The accuracy of Medicare's hospital claims data: progress has been made, but problems remain.

• DOI: 10.2105/ajph.82.2.243
• Publication Date: 2008-11-29T13:17:08Z
• Authors: E S Fisher; F S Whaley; W M Krushat; D J Malenka; C Fleming; J A Baron; D C Hsia
• Keywords: Medical record; Diagnosis code; Medical classification

Health care databases provide a widely used source of data for health research, but their accuracy remains uncertain. We analyzed from the 1985 National DRG Validation Study, which carefully reabstracted and reassigned ICD-9-CM diagnosis procedure codes national sample 7050 medical records, to determine whether coding had improved since Institute Medicine studies 1970s assess current specific diagnoses procedures.We defined agreement as proportion all records that same principal or coded on both original (hospital) record record. also evaluated in using concepts diagnostic test evaluation.Overall, percentage between hospital record, when at third digit, 73.2% 1977 78.2% 1985. However, analysis demonstrated varies substantially across conditions.Although some major surgical procedures we examined were accurately coded, variability poses problem must be overcome if claims-based research is achieve its full potential.