Outcomes of Patients Receiving Maintenance Dialysis Admitted Over Weekends

Background Hospital admissions over weekends have been associated with worse outcomes in different patient populations. The cause of this difference in outcomes remains unclear; however, different staffing patterns over weekends have been speculated to contribute. We evaluated outcomes in patients on maintenance dialysis therapy admitted over weekends using a national database. Study Design Retrospective cohort study. Setting & Participants We included nonelective admissions of adult patients (≥18 years) on maintenance dialysis therapy (n = 3,278,572) identified using appropriate International Classification of Diseases, Ninth Revision, Clinical Modification ( ICD-9-CM ) codes for 2005-2009 using the Nationwide Inpatient Sample database. Predictor Weekend versus weekday admission. Outcomes The primary outcome measure was all-cause in-hospital mortality. Secondary outcomes included mortality by day 3 of admission, length of hospital stay, time to death, and discharge disposition. Measurements We adjusted for patient and hospital characteristics, payer, year, comorbid conditions, and primary discharge diagnosis common to maintenance dialysis patients. Results There were an estimated 704,491 admissions over weekends versus 2,574,081 over weekdays. Unadjusted all-cause in-hospital mortality was 40,666 (5.8%) for weekend admissions in comparison to 138,517 (5.4%) for weekday admissions ( P Limitations Use of ICD-9-CM codes to identify patients, defining weekend as midnight Friday to midnight Sunday. Conclusions Maintenance dialysis patients admitted over weekends have increased mortality rates and longer lengths of stay compared with those admitted over weekdays. Further studies are needed to identify the reasons for worse outcomes for weekend admissions in this patient population.