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To quantify how visits and expenditures differ between insured patients with fibromyalgia syndrome (FMS) who visit complementary and alternative medicine (CAM) providers compared with patients with FMS who do not. Patients with FMS were also compared with an age- and sex-matched comparison group without FMS.
Calendar year 2002 claims data from 2 large insurers in Washington state were analyzed for provider type (CAM versus conventional), patient comorbid medical conditions, number of visits, and expenditures.
Use of CAM by patients with FMS was 2.5 times higher than in the comparison group without FMS (56% versus 21%). Patients with FMS who used CAM had more health care visits than patients with FMS not using CAM (34 versus 23; P < 0.001); however, CAM users had similar expenditures to nonusers among patients with FMS ($4,638 versus $4,728; not significant), because expenditure per CAM visit is lower than expenditure per conventional visit. Patients with FMS who used CAM also had heavier overall disease burdens than those not using CAM.
With insurance coverage, a majority of patients with FMS will visit CAM providers. The sickest patients use more CAM, leading to an increased number of health care visits. However, CAM use is not associated with higher overall expenditures. Until a cure for FMS is found, CAM providers may offer an economic alternative for patients with FMS seeking symptomatic relief.
Fibromyalgia syndrome (FMS) is a chronic, painful condition of unknown cause that has no definitive cure (1, 2). Patients with FMS have high rates of medical care use with associated high expenditures (3–9), likely due to a continuing search for relief from chronic soft tissue pain, fatigue, and sleep disturbance (10–12). Surveys have documented that complementary and alternative medicine (CAM) therapies are used by most patients with FMS in their search for relief; several reports have estimated that >90% of patients with FMS use CAM (1, 13, 14), many seeing CAM providers such as massage therapists (range of use 44–53% of patients with FMS), chiropractors (37–47%), acupuncturists (11–22%), and naturopathic physicians (37%) (13–15).
Some CAM use may be attributable to the effectiveness of the treatment. Pain relief in patients with FMS has been demonstrated in controlled trials of acupuncture (16–19), although a recent trial found no beneficial effect (20). There are also suggestions that chiropractic care (2) and connective tissue massage (21) may provide short-term symptom relief. However, the effectiveness of most CAM therapies remains unproven. The appeal of CAM providers may arise primarily from the hope that CAM providers offer (9), the time and attention they give to patients (22), and their empathy and listening skills (23).
Given the high annual medical expenditures for conventional care among patients with FMS, third-party payers have been concerned about the consequences of adding coverage for CAM provider care. Insurance leads to increased use of certain types of health services (24, 25), but adding CAM coverage may not necessarily increase expenditures if it replaces more expensive conventional services. Since 1996 in Washington state, private commercial insurance companies are required by law to have a CAM provider benefit, which allowed us to use insurance claims to investigate 3 issues. First, how does CAM use by insured patients with FMS compare with CAM use in other insured patients? Second, among patients with FMS who use CAM providers, how is their health care utilization apportioned between CAM and conventional care? Finally, how do health care expenditures differ between patients with FMS who use CAM and those who do not?
PATIENTS AND METHODS
We created a cross-sectional cohort of adults with FMS using claims data from 2 large insurers in Washington state. The analysis was limited to enrollees in health insurance plans directly regulated by the law requiring CAM coverage in the year 2002. This excluded Medicare, Medicaid, state-supplemental programs, and self-insured plans that are exempt from state regulation. The analyses presented here were limited to adults ages 18–64 years who had both continuous enrollment in a single plan and complete claims information for the year 2002. The claims came from a variety of plans with differing benefit structures, deductibles, and copayments. However, in general the access to CAM providers under each plan was similar to access to conventional providers. Self-referral to chiropractic providers was allowed under all plans. There were generally visit limits for CAM providers, which affected the amount paid to CAM providers by the insurance company but not the prevalence of CAM use.
Expenditures were measured using the amount allowed by the insurance company for each visit. Visits that were disallowed by the insurance company were excluded from the analysis (4.6% of all claims among patients with FMS). Total expenditures included all claims paid by the insurance company, and as such included inpatient, outpatient, skilled nursing facility, home health care, and other claims paid by the insurance company except payments for pharmaceutical claims, which were considered separately.
A visit was defined as a claim from a unique provider with a unique date. That is, a person could not have more than 1 visit to a given provider on one day. Visits do not always correspond one-to-one with submitted claims. Also, although we generally refer to these unique encounters as visits, they also include claims that did not correspond to an actual office visit, such as hospital claims, laboratory claims, and others.
