Elective total hip replacement: incidence, emergency readmission rate, and postoperative mortality

Abstract

Objectives: To report the incidence of elective total hip replacement and postoperative mortality, emergency readmission rates, and the demographic factors associated with these rates in a large defined population.

Design: Analysis of linked, routine abstracts of hospital inpatient records and death certificates.

Setting: 10 hospitals in six districts in Oxford Regional Health Authority covered by the Oxford record linkage study.

Subjects: Records for 11,607 total hip replacements performed electively in 1976-85.

Main outcome measures: Incidence of operation, postoperative mortality, relative mortality ratios, and incidence of emergency readmission.

Results: NHS operation rates increased over time from 43 to 58 operations/100,000 population. Variation in operation rates between districts reduced over time. Operation rates were on average 25% higher in women than men. There were 93 deaths (11/1000 operations) within 90 days of the operation and 208 emergency readmissions (28/1000 operations) within 28 days of discharge. Postoperative mortality and emergency readmission rates increased with age. No significant trend with time was found. Mortality in the 90 days after the operation was 2.5-fold higher (1.9 to 3.0) than in the rest of the first postoperative year. This represented an estimated excess of 6.5 (4.2 to 8.8) early postoperative deaths/1000 operations. Most deaths were ascribed to cardiovascular events. Thromboembolic disease was the commonest reason for emergency readmission.

Conclusions: The pronounced increase in operations in districts with initially low rates suggests a trend towards greater equity in the local provision of NHS hip arthroplasty. The early postoperative clusters of deaths attributed to cardiovascular disease and of readmissions for thromboembolic disease suggest that there is scope for investigating ways of reducing the incidence of major adverse postoperative events.