Abstract
Study Purpose
Administrative databases are commonly used to examine use of healthcare service, with researchers relying on diagnostic codes to identify medical conditions. This study evaluates the accuracy of administrative claims in identifying Parkinsonism cases compared to the selfโreported Parkinson's disease (PD).
Methods
The reference cases were identified based on the selfโreported PD status and the use of PD drugs collected by the 1992โ2000 Medicare Current Beneficiary Survey that contained 72,922 observations from 30,469 individuals. Using ICDโ9 CM, cases with PD were extracted from the corresponding Medicare claims. We compared prevalence of PD obtained using different types of claims.
Results
The sensitivities were the highest when all claims were used (66%). All the specificities were greater than 99%. When drug use information was included in the gold standard, the sensitivities became lower, while the specificities and positive predictive values (PPVs) increased. Using more diagnostic codes improved the sensitivity of the identification process but reduced PPVs.
Conclusions
Administrative claims can provide fairly accurate and practical approach to โrule inโ patients with PD. Depending on the purpose of evaluation, researchers may consider using more categories of claims to improve the sensitivity of the identification algorithm or use fewer diagnoses to minimize number of false positive cases. ยฉ 2006 Movement Disorder Society