Prescriptions of Chinese Herbal Medicines for Insomnia in Taiwan during 2002
Chen et al.
Evid Based Complement Alternat Med 2009;0:nep018v1-nep018.
ABSTRACT
| FULL TEXT
A longitudinal analysis of older Australian women's consultations with complementary and alternative medicine (CAM) practitioners, 1996-2005
Adams et al.
Age Ageing 2009;38:93-99.
ABSTRACT
| FULL TEXT
Public Status and Prevalence of Acupuncture in Japan
Ishizaki et al.
Evid Based Complement Alternat Med 2008;0:nen037v2-nen037.
ABSTRACT
| FULL TEXT
The Use of Complementary/Alternative Therapies Among Children Attending an Urban Pediatric Emergency Department
Sawni et al.
CLIN PEDIATR 2007;46:36-41.
ABSTRACT
"Have You Seen Your Aura Lately?" Examining Boundary-Work in Holistic Health Pamphlets
Ho
Qual Health Res 2007;17:26-37.
ABSTRACT
Acute Toxicity Pilot Evaluation of Proliferol in Rats and Swine
Dagenais et al.
International Journal of Toxicology 2006;25:171-181.
ABSTRACT
| FULL TEXT
Use of Complementary and Alternative Medicine by Older Adults: An Exploratory Study
Montalto et al.
Complementary Health Practice Review 2006;11:27-46.
ABSTRACT
Use of Complementary Medicine in Older Americans: Results From the Health and Retirement Study
Ness et al.
The Gerontologist 2005;45:516-524.
ABSTRACT
| FULL TEXT
Prevalence, Pattern and Predictors of use of Complementary and Alternative Medicine (CAM) in Migraine Patients Attending a Headache Clinic in Italy
Rossi et al.
Cephalalgia 2005;25:493-506.
ABSTRACT
| FULL TEXT
Mainstreaming Complementary Therapies: New Directions In Health Care
Ruggie
Health Aff (Millwood) 2005;24:980-990.
ABSTRACT
| FULL TEXT
Cracking the Problem of Back Pain: Is Chiropractic the Answer?
Ness and Nisly
Arch Intern Med 2004;164:1953-1954.
FULL TEXT
Cancer and Complementary and Alternative Medicine in Italy: Personal Observations and Historical Considerations
Moss
Integr Cancer Ther 2004;3:173-188.
ABSTRACT
Decreasing, Null and Increasing Effects of Eight Popular Types of Ginseng on Acute Postprandial Glycemic Indices in Healthy Humans: The Role of Ginsenosides
Sievenpiper et al.
J. Am. Coll. Nutr. 2004;23:248-258.
ABSTRACT
| FULL TEXT
Use of Complementary and Alternative Medicines by Ambulatory Patients
Rhee et al.
Arch Intern Med 2004;164:1004-1009.
ABSTRACT
| FULL TEXT
Null and Opposing Effects of Asian Ginseng (Panax ginseng C.A. Meyer) on Acute Glycemia: Results of Two Acute Dose Escalation Studies
Sievenpiper et al.
J. Am. Coll. Nutr. 2003;22:524-532.
ABSTRACT
| FULL TEXT
Predictors of alternative medicine use by multiple sclerosis patients
Marrie et al.
Mult Scler 2003;9:461-466.
ABSTRACT
On Equivalence Trials and Alternative Medicine
Yueh and Piccirillo
Arch Otolaryngol Head Neck Surg 2003;129:403-404.
FULL TEXT
|