The study population for this analysis consisted of adults with a diagnosis of fibromyalgia (International Classification of Disease, Ninth Revision [ICD-9] code 729.1) at ≥1 allowed provider visits. We also repeated the analyses requiring 2 separate claims with an FMS diagnosis to define FMS, in order to look at possible effects of false positives due to rule out codings or miscoding of diagnoses on insurance claims (26–28). Also, requiring 2 FMS diagnoses singled out the heaviest health care users and thus represented a worst case scenario in terms of adding to health care expenditures. To compare CAM use by patients with FMS and patients without FMS, we randomly selected an age- and sex-matched set of insured adults who had at least 1 outpatient visit during the year but had no visits for fibromyalgia.
Providers were divided into 3 groups. CAM providers were defined as chiropractors, licensed massage therapists, acupuncturists, and naturopathic physicians. Conventional providers were defined as physicians (including all specialists), physical therapists, occupational therapists, mental health providers (e.g., psychologists, counselors, social workers), podiatrists, advanced registered nurse practitioners, and physician assistants. All providers who did not fit into either of these categories were put into a third category called “other.” Chiropractic care has been covered by insurance for many years, whereas coverage for the other CAM provider types is much more recent. Therefore, for some analyses the nonchiropractic provider types were grouped as Naturopathic physicians, Acupuncturists, and Massage therapists (NAM providers).
CAM users were defined as patients with ≥1 visits to a CAM provider. It is important to note that this was a self-selected group of patients who chose to use CAM providers for some or all of their care. Although this self-selection implies that there is almost certainly selection bias present in the group that chose to use CAM, our analyses may indicate how CAM coverage might be expected to be used in other real life settings in which patients choose whether or not to use a covered CAM benefit.
Other medical conditions.
Using the Johns Hopkins Adjusted Clinical Group software, version 6 (29), we constructed 2 measures of the types of diseases or disorders present and the expected resource utilization for each patient. The first measure was the Expanded Diagnosis Clusters (EDCs), which categorized ICD-9 codes into 26 major disease categories and then created 26 indicator variables for the presence or absence of each category for each individual. The second measure was an index of overall disease burden, which we referred to as morbidity group and was based on the Adjusted Clinical Group (ACG) index. The ACG index is an overall measure of disease burden and expected resource use and has 82 categories (30). The morbidity groups created from this index collapsed the 82 categories into 5 groups based on similarity of expected resource use. The cut points for the 5 groups were calculated at Johns Hopkins using a national sample. Lower morbidity groups included individuals with less expected resource use and higher morbidity groups included those with greater expected resource use.
Predictors of CAM use were modeled using logistic regression. Independent variables were age group (18–25 years and then 5-year age groups from 26–30 years to 61–64 years), sex, county population indicators, insurance product line (preferred provider organization, point of service, and traditional fee-for-service compared with health maintenance organization), indicators for EDC categories, and indicators for the level of expected resource use (measured by morbidity categories).
Expenditures were modeled using linear regression. Although expenditure data were skewed, our data set was large enough that ordinary least squares regression provided accurate estimates of coefficients and standard errors (31). Independent variables were use of CAM, age group, sex, county size, type of insurance product, indicators for EDC categories, indicators for morbidity category, and interactions between the morbidity category indicators and use of CAM. Morbidity categories were included to compare expenditures between CAM users and nonusers after adjusting for differences in the expected resource use in these 2 groups. Stata statistical software, version 8.0 was used for all analyses (32).
The study population for this analysis is described in Table 1. The data file included 497,648 adults with allowed claims, of whom 13,792 (2.8%) had FMS (based on 1 or more claims related to FMS). The median age of patients with FMS with allowed claims was 47 years, and 74% were women. The comparison group included 41,427 individuals without FMS who were age- and sex-matched to the patients with FMS. Distributions of all individuals with allowed claims, patients with FMS, and the comparison group were similar for insurance product line and for county population (except that CAM users in the comparison group were less likely to live in the largest counties). Patients with FMS differed from the other groups in their distribution between insurance companies and distribution of morbidity categories. Only 2% of patients with FMS were in the lowest morbidity category compared with 28% of the comparison group.
Table 1. Characteristics of the study population and comparison group: adults (ages 18–64 years) with private commercial insurance coverage in Washington state*
Values are the percentage unless otherwise indicated. CAM = complementary and alternative medicine; NAM = naturopathic physician, acupuncturist, or massage therapist; FMS = fibromyalgia syndrome; HMO = health maintenance organization; PPO = preferred provider organization; POS = point of service.
Patients with FMS, defined as 1 or more claims containing International Classification of Diseases, Ninth Revision (ICD-9) code 729.1.
Randomly selected patients who did not have any visits with ICD-9 codes for FMS, age- and sex-matched to patients with FMS.
Low = morbidity category 1 or 2; middle = morbidity category 3; high = morbidity category 4 or 5.
