Context
Total hip arthroplasty (THA) is a common surgical procedure but little is known about longitudinal trends.
Objective
To examine demographics and outcomes of patients undergoing primary and revision THA between 1991 and 2008.
Design, Setting, and Participants
Observational cohort of 1,453,493 Medicare beneficiaries who underwent primary THA and 348,596 who underwent revision THA.
Outcomes
Changes in patient demographics and comorbidity; hospital length of stay (LOS); mortality; discharge disposition; and all-cause readmission rates.
Results
Between 1991 and 2008 the mean age for primary THA increased from 74.1 (95% CI, 74.0-74.1) years to 75.1 (95% CI, 75.1-75.2)(P=0.01) and 75.8 (95% CI, 75.7-75.9) to 77.3 (95% CI, 77.2-77.4) for revision THA (P<.001). The mean number of comorbid illnesses per patient increased from 1.0 (95% CI, 1.0-1.0) to 2.0 (95% CI, 2.0-2.0) for primary and 1.1 (95% CI, 1.1-1.1) to 2.3 (95% CI, 2.3-2.3) for revision THA (P<.001 for both). For primary THA, LOS decreased from 9.1 days (95% CI, 9.1-9.2) in 1991–1992 to 3.7 days (95% CI, 3.7-3.7) in 2007–2008 (P=0.002); unadjusted in-hospital and 30-day mortality decreased from 0.5% (95% CI, 0.5%-0.5%) to 0.2% (95% CI, 0.2%-0.2%)(P< 0.001) and 0.7% (95% CI, 0.7%-0.7%) to 0.4% respectively (95% CI, 0.4%-0.4%)(P< 0.001). The proportion of primary THA patients discharged home declined from 68.0% (95% CI, 67.8%-68.3%) to 48.2% (95% CI, 48.0%-48.4%)(P<.001); the proportion discharged to skilled care increased from 17.8% (95% CI, 17.6%-18.1%) to 34.3% (95% CI, 34.1%-34.5%) (P<.001); 30-day all-cause readmission increased from 5.9% (95% CI, 5.8%-6.1%) to 8.5% (95% CI, 8.4%-8.6%) (P<.001). For revision THA similar trends were observed in hospital LOS, in-hospital mortality, discharge disposition, and hospital readmission rates.
Conclusions
Among Medicare beneficiaries who underwent primary and revision hip arthroplasty between 1991 and 2008, there was a decrease in hospital LOS, but an increase in the rates of post-acute care and readmission.