Operational definitions.

<div><p>Background</p><p>Weekend effect’ is a term used to describe the increased mortality associated with weekend emergency admissions to hospitals compared with admissions on weekdays. This effect was not investigated in Ethiopia among adult patients admitted to hospitals. We aimed to find out whether the weekend effect exists in the country’s a teaching hospital.</p><p>Methods</p><p>The study was conducted among adult medical patients admitted at Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia, from September 2020 to September 2023. We extracted the data from the electronic medical records, and those with missed outcomes, length of hospital stays, and diagnosis were excluded. We used a multivariable logistic regression model to determine the association between the outcome and risk factors. The Cox proportional hazard model was utilized to establish the correlation between admission times and mortality risk incidence. Statistical significance was determined using a P value of less than 0.05. The Kaplan-Meier curve was utilized to estimate the risk of in-hospital mortality over the duration of the hospital stay.</p><p>Results</p><p>A of 5564 patients were admitted to medical wards (n = 5001) and intensive care unit (ICU) (n = 563) during the study periods. In binary multivariable analysis, weekend medical wards and ICU admitted adult medical patients had a 38% (AOR, 1.38, 95% CI, 1.17, 1.65) and 50% (AOR, 1.50, 95% CI, 1.02, 2.20) higher in-hospital mortality compared weekdays admitted patients, respectively. The cumulative mortality risk incidence was higher among medical ward-admitted patients (AHR, 1.26, 95% CI, 0.09, 1.46, P value = 0.051) and significantly higher among ICU-admitted adult patients (AHR, 1.28, 95% CI, 1.21, 1.75, P value = 0.01) during the weekends. There was no statistically significant mortality difference among night versus day or office hours versus off-office hours admitted patients. Moreover, we did identify significant differences in the duration of hospital stays between weekends and weekdays.</p><p>Conclusions</p><p>In this study, weekend-admitted adult medical patients in wards or ICUs have higher in-hospital mortality rates. This underscores a need for comprehensive nationwide data to improve weekend admitted patients’ quality of care and treatment outcomes.</p></div>