Background Sub-Saharan Africa has the highest rates of child mortality worldwide. Little is known about post-hospital outcomes after an index hospitalization for older children. We determined 12-month post-hospital mortality rate and identified factors associated with higher mortality. Methods In this prospective cohort study, we enrolled children 2–12 years of age admitted to the pediatric wards of two public hospitals in northwestern Tanzania. Participants or proxies were contacted at 3, 6 and 12 months post-hospitalization. The primary outcome measured was mortality. Factors associated with mortality were determined using Cox regression analysis. Results A total of 506 participants were enrolled. In-hospital mortality rate was 7.7% (39/506). Of the 467 participants discharged, the post-hospital mortality rate was 10.1% (47/467). Sickle cell disease (Hazard Ratio (HR) 3.32, 95% CI 1.44–7.68), severe malnutrition (HR 3.19, 95% CI 1.18–8.57), neurologic diseases (HR 3.51, 95% CI 1.35–9.11), heart disease (HR 7.11, 95% CI, 2.89–17.51), cancer (HR 11.79, 95% CI 4.95–28.03), and septic shock (HR 4.64, 95% CI 1.42–15.08) had higher association with mortality compared to other diagnoses. The risk factors significantly associated with mortality included older age (HR 1.01, 95% CI 1.00–1.08), lower hemoglobin level (HR 0.83, 95% CI 0.76–0.90), lower Glasgow Coma Scale (HR 0.66, 95% CI 0.59–0.74), history of decreased urine output (HR 2.87, 95% CI 1.49–5.53), higher respiratory rate (HR 1.02, 95% CI 1.00–1.03), estimated glomerular filtration rate less than 60 ml/min/1.73m2 (binary) (HR 1.84, 95% CI 1.10–3.10), and lower oxygen saturation (HR 0.96, 95% CI 0.92–0.99). Conclusions Post-hospital mortality is disturbingly high among children 2–12 years of age in Tanzania. Post-hospital interventions are urgently needed especially for older children with chronic illnesses.
