BackgroundThe global incidence of HIV infection is not significantly decreasing, especially in sub-Saharan African countries, including Ethiopia. Though there is availability and accessibility of free HIV services, people are not being diagnosed early for HIV, and hence patients are still dying of HIV-related causes. This research is aimed at verifying the effect of late diagnosis of HIV on HIV-related mortality in Central Zone Tigray, Ethiopia.MethodsA retrospective cohort study among adult (≥15 years old) HIV patients in three general hospitals of Tigray was conducted. Record reviews were carried out retrospectively from 2010 to 2015. Sample size was determined using stpower Cox in Stata software. Data were entered into EpiData version 3.1 software and transferred to Stata version 12 for analysis. Both bivariable and multivariable analyses were performed using Cox regression model to compare the HIV-related mortality of exposed (cluster of differentiation 4 cells count <350 cells/mm3) and nonexposed (≥350 cells/mm3) patients using adjusted hazard ratio (AHR) at 95% confidence interval (CI).ResultIn all, 638 HIV patients were analyzed, contributing 2,105.6 person-years. Forty-eight (7.5%) patients died of HIV-related causes with a mortality rate of 2.28 per 100 person-years. In the multivariable Cox regression model, patients with late diagnosis of HIV had a higher risk of mortality (AHR =3.22, 95% CI: 1.17–8.82) than patients with early diagnosis of HIV. Rural residence (AHR =1.96, 95% CI: 1.05–3.68), unemployment (AHR =2.70, 95% CI: 1.03–7.08), bedridden patients (AHR =2.98, 95% CI: 1.45–6.13), ambulatory patients (AHR =2.54, 95% CI: 1.05–6.15), and baseline hemoglobin level of <11 mg/dL (AHR =3.06, 95% CI: 1.51–6.23) were other independent predictors of mortality.Conclusion and recommendationsLate diagnosis of HIV increased HIV-related mortality. Rural residence, unemployment, bedridden and ambulatory patients, and baseline hemoglobin level <11 mg/dL were also independent predictors of HIV-related mortality.