Search tips
Search criteria 


Logo of nihpaAbout Author manuscriptsSubmit a manuscriptHHS Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
Am J Manag Care. Author manuscript; available in PMC 2008 November 25.
Published in final edited form as:
PMCID: PMC2587209

CAM Provider Use and Expenditures by Cancer Treatment Phase



To assess cancer patients’ utilization of complementary and alternative medical providers and the associated expenditures by specific treatment phases.

Study Design

Cross-sectional analysis of medical services utilization and expenditures during three therapeutic intervals: an initial treatment phase, continuing care, and end-of-life.


Analysis of an insurance claims database that had been matched to the Washington State SEER cancer registry.


Of 2,900 registry-matched cancer patients 63.2% were female, the median age was 54 years, and 92.7% were white. Breast cancer was the most frequent diagnosis (52.7%), followed by prostate cancer (24.7%), lung cancer (10.1%), colon cancer (7.0%), and hematologic malignancies (5.6%). CAM provider using patients were 26.5% of the overall cohort (18.5% used chiropractors, 7.7% naturopathic physicians, 5.3% massage therapists, and 4.2% saw acupuncturists). The proportion of CAM using patients was similar during each treatment phase. All patients used some conventional care. Female gender, a breast cancer diagnosis, age, and white race were significant predictors of CAM use. Diagnosis of a musculoskeletal problem occurred at sometime during the study for 72.1% of cancer patients. CAM provider visits were 7.2% of total outpatient medical visits and 85.1% of CAM visits resulted in a musculoskeletal diagnosis. Expenditures for CAM providers were 0.3%, 1.0%, and 0.1% of all expenditures during the initial, continuing, and end-of-life phases respectively.


For cancer patients, musculoskeletal issues were the most commonly listed diagnosis made by a CAM provider. Although expenditures associated with CAM are a small proportion of the total, additional studies are necessary to determine the importance patients place on access to these services.

Keywords: Alternative Medicine, Oncology, Healthcare Expenditures, Treatment Phase

Cancer is the second leading cause of death in the U.S.1 The American Cancer Society estimates that in 2007 over 1.4 million new cancer cases will be diagnosed and over 500,000 people will die of this disease.2 Cancer treatment costs are substantial due to the direct cost of new, increasingly expensive treatment3 and the enormous indirect cost associated with time spent during treatment for the patients and their family members.4 Patient surveys have shown that some of these expenditures are for complementary and alternative medical providers because over 70% of cancer patients will use some form CAM after the diagnosis of cancer and that at least 16% of cancer patients visit a CAM provider.5 Reasons for CAM use by cancer patients include the treatment of specific symptoms,611 female gender, a diagnosis of breast cancer, and white race.12

Previous health services research studies have grouped conventional provider utilization and expenditures for cancer care based on time intervals post diagnosis. To accomplish this, Medicare datasets have been matched to cancer registry data.13, 14 This adds diagnostic detail and mortality endpoints that are present in registry data to claim-based administrative data. These registry matched cancer studies have been able to describe health care utilization by treatment phase (in the initial 12 months following diagnosis, utilization in the last year of life, and the continuing period between these two phases.)4 Utilization analysis during each phase captures a different picture of cancer care than does a single cross-sectional evaluation. This type of evaluation has not been done to assess the use of complementary and alternative medical providers for cancer treatment.

Historically, third party payment records have been a poor choice for studying CAM provider services because CAM care has traditionally been paid for out-of-pocket15 and large public payers, such as Medicare, do not cover most CAM provider services. Some states have taken legislative steps to change this and integrate CAM providers into mainstream health care finance.16, 17 In 1996, Washington State passed legislation requiring every category of licensed health care provider to be covered by private insurance. This mandated the inclusion of acupuncturists, naturopathic physicians, and massage therapists into commercial insurance products; legislative mandates in 1983 had already covered chiropractors.18 Thus, Washington State’s mandate for CAM coverage created a large bank of insurance claims data where CAM providers have been consistently covered since 2000. Matching enrollment and claims data from a subset of individuals who were privately insured from 2000–2004 to the Fred Hutchinson Cancer Research Center’s (FHCRC) Western Washington Surveillance, Epidemiology, and End Results (SEER) cancer registry identified a cohort of patients with insurance claims and registry information. These data were used to assess the factors that predict CAM use by distinct therapeutic phases, the medical reasons for CAM use during these phases, and the proportion of expenditures resulting from CAM provider care.



