Concordance between patient self-reports and claims data on clinical diagnoses, medication use, and health system utilization in Taiwan

Purpose: The aim of this study was to evaluate the concordance between claims records in the National Health Insurance Research Database and patient selfreports on clinical diagnoses, medication use, and health system utilization. Methods: In this study, we used the data of 15,574 participants collected from the 2005 Taiwan National Health Interview Survey. We assessed positive agreement, negative agreement, and Cohen's kappa statistics to examine the concordance between claims records and patient self-reports. Results: Kappa values were 0.43, 0.64, and 0.61 for clinical diagnoses, medication use, and health system utilization, respectively. Using a strict algorithm to identify the clinical diagnoses recorded in claims records could improve the negative agreement; however, the effect on positive agreement and kappa was diverse across various conditions. Conclusion: We found that the overall concordance between claims records in the National Health Insurance Research Database and patient self-reports in the Taiwan National Health Interview Survey was moderate for clinical diagnosis and substantial for both medication use and health system utilization. ? 2014 Wu et al.