The rates of CAM provider use by patients with FMS and the comparison group are described in Table 2. Among the patients with FMS, 7,221 (56%) had at least 1 visit to a CAM provider, and 4,554 of these (33% of all patients with FMS with allowed claims) had at least 1 visit to a NAM provider. This represented much higher CAM utilization than was seen in the random comparison group, of whom 21% had 1 or more visits to a CAM provider, and 7% had 1 or more visits to a NAM provider. The difference in CAM use was most striking for acupuncture and massage, where the rate among patients with FMS was >5 times the rate in the comparison group.
Table 2. Provider types used among patients with FMS and comparison group*
Random comparison group
Values are the number (percentage). See Table 1 for definitions.
Visits and expenditures.
Overall, patients with FMS had an average of 29 outpatient visits per year. Patients with FMS who used any CAM had significantly more annual visits (mean ± SD 34 ± 25) than those who did not use CAM (mean ± SD 23 ± 21; P < 0.001) (Figure 1). In both CAM users and nonusers, most conventional visits were made either to physicians (76–79%) or physical therapists (10–12%); 4–5% of visits were made to mental health professionals.
Expenditures demonstrated a different pattern. Mean ± SD annual expenditures (including both inpatient and outpatient charges) were similar between patients with FMS who used CAM and those who did not use CAM ($4,638 ± $9,660 and $4,728 ± $10,564, respectively) (data not shown). Outpatient expenditures were also similar between CAM users and nonusers (mean ± SD $3,473 ± $4,926 and $3,269 ± $6,489, respectively) (Figure 2). The mean ± SD allowed amount for a CAM visit was much lower than that of a conventional visit ($56 ± $31 and $130 ± $277, respectively) (data not shown). CAM users had slightly higher total average annual expenditures than CAM nonusers in the lower half of the expenditure distribution, ranging from $40 higher at the 1st percentile to $500 higher at the 50th percentile. However, this difference was offset in the upper end of the distribution, where CAM users had substantially lower average annual expenditures than nonusers (for example, $2,600 lower at the 95th percentile and $14,000 lower at the 99th percentile) (data not shown).
Furthermore, although CAM visits accounted for 25% of all claims among all patients with FMS in 2002 (98,780 of 399,709 claims), CAM expenditures accounted for only 8% of the total expenditures by patients with FMS ($5.5 million of $65.2 million). CAM claims among patients who used CAM accounted for an average of 42% of their annual outpatient claims, but the average CAM expenditure of $718 was only 21% of the average annual outpatient expenditures of $3,473 in this group (Figures 1 and 2). For comparison, conventional claims comprised 53% of all outpatient claims and 45% of expenditures.
Different patterns of visits and expenditures were seen in the random comparison group. In this group, CAM users had twice as many visits as nonusers (Figure 1), and CAM users also had higher expenditures than nonusers (Figure 2).
Among patients with FMS, the relationship between average expenditures in CAM users and nonusers was complicated by an interaction between CAM use and morbidity category. In the regression models adjusted for sex, age, insurance product and company, county population size, indicators for EDC categories, indicators for morbidity category, and the interaction between morbidity category and use of CAM, we found that CAM users had higher expenditures than nonusers in the low morbidity categories but lower expenditures in the highest morbidity category (Table 3).
Table 3. Average expenditures by complementary and alternative medicine (CAM) use and morbidity category, from linear regression analysis*
Independent variables were CAM use indicator, morbidity category indicators, interactions between CAM use and morbidity category indicators, age, sex, county population, insurance product indicators, insurance company, and Expanded Diagnosis Clusters category indicators.
Beta coefficients show the amount that average annual expenditures differed from CAM nonusers in the lowest morbidity category. For CAM users, beta coefficients were obtained by summing the coefficients for CAM use, morbidity category, and the interaction of CAM use and morbidity category. Positive values indicate higher expenditures than the reference category, and negative values indicate lower expenditures than the reference category.
Pharmaceutical claims were considered separately. CAM users had both fewer pharmacy claims during the year (20.4 versus 26.6; P < 0.001) and lower pharmacy expenditures ($1,914 versus $2,346; P = 0.002).
Predictors of CAM use.
In the logistic regression analysis of patients with FMS, by far the strongest predictor of CAM use was being in morbidity category 3, 4, or 5 (odds ratio [OR] 5.4–10.0). Female sex was also associated with slightly greater odds of CAM use (OR 1.3). Compared with patients ages 18–25 years, the odds of CAM use were higher in patients ages 26–40 years and lower in those ages 56–64 years (Table 4).
Table 4. Predictors of CAM use among patients with FMS, from logistic regression model*
OR (95% CI)
Also adjusted for insurance company, product type, and Expanded Diagnosis Clusters indicators. OR = odds ratio; 95% CI = 95% confidence interval; see Table 1 for additional definitions.
