The study was conducted in co-operation with a German sickness fund to identify determinants of disease-specific health outcomes after hip surgery in routine health care.
In September 1997 all beneficiaries (age 40-75 yrs.), who were hospitalized for "osteoarthrosis" (ICD 9-715/820), were sent a disease-specific survey instrument on average 5.2 months (T1) after discharge. Survey content focused, among others, on pre- and postoperative symptoms and impairment (Lequesne index), postoperative complications, comorbidity (Katz Index) and health-related quality of life (SF-36). The response rate at T1 was 67.8%. Only patients undergoing hip surgery were sent a second survey instrument 17.2 months (T2) after discharge. After two mailings, data from 293 patients were available for analysis. Descriptive and multivariate analysis (GSK Model) were performed.
Patients (57.6% male) were on average 61 yrs. of age and 61.2% reported no comorbidity. 88.4% received total hip replacement. A third of patients reported at least one complication. Univariate, a substantial (and highly significant) improvement was found for the Lequesne Index over time: (recalled) preoperative: 14.2 points; postoperative T1: 5.6 pts.; postoperative T2: 4.4 pts. This result is confirmed by multivariate analyses (estimated values: pre = 13.8, T1 = 6.9; T2 = 5.7), although it is modified by an interaction effect between the variables "Lequesne index" and "complication". The Lequesne Index in patients with complications is estimated preoperative 12.9, at T1 = 7.3 and T2 = 6.2. The respective estimated values for patients without complications are: preoperative 14.7, T1 = 6.5, T2 = 5.2.
Patients with postoperative complications obtain lower scores on the Lequesne Index (higher burden of disease) before hip surgery. Their postoperative progress is slower in the short term (-5.6 pts. vs. -8.2 pts) and in the medium term (-6.7 pts. vs. -9.5 pts). Complications after hip surgery have a lasting negative effect on disease-specific health outcomes.