Januel et al report findings of a systematic review and meta-analysis to estimate the total incidence of acute symptomatic venous thromboembolism (symptomatic DVT or pulmonary embolism) among patients receiving proper thromboprophylaxis after hip or knee replacements.
They came up with rates of 1.1% after knee replacements, and 0.5% after hip replacements. The rate of pulmonary embolism was only 0.27%. Pretty good.
However, as the accompanying editorial by John Heit points out, much of the risk of DVT / PE after joint replacement surgery comes after hospital discharge, which is why thromboprophlaxis is continued at home for weeks during convalescence and physical therapy. Without that data, you can't say much that's useful to a patient or policymaker.
Authors argue their data could be used to establish quality benchmarks/metrics for in-hospital care. But the typical "compartmentalization" of this study highlights a fundamental disconnect in health services research today (and health care in general): these outcomes, and outcomes in general, should be studied over human timespans (entire episode of illness and recovery), not administrative ones (time in an ICU, time in the hospital). These fragments of information may be interesting to those of us who spend our careers in those areas, but when considered separately, mean little to the people passing through on their way to recovery.
Januel J-M et al. Symptomatic In-Hospital Deep Vein Thrombosis and Pulmonary Embolism Following Hip and Knee Arthroplasty Among Patients Receiving Recommended Prophylaxis. JAMA 2012;307(3):294-303.