This study was approved by the institutional review boards of the University of Washington and the FHCRC. Eligible participants consisted of registry-matched cancer patients 18 to 64 who were diagnosed with breast, colorectal, hematologic, lung, or prostate cancer From January 2000 through December 2003 and had no prior cancer diagnosis. In addition, eligibility criteria included insurance coverage at time of diagnosis, and maintaining coverage at least 12 months after diagnosis or in the situation of survival less than one year, contiguous coverage from diagnosis to death. A large, private provider of multiple insurance product types supplied the insurance data.


The researchers received separate insurance files with enrollment and medical claims (utilization and expenditures) data for 2000 through 2004. The techniques used to process these data and define study variables have been previously described.19 CAM providers included chiropractors, naturopathic physicians, massage therapists, and acupuncturists. CAM and conventional provider visits were defined as outpatient if they were occurred at a hospital based outpatient clinic or a provider’s office.20 The participants’ zip codes of residence were classified as urban versus non-urban using the Rural Urban Commuting Area (RUCA) method.21 International Classification of Disease (ICD9) codes were categorized into major diagnosis categories using the Johns Hopkins Adjusted Clinical Groups software.22 All expenditures were adjusted 2004 dollars based on the consumer price index for medical care.23 Chemotherapy, radiation therapy, and surgery were defined by Current Procedural Terminology24 codes.(Appendix 1)

Participants were identified through a confidential link of the insurance data and the SEER cancer registry. At the time of the link, SEER maintained diagnosis and death information from 1974 though 2006 and covered 13 Western Washington State counties. The features of this registry have been previously described.25 Cancer site and stage at diagnosis, as well as the diagnosis and death dates were taken from the SEER record. Cancer stage was grouped to local (in situ and localized) and all other.

Participants’ health care utilization data were categorized into three clinically relevant treatment phases: initial, continuing, and end-of-life. The treatment phase definitions were based on the published paper by Yabroff et al;4 exceptions to their model are described below. The initial phase represented the first 12 months after diagnosis; the end-of-life phase represented the 12 months preceding death; and the continuing phase represented the time between initial and end-of-life. For patients surviving less than 24 months, the last 12 months were assigned to end-of-life and the remaining months were assigned to the initial phase; the continuing phase was not represented in this scenario. Unlike Yabroff, the end-of-life phase was defined as diagnosis through death when survival was less than 12 months. When participants survived greater than 12 months after the available insurance data, the end point for the continuing phase was December 2004; else, the end point was 12 months prior to the date of death. The number of continuing months ranged from 1 to 48 (median 16, mean 19.0). To approximate the length of the initial and end-of-life phases for analysis of expenditures, the data in the continuing phase were adjusted to an annual figure by taking each individual’s monthly mean in that phase and multiplying by 12. Data were not adjusted in the initial or end-of-life phases. Unlike Yabroff, no modifications were made to the length of initial stage based on cancer diagnosis.

Statistical Analysis

Logistic regression assessed the potential predictors of CAM use during each study phase. Separate regressions were done for each predictor of interest, as no adjustments were made for other covariates. Odds ratios were considered statistically significant at the 0.05 level, corresponding to a 95% confidence interval (CI) not containing 1.0. No adjustments were made for multiple comparisons. All analyzes were conducted using STATA version 9.2.26


Population and Sample

Of 900,000 people with private insurance coverage from 2000–2004, 2,900 were registry-matched cancer patients that met study criteria. The study population (2,900) is described in Table 1. In the study population, 93.0%, 84.8%, and 10.7% of the patient participants had data for the initial, continuing, and end-of-life phases respectively. A majority of patient participants were urban, white, and female. Breast cancer accounted over 52.7% of all cancer diagnoses followed by prostate, lung, colorectal, and hematologic malignancies. Patients with lung cancer accounted for 58.7% of patients in the end of life treatment phase. The median age of all cases at diagnosis was 54 years, and almost 2/3 of participants were diagnosed with localized cancer. Point-of-service (POS) and preferred provider organization (PPO) insurance products, and group policies were the predominant forms of coverage. Patients with at least one claim from a CAM provider accounted for 26.5% of the cumulative cancer patient cohort. The use of different CAM provider types was not mutually exclusive. Chiropractors were the most commonly used CAM provider. The prevalence of CAM claims was higher, though not statistically so, in the continuing phase (21.8%), and the initial phase (19.5%), as compared to the end-of-life (17.7%). All patients used some form of conventional care.

