Complication rate for hip/knee replacement patients
The hip/knee replacement complication rate is an estimate of complications within an applicable time period, for patients electively admitted for primary total hip and/or knee replacement. Medicare measures the likelihood that at least 1 of 8 complications occurs within a specified time period:
- Heart attack (acute myocardial infarction [AMI]), pneumonia, or sepsis/septicemia/shock during the index admission or within 7 days of admission;
- Surgical site bleeding, pulmonary embolism, or death during the index admission or within 30 days of admission; or
- Mechanical complications or periprosthetic joint infection/wound infection during the index admission or within 90 days of admission.
Medicare chose to measure these complications within the specified times because complications over a longer period may be impacted by factors outside the hospitals’ control like other complicating illnesses, patients’ own behavior, or other care services patients received after they leave the hospital. This measure is separate from the serious complications measure (also reported on Hospital Compare).expand
Which patients are included
The hip/knee replacement complication rate includes Medicare beneficiaries 65 or older who were electively admitted for hip/knee replacement and enrolled in Original Medicare (traditional fee-for-service Medicare) for the entire 12 months prior to their hospital admission. Beneficiaries enrolled in Medicare managed care plans aren't included.
The statistical model used to calculate the complication rate also determines how precise the estimates are, and provides the upper and lower bounds of the 95% interval estimates for each hospital’s risk-adjusted complication rate. Interval estimates, which are like confidence intervals, describe the level of uncertainty around the estimated complication rates.
Comparing individual hospital rates to the national rate
To assign complication performance categories, the hospital’s interval estimate is compared to the national complication rate. The table below describes the performance categories and classification criteria in detail:
|Complication Measure Performance Categories|
|Category||Better than the national rate||No different than the national rate||Worse than the national rate||The number of cases is too small|
|Criterion||The entire 95% interval estimate surrounding the hospital’s rate is lower than the national rate.||The 95% interval estimate surrounding the hospital’s rate includes the national rate.||The entire 95% interval estimate surrounding the hospital’s rate is higher than the national rate.||Fewer than 25 cases|
For more detail on how the hip/knee replacement complication rates are calculated, please refer to QualityNet – complication measures - Opens in a new window Exit Disclaimer - Opens in a new window. For other questions regarding hip/knee complication measures, please email firstname.lastname@example.orgExit Disclaimer - Opens in a new window