ACCURACY OF ADMINISTRATIVE DATA FOR ASSESSING OUTCOMES AFTER KNEE REPLACEMENT SURGERY

Objective: To assess the accuracy of information in an administrative database (Canadian Institute for Health Information; CIHI) compared wi th the hospital record for patients undergoing knee replacement (KR). Methods: A stratified random sample of 185 KR recipients from 5 Ontari o hospitals were chosen. Their hospital records and corresponding CIHI files were compared to assess percent complete agreement, false negat ive (FN) and false positive (FP) rates for demographic data, procedure s, and diagnoses. Results: Of 185 records, 175 (95%) were reviewed. Pe rcent complete agreement was greater than 94% for each of patient demo graphics and procedures (mean FN rates: 0%; mean FP rates: 0-5%). For comorbidities and complications, although mean percent complete agreem ent was high, and FP rates were low, mean FN rates were 63% for specif ic comorbid conditions and 70% for organ systems. Conclusions: High FN rates have been found in documentation of comorbidities and in hospit al complications for CIHI data compared with the hospital record. Unde r-coding of comorbidities and in hospital complications has potential implications for researchers using administrative databases. (C) 1997 Elsevier Science Inc.