Table 1
Population and Sample

Predictors and Reasons for CAM Use

Table 2 describes potential predictors of CAM use during each of the three treatment phases. The estimated odds of CAM use for those diagnosed with breast cancer were significantly higher than those diagnosed with colorectal cancer during both the initial phase (OR: 1.85 95% CI: 1.19 –2.87) and the continuing phase (OR: 2.04 95% CI: 1.29 – 3.22). The estimated odds of CAM use were not significantly different for patients with hematologic malignancies, prostate, and lung cancer compared to colorectal cancer. No significant differences were found between the estimated odds of CAM use for those presenting with local cancer compared to those presenting with non-local cancer during the initial phase (OR:1.17 95% CI: 0.96 – 1.43). For patients differing in one year of age, the estimated odds for CAM utilization were marginally lower for older patients during both the initial and continuing phase. Individuals with group policies were associated with higher odds of CAM use compared to individual polices during the continuing phase only (OR 1.58 95% CI 1.14–2.18). Individuals with an insurance product other than PPO and POS had slightly higher CAM use in the continuing phase and for the aggregated phases than individuals with a POS. CAM use did not vary significantly between individuals residing in an urban and non-urban setting. .

Table 2
Predictors of Complementary and Alternative Medicine Provider Use*

Female gender was positively associated with CAM use during all three treatment phases. The odds of CAM use among women for the aggregated phases were estimated to be 1.79 times the odds of CAM use among males (95% CI: 1.49 to 2.14). Adjusting for a musculoskeletal diagnosis, the estimated odds ratio of CAM use between men and women remains statistically significant (OR: 1.54 95% CI: 1.27 –1.86). Stratifying on cancers common among men and women – colorectal, hematologic, and lung – the odds of CAM use for women was estimated to be 80% higher than the odds for men (OR: 1.82 95% CI: 1.24 – 2.66).

Visits to CAM providers accounted for 13,858 (7.2%) outpatient medical care visits during the study interval: chiropractic (4.7%), massage therapy (1.1%), naturopathic physician (0.8%), and acupuncture (0.6%) (data not shown), For patients who used CAM, the median number of CAM visits was 6 during the initial phase, 6 during the continuing phase, and 2 visits at the end-of-life phase. Due to the high acuity of conventional care during the initial and end-of-life treatment phases, CAM provider visits were a very small proportion of all outpatient provider visits (4.9% and 2.1% respectively). Conversely, CAM provider visits were 11.9% of all total visits during the continuing phase.

Table 3 shows the diagnoses associated with CAM and conventional medical care visits during all phases of the study. The diagnostic information present at each visit indicated that over the course of the study 2,092 (72.1%) cancer patients saw an outpatient provider for a musculoskeletal complaint, accounting for 23,038 (12.0%) visits. Musculoskeletal diagnoses were noted at 11,800 (85.1%) CAM visits and accounted for almost all visits to chiropractors, massage therapists, and acupuncturists. Similar to conventional providers, naturopathic physicians assigned a broader array of diagnoses and specifically noted the cancer diagnosis at 800 (49.5%) cancer patient visits. Naturopathic physicians frequently assigned diagnoses that are used to indicate symptom management. For example, the neurological diagnosis is often use for headaches, female reproductive diagnoses for menopause treatment issues, and the category of general signs and symptoms often indicates debility and undue fatigue.

Table 3
Diagnoses Assigned by Conventional or Complementary and Alternative Medicine Providers*

Among 895 patients receiving chemotherapy, 455 (50.8%) had a diagnosis of nausea/vomiting; 26 (5.7%) visited an acupuncturist (data not shown). For chemotherapy patients the estimated odds of receiving acupuncture were not significantly different for individuals with nausea/vomiting compared to individuals without nausea/vomiting (OR: 1.51 95% CI: 0.81 –2.82). Approximately 3.9% of all study participants’ visits to an acupuncturist were for nausea/vomiting.

