Introduction:
Children discharged from hospital following management of complicated severe acute malnutrition (SAM) have a high risk of mortality, readmission and failed nutritional recovery. Current management approaches fail to sufficiently promote convalescence after inpatient nutritional rehabilitation. Novel interventions during the post-discharge period could enhance convalescence to help children survive and thrive.

Methods and analysis:
The Co-SAM trial is an adaptive, multicountry, phase III, individually randomised clinical trial, based on the principles that (i) interacting biological and social factors drive multimorbidity in children with SAM, and (ii) both medical and psychosocial interventions may therefore ameliorate underlying causal pathways to reduce morbidity and mortality and improve recovery. Children aged 6–59 months with complicated SAM, who have stabilised and started the transition to ready-to-use therapeutic food (RUTF), will be enrolled and randomised to one of five trial arms (standard-of-care alone; antimicrobials; reformulated RUTF; psychosocial support; or a combination of all strategies). Standard-of-care, which is provided in all trial arms, includes RUTF until nutritional recovery (defined as weight-for-height Z-score >−2, mid-upper arm circumference >12.5 cm and oedema-free since the last study visit), and other management recommended in WHO guidelines. The 12-week antimicrobial package provides daily co-formulated rifampicin and isoniazid (with pyridoxine) and 3 days of azithromycin monthly. The reformulated RUTF, which incorporates medium-chain triglycerides and hydrolysed protein to increase nutrient bioavailability and reduce metabolic stress, is provided at the same dose and duration as standard RUTF. The 12-week psychosocial package includes caregiver problem-solving therapy, educational modules, peer support groups and child play. The combined arm includes all interventions. Children start their intervention package prior to hospital discharge, with follow-up data collection in study clinics at 2, 4, 6, 8, 12 and 24 weeks. The primary composite outcome is death, hospitalisation or failed nutritional recovery within 24 weeks post-randomisation. An interim analysis will allow unpromising arms to be dropped, while the final analysis will be conducted when 1266 children have completed the study. Embedded process evaluation and laboratory substudies will explore the mechanisms of action of the interventions.