Group 2 studies
We found no study conducted in adult populations reporting the proportion of hospital admissions prolonged by ADRs. Two paediatric studies, one from Nigeria36 and one from South Africa53 reported this proportion (Table 4). In the Nigerian study36 0.29% children experienced ADR-related prolongation of their hospital admission. ADR preventability, presentations, implicated drugs, and HIV exposure were not reported. In the South African study53 0.99% admissions were prolonged by ADRs. Most prolongations were for antibiotic-associated diarrhoea, although a variety of other admission-prolonging ADRs occurred, including ADRs attributed to corticosteroids and immunosuppressants. Only one study reported the proportion of admissions prolonged by preventable ADRs, being 2/1106 (0.19%)53. Only one study, conducted in South Africa, reported HIV prevalence among children whose hospital stays were prolonged by ADRs, being 18%.53