The diagnostic codes for lymphedema were present on 240 (15.7%) patients with breast cancer. Of these 29 (12.1%) were treated by a massage therapist and 155 (64.6%) by a physical or occupational therapist. Comparing patients with and without lymphedema, the estimated odds of massage were 58% higher for women with lymphedema (OR: 1.58 95% CI: 1.02 – 2.45). Among women with breast cancer, the odds of visiting a massage therapist are estimated to be 3.71 times higher for those with lymphedema compared to those without. (OR: 3.71 95% CI: 2.78 – 4.94).

Expenditures and Utilization of CAM and Conventional Services by Treatment Phase

Mean per capita expenditures and the relative contribution of selected services for each treatment phase are shown in Figure 1. The least expensive phase for cancer treatment was the continuing phase which we estimated to result in $12,429 of annual expenditures. Expenditures for the initial phase were $38,587 and the most costly interval, the end-of-life phase, resulted in $115,994 per capita expenditures. Inpatient hospital and outpatient provider expenditures for conventional treatments accounted for over 50% of all expenditures during each treatment phase. Expenditures for inpatient and hospice care were proportionately higher at the end-of-life than they were in the other treatment phases. Even though 179 (57.7%) patients who died used hospice at the end-of-life, only 1.6% of end-of-life expenditures were for this service.

Figure 1
Per Capita Expenditures by Services Category* and Treatment Phase

Expenditures for CAM providers were a small portion of overall expenditures as shown in Figure 1. CAM providers accounted for 1% or less of total health care expenditures during all three treatment phases. As a proportion of outpatient provider charges only, CAM services accounted for 1.2%, 3.1% and 0.4% for the initial, continuing, and end-of-life phases respectively (data not shown). CAM outpatient provider expenditures were 1.5% of total outpatient provider expenditures during the entire study period.


Under the Washington State model (where most patients can self-refer for many CAM services) CAM provider visits accounted for only 7.2% of all outpatient provider visits and the associated expenditures were small for each treatment phase when CAM provider expenditures were compared to standard categories of conventional service. CAM providers were a slightly higher proportion of expenditures when outpatient provider charges were evaluated separately. The proportion of cancer patients using CAM provider was similar in each treatment phase indicating that these providers play a consistent role in the cancer patient’s medical care. Because all of our cancer patients were also using conventional providers and CAM provider visits usually resulted in musculoskeletal diagnoses we see no reason to be concerned that CAM providers are replacing necessary conventional care.

Studies of CAM utilization have struggled with the proper metrics by which to describe CAM use for particular medical conditions and specific patient populations. Some surveys of CAM use have been broad in their scope and have included personal practices like prayer as a CAM treatment modality.27, 28 In contrast, we chose a very narrow definition of CAM based on licensed health care providers whose services are required to be available from private, commercial insurance underwritten in Washington State. By doing this, we believe our findings are relevant to third-party payers elsewhere who may be considering integrating a CAM benefit into their health insurance products.

Women seem to be particularly open to using care from alternative providers. In addition, the predominant diagnoses from CAM providers were for musculoskeletal conditions. Back and neck pain, arthritis, and similar disorders are extremely common in the general middle-aged population29, 30 and there is no reason to suspect that cancer patients would escape these difficult to manage and highly prevalent medical conditions. A previous study, using 2000 data on 600,000 privately insured adult (18–64 years) enrollees,19 found musculoskeletal issues to be the most common diagnoses made by both conventional and CAM providers. In that study, chiropractic was used by approximately 11% of the population, acupuncture 1.3%, naturopathic physicians 1.6%, and massage therapists 2.4%. In this current study of cancer care, the proportion of patients using non-chiropractic CAM providers during the initial and continuing treatment phases is substantially higher than what was previously noted in the general enrollee population. This probably indicates that cancer patients use a significant number of all medical services and rely on multiple health care providers to manage pain and discomfort. Management of pain is not optimal for cancer patients and the quality of the science measuring pain relief is often low.31 We will be interested to follow how recent studies of acupuncture for the treatment of functional low-back pain alter patient and provider choices for the management of this condition in patients who have been diagnosed with cancer.32

Our study has several strengths. Our large sample size, consistent definition of CAM, use of claims data, and the registry match eliminate much of the uncertainty that has come from smaller studies using patient survey methodology. Several limitations are also apparent. First, an unknown amount of CAM and conventional care was probably paid for out-of-pocket because not all providers accept insurance. If fewer CAM providers accept insurance than conventional providers, we may have underestimated the role of CAM care. Second, we did not have data on pharmaceutical expenditures that could be accurately stratified by treatment phase. This information would have likely raised the conventional proportion of the total. Third, we are not commenting on the desirability of integrating CAM into conventional systems of health care finance and treatment efficacy cannot be determined by claims analysis. Although many patients use CAM, we do not know from these data the relative value and importance patients place on access to CAM services. Fourth, the significance of some of our estimates may be reflective of small sample sizes (e.g. for acupuncture). Finally, ICD9 coding is generally accurate, but some coding errors may have occurred.

