Setting
Data were derived from the Managing Abdominal Pain Study [14], which was carried out in 2001–2002 at Group Health Cooperative of Puget Sound, a 525,000 member health maintenance organization (HMO) in Seattle. The study surveyed patients in the care of 353 primary care physicians and 16 gastroenterology specialists in the HMO.
Design
This study was a part of a larger investigation of standard medical care for FBDs which has been described elsewhere [5]. To identify patients with FBD, all patient encounter forms submitted by primary care and gastroenterology clinic physicians were prospectively screened for IBS (ICD-9CM code 564.1), abdominal pain (789.X), constipation (564.0), or diarrhea (787.91). This process identified patients soon after they had consulted for diagnosis and treatment of a GI complaint: This was their index visit. Patients who met inclusion criteria were mailed an invitation to participate in the study, an informed consent statement, consent to review their medical records (to exclude anyone with subsequent diagnosis of organic disease) and the first set of questionnaires, usually within two weeks of their index visit. A second set of questionnaires was sent 6 months later. Subjects were offered a $10 incentive for completing each of the surveys. This study was reviewed and approved by the institutional review boards of Group Health Cooperative, the University of Washington, and the University of North Carolina at Chapel Hill.
CAM use and costs
Six months after the index visit, participants were asked about CAM use and cost in the previous 3 months. Recall was limited to 3 months because memory is unreliable beyond 3 months [15]. Cost was defined as out-of-pocket expenditures within the last three months, in $10 increments from $10 to $100 (the highest possible response was $100 and over). CAM therapies listed were ginger root or tea, fennel seed, senna tea, psychotherapy, homeopathic, hypnotherapy, massage therapy, biofeedback, acupuncture, yoga, aromatherapy, and evening primrose oil. Patients were also asked to write in any other alternative or home therapy they were using in addition to those listed in the questionnaire. Physician recommendation to see a CAM provider was assessed at the index visit by patient report, and percentage adherence to those recommendations (ranging from 0%–100% in 10% increments) was assessed at the six month follow-up.
In the same questionnaire, subjects were asked about non-prescription medication and supplement use including acid reducers, laxatives, anti-diarrheal medications, stool softeners, gas relief medication, pain medication, anti-spasmodics, fiber, bran, castor oil packs, enemas, suppositories, and electric heating pads or water bottles.
Treatment effectiveness
Treatment effectiveness for prescription medications, non-prescription medications and herbal remedies was measured by self-ratings on a 5 point scale (not at all, a little, somewhat, very, and extremely). Percentage satisfaction with physician care at the index visit was recorded. Symptom improvement at 6 month follow-up was measured in two ways: (1) change in symptoms since index visit rated on a 7 point scale (markedly worse, somewhat worse, a little bit worse, no change, a little better, somewhat better, markedly better) and; (2) patients report of satisfactory relief of bowel symptoms in past 7 days (yes/no) [16].
IBS severity and type
The Irritable Bowel Syndrome Severity Scale (IBS-SS) was used at the index visit. The IBS-SS [17] is a well-validated questionnaire for determining the overall severity of IBS symptoms. Predominant bowel activity type was determined by a single survey question: "In the last 6 months, would you describe your usual bowel movements as...?" The response options were "normal", "mostly diarrhea", "mostly constipation" or "changes back and forth".
Psychological Distress and Quality of Life
Quality of life was assessed with the Irritable Bowel Syndrome Quality of Life Scale (IBS-QoL) [18]. This is a 34-item disease-specific quality of life measure for IBS, which has high internal consistency and reproducibility and has been shown to be responsive to changes in IBS symptom severity.
Psychological symptoms were assessed with the Brief Symptom Inventory-18 (BSI) [19]. This questionnaire quantifies the symptoms of depression, anxiety and somatization over the previous 7 days, and also provides a global severity index reflecting overall psychological distress. Due to the survey nature of this study, a slightly modified version of the BSI was used that omitted one question inquiring about suicidal thoughts, and the scores were pro-rated accordingly.
Administrative claims
Administrative claims at the HMO were reviewed for various categories of direct costs of care for 12 months prior to the index visit and 12 months after the index visit. Additional information on the cost components can be found in a separate report on this study [5]. For each cost category, lower gastrointestinal (GI) costs were recorded separately from overall GI and non-GI costs. Health care costs were categorized as lower GI based on a list of diagnoses, drug classes, and diagnostic procedures designated by co-author Andrew Feld, MD, Chief of Gastroenterology Services for Group Health Cooperative, prior to extracting the administrative claims data. This list is available upon request.
Data analyses
Almost all cost data deviated significantly from a normal distribution, with strong positive skew and kurtosis. Moreover, cost estimates for CAM therapies and other out-of-pocket expenditures were truncated, since the maximum reportable cost for a 3-month period was "$100 or more". In the latter case, we used $100 for this category. Medians and ranges are reported for all patients with FBD and for the subset of patients who reported using CAM therapies. Chi-square tests were used to test for differences across FBD groups in prevalence of CAM use.
Differences between CAM and non-CAM users in demographics, IBS symptoms, psychological distress and quality of life were determined by t-tests because these variables are normally distributed. Logistical regression analysis was run with CAM use as the dependent variable and all variables that showed significant univariate associations with CAM use as independent variables. Non-parametric Spearman correlations were used to determine the association of CAM costs with other health care expenditures and other patient characteristics, to address the non-normal distribution of the cost data. Alpha was .01 for all comparisons.