Derivation and validation of clinical subphenotypes of adult sepsis in Africa: A latent class analysis of infection site and organ dysfunction

Objective Sepsis is a heterogeneous syndrome characterized by substantial variation in infection source, organ dysfunction, and clinical outcomes, and a disproportionate burden in Africa. We aimed to derive and externally validate clinical subphenotypes among adults hospitalized with sepsis in Africa. Design We used latent class analysis with infection source and organ dysfunction as model inputs. We labeled classes post hoc according to their predominant clinical features. We evaluated associations between subphenotypes and 30-day mortality using multivariable logistic regression. Setting Hospitals in Uganda, Rwanda, Liberia, Tanzania, and Malawi. Patients We pooled data from three prospective cohorts of adults hospitalized with sepsis in Uganda, Rwanda, and Liberia for model derivation and independent cohorts from Tanzania and Malawi for external validation. Interventions None. Measurements and Main Results The derivation dataset included 467 adults with sepsis, of whom 128 (27.4%) died within 30 days of admission. Latent class analysis identified four subphenotypes: Class 1 (heterogeneous; n=227; 30.8% mortality), Class 2 (abdominal; n=141; 31.9%), Class 3 (pulmonary; n=68; 16.2%), and Class 4 (soft tissue; n=31; 6.5%). Mortality differed significantly across the four classes (p=0.003). Compared with Class 1, Classes 3 (aOR 0.22, 95% CI 0.10-0.47) and 4 (aOR 0.14, 95% CI 0.02-0.52) had lower odds of 30-day mortality. External validation in 316 adults demonstrated high classification certainty (entropy=0.78; mean maximum posterior probabilities, 0.89-0.92), with similar mortality patterns across corresponding subphenotypes. Conclusions Latent class analysis identified reproducible clinical sepsis subphenotypes defined by infection source and organ dysfunction with distinct mortality risks. These externally validated subphenotypes may improve risk stratification and inform subphenotype-based clinical trials and treatment strategies in Africa.