Comparability between the rates for all-listed inpatient procedures using National Hospital Discharge Survey and Medicare claims, 1999 and 2007.

OBJECTIVES: This report examines the comparability between the rates of inpatient procedures for persons aged 65 and over using the National Hospital Discharge Survey (NHDS) and Medicare claims data.
METHODS: The estimates in this report are based on data from NHDS and Medicare claims submitted by hospital providers for inpatient stays among Part A fee-for-service Medicare beneficiaries aged 65 and over. The discharge rates, selected procedures rates, and comparability ratios are reported for older men and women, by age and sex, for 1999 and 2007.
RESULTS: Between 1999 and 2007, observed decreases in discharge rates and in all-listed procedure rates derived from NHDS were not significant, while Medicare discharge rates decreased and procedure rates increased significantly. In 1999 and 2007, no statistically significant differences were found between NHDS and Medicare estimates for discharge rates in the age-sex groups examined except for those aged 85 and over. In both years, the comparability ratios between Medicare and NHDS procedure rates were significantly different from one for about 50% of selected procedures, and ranged from 1.12 to 1.26 in 1999 and from 1.16 to 1.41 in 2007. This reflects more procedures recorded in 1999 and 2007 in Medicare data per discharge. The comparability ratio was higher for most of the cardiac procedures, and in general, was closer to one when fewer procedures were performed per discharge and for procedures with lower utilization rates.