Assessing the quality of pharmacological treatments from administrative databases: the case of low-molecular-weight heparin after major orthopaedic surgery.

Rationale, Aims And Objectives: 'Real world data' are needed to assess the quality of pharmacological treatments in clinical practice. The aim of this study was to determine whether administrative databases can be used to assess the quality of prophylaxis with low-molecular-weight heparin after major orthopaedic surgery.

Methods: The study was performed in a Belgian university hospital. Patients undergoing total hip replacement (THR), total knee replacement (TKR) or hip fracture surgery (HFS) were selected retrospectively from the hospital's 2002 and 2003 administrative databases. Readmissions during the same year as the procedure were also analysed. Three quality indicators were assessed: incidence of venous thromboembolism (VTE), major bleeding and death; adherence to guidelines; and the costs of care.

Results: Although 70% of data were collected from administrative databases, patients' records also had to be examined. During the period studied, VTE and major bleeding events were rare. Patients undergoing HFS were at greater risk of having a pulmonary embolism [Exact odds ratio (OR)=3.78; 95% confidence interval (CI)=1.13-16.22; P=0.03] or of death from any cause (Exact OR=2.15; 95% CI=1.52-infinity; P<0.01) than patients undergoing THR or TKR. The hospital's prophylaxis protocol was not always followed. Half the patients received higher prophylaxis doses than recommended and 11% received lower doses but no impact on adverse events was demonstrated.

Conclusion: Results show that administrative databases contain enough information to measure the frequency of adverse events but complementary data on patient weight and on non-reimbursed drugs must be extracted from the patients' records to evaluate adherence to guidelines. Our findings stress the need for better integration of information systems.