Analysis using 2 visits to define FMS.
We repeated these analyses restricting the FMS group to those with at least 2 claims for ICD-9–identified FMS during the year. There were 7,626 patients with FMS according to this definition, 68% of whom had at least 1 CAM visit. The observed patterns were similar to those reported here, with CAM claims among CAM users accounting for 44% of these patients' claims but only 18% of their expenditures. Using this definition, CAM users had significantly lower annual expenditures than nonusers ($4,390 versus $5,535; P < 0.001).
We studied the extent to which patients with FMS would visit CAM providers when this method of care was covered by insurance. Our results demonstrated that more than half of patients with FMS visited a CAM provider during a 1-year period, compared with 21% of the comparison group. The purpose of the comparison group was to give us an idea of how a cross-section of patients chose to use CAM providers when they were covered by insurance. In this insured group, patients with FMS visited CAM providers at a much higher rate than other patients, which was similar to previous reports that did not consider insurance coverage.
Use of chiropractic care in our sample of patients with FMS was similar to previous studies of patients with FMS (41% compared with 37–47%) (14, 15), but use of NAM providers was lower than in previous FMS studies (13, 15). This finding may merely reflect differences between survey data and claims data or the small sample size in the previous reports, or it may reflect the fact that chiropractic care has a long history of inclusion in insurance coverage, whereas coverage of NAM providers is newer. Use of NAM by patients with FMS may increase as patients become more aware of its availability under insurance coverage.
Although patients with FMS who used CAM had more visits during the year than those not using CAM, they had similar overall insurance expenditures for provider care, both outpatient and total. The average annual expenditure to CAM providers of $718 was offset by slightly lower expenditures for outpatient conventional care and inpatient care. This implies that covering CAM care is not resulting in additional cost to the insurance company. However, had CAM providers not been included under insurance coverage, we cannot say the extent to which CAM care would have been replaced by additional conventional care, paid for out of pocket, or foregone altogether. We cannot determine whether our results are due to self-selection by patients who used CAM or whether some effect of CAM care actually reduced other expenditures. Therefore we cannot determine conclusively the effect of CAM coverage on insurance expenditures for patients with FMS. Most of the insurance plans included in these claims had visit limits on the use of CAM providers. If patients with FMS had used additional conventional care once the CAM limits were reached, we would have expected to see higher expenditures in this group rather than lower. We do not know if these patients continued to see CAM providers and paid out of pocket, or if the amount of CAM care received provided enough relief to obviate the need for additional conventional care. In either case, our conclusion that patients with FMS who used CAM providers had similar overall insurance expenditures is unchanged. Additionally, our results do provide information on how patients may use a CAM benefit in the real world, in which they will self-select whether or not to use covered CAM benefits.
The above discussion includes only provider-based claims and not pharmacy claims, where expenditures for CAM users were an average of $432 lower than average pharmacy expenditures for those not using CAM. This saving offsets more than half of the average annual expenditure to CAM providers.
This analysis has several limitations. First, not all patients with FMS seek medical care for FMS in a 1-year period (3). We do not know how our results would have differed if we had looked at a longer period and thus included patients with less frequent utilization. Second, these data contain limited information on personal characteristics of the patients, limiting our ability to adjust for potentially confounding demographic factors such as income, education, and race. Third, because patients were not randomized to CAM use, self-selection bias is likely present in these data. Using risk adjustment indices such as the ACG-based morbidity groups mitigates this bias but does not remove it entirely, and we do not know the effect of any residual bias. Finally, we did not include any noninsured CAM use such as the use of herbal remedies or nutritional supplements. Our intent was to show the impact of insurance coverage on insurance expenditures. Our results do not generalize to patients without insurance coverage for CAM providers, but seem to suggest that coverage of CAM by public programs such as Medicare and Medicaid would not increase expenditures, and in fact might even lead to lower expenditures among the heaviest health care users (e.g., those with 2 or more FMS-related visits per year).
Until a cure for FMS is found, CAM providers may offer an economic alternative for symptomatic relief. Pain is a subjective outcome, so patient perception of the effectiveness of care may have higher relative importance in this setting than for other disorders with more objective biologic outcomes. Therefore further research will be important to assess patient perceptions of the effectiveness of CAM care compared with conventional care, and to ascertain whether in the long run CAM care may truly be cost effective.
Dr. Lind had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study design. Drs. Lind, Lafferty, Diehr, and Grembowski.
Acquisition of data. Drs. Lafferty and Tyree.
Analysis and interpretation of data. Drs. Lind and Tyree.
Manuscript preparation. Drs. Lind, Lafferty, Tyree, Diehr, and Grembowski.