Hip Fracture Outcome: Is There a "July Effect?"

We assessed the differential complications and mortality rates of teaching versus nonteaching hospitals in July against other month-to-month differences in a cohort of 324,988 elderly patients hospitalized for a femoral neck or intertrochanteric fracture (data taken from the 1998–2003 National Inpatient Sample). Demographics were similar between teaching and nonteaching hospitals and across admission months. The overall mortality rate was 3.64% and was slightly higher in teaching hospitals compared with nonteaching hospitals (3.69% vs. 3.61%, relative risk [RR] = 1.0062, 95% CI 0.99-1.02). The adjusted relative risk (RR) for mortality in July/August was significantly higher than the overall adjusted RR and compared with all other month pairs, indicating higher in- hospital mortality rates in teaching hospitals compared with nonteaching hospitals. Intraoperative complications and length of stay were statistically significantly greater in teaching hospitals but did not demonstrate a “July effect.” Teaching hospitals had lower perioperative complication rates. Elderly hip fracture patients treated at teaching hospitals had 12% greater relative risk of mortality in July/August (ie, experience a “July effect”) compared with nonteaching hospitals during that time period (1998-2003). Although various methods exist for exploring the “July effect,” it is critical to take into account inherent month-to-month variation in outcomes and to use nonteaching hospitals as a control group.