The philosophical underpinnings of what insurance should cover and how it should be used by patients with serious medical conditions, such as cancer, will be important to the CAM health policy debate. In a market-based approach the presence of choices and the willingness to pay for care are potent factors in making coverage decisions. In managed models of integrated care delivery cost-effectiveness analysis may play a greater role in choosing specific coverage strategies. Most medical treatments, CAM and conventional, have no ideal scientific database to guide these important decisions.33, 34

Treatment of all forms of discomfort in cancer patients is an important issue. Because of the consistent role that CAM providers play in the care for cancer patients, future studies should assess the relative importance patients place on access to CAM providers. In addition, studies on the comparative effectiveness of CAM and conventional treatments for the management of cancer patients’ musculoskeletal conditions are warranted.


The authors wish to thank Yuki Durham, MLS for her assistance with references.

Funding Source

This publication was made possible by Grant Number NIH-5 R01- AT03270 from the National Center for Complementary and Alternative Medicine (NCCAM). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the National Center for Complementary and Alternative Medicine, National Institutes of Health

Appendix 1. Definitions of Cancer Therapies

Cancer therapies defined by the presence of these Current Procedural Terminology (CPT)1 codes
Chemotherapy96400, 96405, 96406, 96408, 96410, 96412, 96414, 96420, 96422, 96423, 96425, 96440, 96445, 96450, 96520, 96530, 96542, 96545, 96549, 99555
Radiation therapy/brachytherapy therapy77401, 77402, 77403, 77404, 77406, 77407, 77408, 77409, 77411, 77412, 77413, 77414, 77416, 77417, 77418, 77419, 77420, 77425, 77427, 77430, 77431, 77432, 77470, 77499, 77520, 77522, 77523, 77525, 77750, 77761, 77762, 77763, 77776, 77777, 77778, 77781, 77782, 77783, 77784, 77789, 77790, 77799
Surgery (resection, mastectomy splenectomy, pneumonectomy, lobectomy, wedge resecton, and prostatectomy)00472, 00474, 00546, 00844, 00912, 00914, 00916, 01234, 01482, 01632, 19140, 19160, 19162, 19180, 19182, 19200, 19220, 19240, 21015, 21045, 23077, 23195, 23200, 29862, 29875, 30140, 30520, 31240, 32035, 32440, 32442, 32442, 32445, 32480, 32480, 32482, 32484, 32484, 32486, 32486, 32486, 32488, 32500, 32500, 32500, 32501, 32501, 32501, 32520, 32522, 32525, 32657, 32657, 32659, 32900, 33025, 33120, 33130, 33415, 33476, 33478, 33542, 33545, 33684, 33732, 38100, 38101, 38102, 39560, 39561, 40530, 41150, 41153, 41155, 42120, 42842, 42844, 42845, 42892, 42894, 43860, 43865, 44120, 44121, 44125, 44126, 44127, 44128, 44144, 44202, 44203, 44625, 44626, 44660, 44661, 45111, 45190, 45550, 47120, 47122, 47125, 47130, 48005, 49255, 50220, 50225, 50230, 51050, 51597, 51800, 52234, 52235, 52240, 52277, 52300, 52301, 52305, 52339, 52340, 52347, 52355, 52400, 52500, 52601, 52612, 52614, 52620, 52630, 52640, 52648, 55150, 55801, 55810, 55812, 55815, 55821, 55831, 55840, 55842, 55845, 56348, 56353, 58240, 58560, 58563, 58920, 58950, 58951, 58952, 59136, 61583, 61591, 61597, 61600, 61601, 61605, 61606, 61607, 61608, 61615, 61616, 63081, 63082, 63085, 63086, 63087, 63088, 63090, 63091, 63300, 63301, 63302, 63303, 63304, 63305, 63306, 63307, 63308, 65285, 65775, 67311, 67312, 67314, 67316, 67903, 67904, 67908, 69535, 88305, 88309
1American Medical Association. Current Procedural Terminology. Chicago, IL: The Association, 2002.



