Estimation of the Period Prevalence of Inflammatory Bowel Disease Among Nine Health Plans Using Computerized Diagnoses and Outpatient Pharmacy Dispensings

Harvard University, Cambridge, Massachusetts, United States
Inflammatory Bowel Diseases (Impact Factor: 4.46). 04/2007; 13(4):451-61. DOI: 10.1002/ibd.20021
Source: PubMed

ABSTRACT There are few contemporary estimates of prevalence rates for inflammatory bowel disease (IBD) in diverse North American communities.
We estimated the period prevalence of IBD for January 1, 1999, through June 30, 2001, among 1.8 million randomly sampled members of nine integrated healthcare organizations in the US using computerized diagnoses and outpatient pharmaceutical dispensing. We also assessed the positive predictive value (PPV) and sensitivities of 1) the case-finding algorithm, and 2) the 30-month sampling period using medical chart review and linkage to a 78-month dataset, respectively.
The PPV of the case-finding algorithm was 81% (95% confidence interval [CI], 78-87) and 84% (95% CI, 79-89) in two different organizations. In both, the sensitivity of the optimal algorithm, compared with the most inclusive, exceeded 90%. The sensitivity of the 30-month sampling period compared with 78 months was 61% (95% CI, 57-64) in one organization. Applying a slightly more sensitive case-finding algorithm, the average period prevalence of IBD across the nine organizations, standardized to the age- and gender-distribution of the US population, 2000 census, was 388 cases (95% CI, 378-397) per 100,000 persons (range 209-784 per 100,000; average follow-up 26 months). The prevalence of Crohn's disease, ulcerative colitis, and unspecified IBD was 129, 191, and 69 per 100,000, respectively.
The observed average prevalence was similar to prevalence proportions reported for other North American populations (369-408 per 100,000). Additional research is needed to understand differences in the occurrence of IBD among diverse populations as well as practice variation in diagnosis and treatment of IBD.

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    • "Epidemiological studies of IBD in the USA are necessary to quantify the public health burden of disease and inform policy regarding the allocation of resources and provision of health services for affected individuals. Because IBD is not a reportable condition in the USA and comprehensive, nationwide registries for IBD surveillance have not been established, published studies on the epidemiology of IBD in the USA [1–6] are limited and primarily include studies which have sampled small, geographically restricted populations. Furthermore, no studies of IBD prevalence have been published using data from the last 5 years and, therefore, current time trends remain unknown. "
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    ABSTRACT: Purpose Most US inflammatory bowel disease (IBD) epidemiology studies conducted to date have sampled small, geographically restricted populations and have not examined time trends. The aim of our study was to determine the prevalence of Crohn’s disease (CD) and ulcerative colitis (UC) in a commercially insured US population and compare prevalences across sociodemographic characteristics and time. Methods Using claims data from approximately 12 million Americans, we performed three consecutive 2-year cross-sectional studies. Cases of CD and UC were identified using a previously described algorithm. Prevalence was estimated by dividing cases by individuals in the source population. Logistic regression was used to compare prevalences by region, age, and sex. Results In 2009, the prevalences of CD and UC in children were 58 [95 % confidence interval (CI) 55–60] and 34 (95 % CI 32–36), respectively. In adults, the respective prevalences were 241 (95 % CI 238–245) and 263 (95 % CI 260–266). Data analysis revealed that IBD prevalences have slightly increased over time. Based on census data, an estimated 1,171,000 Americans have IBD (565,000 CD and 593,000 UC). Conclusions Analysis of the epidemiological data revealed an increasing burden of IBD in recent years, which may be used to inform policy.
    Digestive Diseases and Sciences 08/2012; 58(2). DOI:10.1007/s10620-012-2371-5 · 2.61 Impact Factor
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    • "Validation studies for chronic diseases have also been published [16,17]. These generally, though implicitly, are studies of disease prevalence rather than incidence. "
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    ABSTRACT: Osteonecrosis (ON) is a rare disease associated with alcohol and glucocorticoid use. Identifying additional risk factors is difficult as the number of cases at any single center is small. We investigated whether data available in large health care databases can be used to identify incident ON cases. Using data from the Boston Veterans Affairs Healthcare system, we identified potential cases of ON. These records, including available radiographs and reports, were reviewed. Using published criteria, we evaluated whether the subjects had confirmed ON (radiographs/reports met criteria), incident ON (onset of symptoms within 6 months of first code), or prevalent ON (onset more than 6 months prior to first code or onset could not be determined). We tested different definitions for incident ON using information derived from administrative data. These were compared to the 'gold standard' (record review) and positive predictive values (PPVs) were derived. Since PPVs for incident cases were low, we found the number of incident cases expected for every 1,000 potential cases identified, using the definitions as an initial screening tool to reduce the number of medical records that required examination. We identified 87 potential cases. No case of jaw ON was identified. Only 15 (17%) incident cases of ON were identified. PPVs never exceed 50% for incident ON. However, if we used the definition '(at least 1 inpatient ON code) and (no prior codes for osteoarthritis)' as an initial screen, then for every 1,000 records, we would need to review only 150 to find 69 incident cases. Though the precise PPVs we found may not be generalizable to other databases, we believe that administrative data alone should not be used to identify incident cases of ON without confirming the diagnosis through a review of medical records. By applying the above definition, the number of records requiring review can be markedly reduced. This method can be used to find cases for valid case-control studies of risk factors for ON.
    Arthritis research & therapy 07/2009; 11(3):R89. DOI:10.1186/ar2731 · 3.75 Impact Factor
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    ABSTRACT: Guidelines for clinical practice are intended to indicate preferred approaches to medical problems as established by scientifically valid research. Double-blind placebo-controlled studies are preferable, but compassionate use reports and expert review articles are utilized in a thorough review of the literature conducted through Medline with the National Library of Medicine. When only data that will not withstand objective scrutiny are available, a recommendation is identified as a consensus of experts. Guidelines are applicable to all physicians who address the subject without regard to the specialty training or interests and are intended to indicate the preferable but not necessarily the only acceptable approach to a specific problem. Guidelines are intended to be flexible and must be distinguished from standards of care, which are inflexible and rarely violated. Given the wide range of specifics in any health-care problem, the physician must always choose the course best suited to the individual patient and the variables in existence at the moment of decision. Guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee and approved by the Board of Trustees. Each has been extensively reviewed and revised by the Committee, other experts in the field, physicians who will use them, and specialists in the science of decision of analysis. The recommendations of each guideline are therefore considered valid at the time of their production based on the data available. New developments in medical research and practice pertinent to each guideline will be reviewed at a time established and indicated at the publication in order to assure continued validity.
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