Hip Fracture and the Weekend Effect: Does Weekend Admission Affect Patient Outcomes?
Reduced hospital staffing on weekends is a hypothesized risk factor for adverse health outcomes—commonly referred to as the weekend effect.
We conducted a study on the effect of weekend admission on short-term outcomes among US hip fracture patients. We selected Nationwide Inpatient Sample (1998–2010) patients with a principal diagnosis of femoral neck fracture and grouped them by day of admission (weekend or weekday). We used multivariate logistic and linear regression analyses, controlling for age, race, sex, number of comorbidities, and other risk factors, to calculate odds ratios (ORs) of mortality and perioperative complications as well as mean difference in length of hospital stay.
Our study population included 96,892 weekend and 248,097 weekday admissions. Compared with patients admitted on weekdays, patients admitted on weekends had lower mortality (OR, 0.94; 95% confidence interval [CI], 0.89-0.99) and shorter mean hospital stay (estimate, 3.74%; 95% CI, 3.40-4.08) but did not differ in risk of perioperative complications (OR, 1.00; 95% CI, 0.98-1.02).
Weekend admission did not predict death, perioperative complications, longer hospital stay, or other adverse short-term outcomes. Our study data do not support a weekend effect among hip fracture admissions in the United States.
Our results are largely consistent with the literature on the topic.11-14 An Australian study of 4183 patients with acute hip fracture found no significant difference in 2- or 30-day mortality among weekend and weekday admissions.11 Similarly, 2 Danish studies did not find a difference in hospital-stay or 30-day mortality between weekend and weekday admissions among samples of 600 and 38,020 patients with hip fracture, respectively.12,13 In US patients, a cross-specialty study that included hip fractures did not find a difference in hospital-stay mortality among 22,001 admissions in the state of California in 1998.14 Our analysis significantly extended the findings of these studies by using comprehensive admission data from 46 US states over a 13-year period (1998–2010) and by examining outcomes other than mortality, including perioperative complications and length of hospital stay.
Our study had several limitations. First, the clinical data on fracture diagnoses and surgical procedures were based on ICD-9-CM codes, limiting our ability to account for the full details of fracture severity and subsequent management. Second, our analyses were limited to outcomes during the hospital stay, and we could not examine the effect of weekend admission on readmission and long-term mortality. Third, because of the dichotomization of admission day in the NIS database, we could not selectively examine the effect of Friday, Saturday, or Sunday admission on our outcomes. Fourth, we excluded admissions that were missing demographic and clinical data, potentially creating a complete-case bias. However, these exclusions were needed to accurately capture the common presentation of acute hip fracture, and there is no reason to believe that differences in record coding were nonrandom. Last, our study was observational, and we cannot rule out the effect of residual confounding on our results.
Our results failed to show a weekend effect on mortality, perioperative complications, or length of hospital stay in US patients with hip fracture. The reason for this, as suggested before,12 may be that hip fractures are becoming easier to diagnose. Furthermore, the observation that hospital stay was shorter for weekend admissions suggests that, despite decreased staffing of nursing and rehabilitation services, the lower volume of elective surgeries on weekends may actually increase staff availability to hip fracture patients.