Over 26% of cancer patients see CAM providers primarily for musculoskeletal problems. This does not vary by treatment phase. The associated expenditures are low.

Take-away Points

Under a system where CAM providers are covered by insurance, 26.5% of cancer patients will see a licensed alternative provider during the course of their therapy.

The proportion of patients seeing CAM providers does not significantly vary between three treatment phases, initial, continuing, and at end-of-life.

Most cancer patients will have a musculoskeletal diagnosis during the course of their therapy and the vast majority of CAM visits are associated with musculoskeletal diagnoses.

Expenditures for CAM services are a small proportion of overall expenditures.

Contributor Information

William E. Lafferty, Professor, Department of Health Services, School of Public Heath and Community Medicine, University of Washington.

Patrick T. Tyree, Research Consultant, Department of Health Services, School of Public Heath and Community Medicine, University of Washington.

Sean M. Devlin, Research Associate, Department of Biostatistics, School of Public Heath and Community Medicine, University of Washington.

M. Robyn Andersen, Associate Member, Translational Outcomes Research Group, Fred Hutchinson Cancer Research Center, Affiliate Assistant Professor, Department of Health Services, School of Public Heath and Community Medicine, University of Washington.

Paula K. Diehr, Professor, Department of Biostatistics, School of Public Heath and Community Medicine, University of Washington.


