CONCORDANCE OF MEDICARE DATA AND POPULATION-BASED CLINICAL-DATA ON CATARACT-SURGERY UTILIZATION IN OLMSTED COUNTY, MINNESOTA

The authors assessed concordance of local Medicare health care utiliza tion data on cataract surgery and estimates generated using the databa ses of the Rochester Epidemiology Project, which capture virtually all medical care received by residents of Olmsted County, Minnesota. The Rochester Project databases identified 1,353 primary cataract extracti ons performed in Olmsted County between October 1989 and December 1993 among county residents aged greater than or equal to 65 years. Medica re data identified 1,148 claims-84.8% of the number of procedures iden tified by the Rochester Project. Ratios of numbers of encounters (Medi care/Rochester Project) were 189/350 (0.540) for 1992 versus 959/1,003 (0.956) for the other years combined. Changes in Medicare data file t ransfer procedures may have produced the 1992 data shortfall. Medicare data should periodically be compared with source data to assess conco rdance.