1. Minino AM, Heron MP, Smith BL. Deaths: preliminary data for 2004. Natl Vital Stat Rep. 2006;54(19):1–49. [PubMed]
2. American Cancer Society. Cancer Facts & Figures. American Cancer Society; 2007.
3. Yabroff KR, Warren JL, Brown ML. Costs of cancer care in the USA: a descriptive review. Nat Clin Pract Oncol. 2007;4(11):643–56. [PubMed]
4. Yabroff KR, Davis WW, Lamont EB, et al. Patient time costs associated with cancer care. J Natl Cancer Inst. 2007;99(1):14–23. [PubMed]
5. Patterson RE, Neuhouser ML, Hedderson MM, et al. Types of alternative medicine used by patients with breast, colon, or prostate cancer: predictors, motives, and costs. J Altern Complement Med. 2002;8(4):477–85. [PubMed]
6. Ezzo JM, Richardson MA, Vickers A, et al. Acupuncture-point stimulation for chemotherapy-induced nausea or vomiting. Cochrane Database Syst Rev. 2006;(2):CD002285. [PubMed]
7. Weiger WA, Smith M, Boon H, Richardson MA, Kaptchuk TJ, Eisenberg DM. Advising patients who seek complementary and alternative medical therapies for cancer. Ann Intern Med. 2002;137(11):889–903. [PubMed]
8. Berman BM, Lao L, Langenberg P, Lee WL, Gilpin AM, Hochberg MC. Effectiveness of acupuncture as adjunctive therapy in osteoarthritis of the knee: a randomized, controlled trial. Ann Intern Med. 2004;141(12):901–10. [PubMed]
9. Lafferty WE, Downey L, McCarty RL, Standish LJ, Patrick DL. Evaluating CAM treatment at the end of life: a review of clinical trials for massage and meditation. Complement Ther Med. 2006;14(2):100–12. [PubMed]
10. Cherkin DC, Sherman KJ, Deyo RA, Shekelle PG. A review of the evidence for the effectiveness, safety, and cost of acupuncture, massage therapy, and spinal manipulation for back pain. Ann Intern Med. 2003;138(11):898–906. [PubMed]
11. Lind BK, Lafferty WE, Tyree PT, Sherman KJ, Deyo RA, Cherkin DC. The role of alternative medical providers for the outpatient treatment of insured patients with back pain. Spine. 2005;30(12):1454–9. [PubMed]
12. Lafferty WE, Bellas A, Corage Baden A, Tyree PT, Standish LJ, Patterson R. The use of complementary and alternative medical providers by insured cancer patients in Washington State. Cancer. 2004;100(7):1522–30. [PubMed]
13. Kim SP, Feinglass J, Bennett CL, et al. Merging claims databases with a tumor registry to evaluate variations in cancer mortality: results from a pilot study of 698 colorectal cancer patients treated at one hospital in the 1990s. Cancer Invest. 2004;22(2):225–33. [PubMed]
14. Keating NL, Landrum MB, Meara E, Ganz PA, Guadagnoli E. Managed care market share and primary treatment for cancer. Health Serv Res. 2006;41(1):9–22. [PMC free article] [PubMed]
15. Eisenberg DM, Kessler RC, Foster C, Norlock FE, Calkins DR, Delbanco TL. Unconventional medicine in the United States. Prevalence, costs, and patterns of use. N Engl J Med. 1993;328(4):246–52. [PubMed]
16. Cooper RA. Health care workforce for the twenty-first century: the impact of nonphysician clinicians. Annu Rev Med. 2001. pp. 51–61. Available from [PubMed]
17. Sturm R, Unutzer J. State legislation and the use of complementary and alternative medicine. Inquiry - Blue Cross and Blue Shield Association. 20002001;37(4):423–30.
18. Watts CA, Lafferty WE, Baden AC. The effect of mandating complementary and alternative medicine services on insurance benefits in Washington State. J Altern Complement Med. 2004;10(6):1001–8. [PubMed]
19. Lafferty WE, Tyree PT, Bellas AS, et al. Insurance coverage and subsequent utilization of complementary and alternative medicine providers. Am J Manag Care. 2006;12(7):397–404. [PMC free article] [PubMed]
20. Tyree PT, Lind BK, Lafferty WE. Challenges of using medical insurance claims data for utilization analysis. Am J Med Qual. 2006;21(4):269–75. [PMC free article] [PubMed]
21. Buchanan RJ, Bolin J, Wang S, Zhu L, Kim M. Urban/rural differences in decision making and the use of advance directives among nursing home residents at admission. J Rural Health. 2004;20(2):131–5. [PubMed]
22. Johns Hopkins University. The Johns Hopkins Adjusted Clinical Groupings Case-Mix System. 8. Baltimore: Johns Hopkins University; 2006.
23. CPI Detailed Report: Data for October 2007. Office of Prices and Living Conditions. Bureau of Labor Statistical; Washington DC: 2007.
24. American Medical Association. Current Procedural Terminology. Chicago, IL: The Association; 2002.
25. Hankey BF, Ries LA, Edwards BK. The surveillance, epidemiology, and end results program: a national resource. Cancer Epidemiol Biomarkers Prev. 1999;8(12):1117–21. [PubMed]
26. StataCorp. Stata Statistical Software: Version 9.2. College Station, TX: Stata Corporation; 2006.
27. Kaptchuk TJ, Eisenberg DM. Varieties of healing. 2: a taxonomy of unconventional healing practices. Ann Intern Med. 2001;135(3):196–204. [PubMed]
28. Gray CM, Tan AW, Pronk NP, O’Connor PJ. Complementary and alternative medicine use among health plan members. A cross-sectional survey. Eff Clin Pract. 2002;5(1):17–22. [PubMed]
29. Eubanks JD, Lee MJ, Cassinelli E, Ahn NU. Prevalence of lumbar facet arthrosis and its relationship to age, sex, and race: an anatomic study of cadaveric specimens. Spine. 2007;32(19):2058–62. [PubMed]
30. Gourmelen J, Chastang JF, Ozguler A, Lanoe JL, Ravaud JF, Leclerc A. Frequency of low back pain among men and women aged 30 to 64 years in France. Results of two national surveys. Ann Readapt Med Phys. 2007;50(8):640–44. [PubMed]
31. Carr DB, Goudas LC, Balk EM, Bloch R, Ioannidis JP, Lau J. Evidence report on the treatment of pain in cancer patients. J Natl Cancer Inst Monogr. 2004;(32):23–31. [PubMed]
32. Haake M, Muller HH, Schade-Brittinger C, et al. German Acupuncture Trials (GERAC) for chronic low back pain: randomized, multicenter, blinded, parallel-group trial with 3 groups. Arch Intern Med. 2007;167(17):1892–8. [PubMed]
33. Dubinsky M, Ferguson JH. Analysis of the National Institutes of Health Medicare coverage assessment. Int J Technol Assess Health Care. 1990;6(3):480–8. [PubMed]
34. O’Reilly J, Dalal A. Off-label or out of bounds? Prescriber and marketer liability for unapproved uses of FDA-approved drugs. Ann Health Law. 2003;12(2):295–324. table of contents. [PubMed]