Evidence for necrotising otitis externa (NOE) diagnosis and management is limited, and outcome reporting is heterogeneous. International best practice guidelines were used to develop consensus diagnostic criteria and a core outcome set (COS).

The study was pre-registered on the Core Outcome Measures in Effectiveness Trials (COMET) database. Systematic literature review identified candidate items. Patient-centred items were identified via a qualitative study. Items and their definitions were refined by multidisciplinary stakeholders in a two-round Delphi exercise and subsequent consensus meeting.

The final COS incorporates 36 items within 12 themes: Signs and symptoms; Pain; Advanced Disease Indicators; Complications; Survival; Antibiotic regimes and side effects; Patient comorbidities; Non-antibiotic treatments; Patient compliance; Duration and cessation of treatment; Relapse and readmission; Multidisciplinary team management.

Consensus diagnostic criteria include 12 items within 6 themes: Signs and symptoms (oedema, otorrhoea, granulation); Pain (otalgia, nocturnal otalgia); Investigations (microbiology [does not have to be positive], histology [malignancy excluded], positive CT and MRI); Persistent symptoms despite local and/or systemic treatment for at least two weeks; At least one risk factor for impaired immune response; Indicators of advanced disease (not obligatory but mut be reported when present at diagnosis). Stakeholders were unanimous that there is no role for secondary, graded, or optional diagnostic items. The consensus meeting identified themes for future research.

The adoption of consensus-defined diagnostic criteria and COS facilitates standardised research reporting and robust data synthesis. Inclusion of patient and professional perspectives ensures best practice stakeholder engagement.

Adolescents living with HIV (ALHIV) experience a high burden of mental health disorder which is a barrier to antiretroviral therapy adherence. In Zimbabwe, trained, mentored peer supporters living with HIV (Community Adolescent Treatment Supporters – CATS) have been found to improve adherence, viral suppression and psychosocial well-being among ALHIV. The Friendship Bench is the largest integrated mental health programme in Africa. We hypothesise that combining the CATS programme and Friendship Bench will improve mental health and virological suppression among ALHIV compared with the CATS programme alone.

We will conduct a cluster-randomised controlled trial in 60 clinics randomised 1:1 in five provinces. ALHIV attending the control arm clinics will receive standard CATS support and clinic support following the Ministry of Health guidelines. Those attending the intervention arm clinics will receive Friendship Bench problem-solving therapy, delivered by trained CATS. Participants with the signs of psychological distress will be referred to the clinic for further assessment and management. The primary outcome is HIV virological failure (≥1000 copies/ml) or death at 48 weeks. Secondary outcomes include the proportion of adolescents with common mental disorder symptoms (defined as Shona Symptom Questionnaire (SSQ-14) score ≥8), proportion with depression symptoms (defined as Patient Health Questionnaire (PHQ-9) score ≥11), symptom severity (mean SSQ-14 and PHQ-9 scores) and EQ-5D score for health-related quality of life.

This trial evaluates the effectiveness of peer-delivery of mental health care on mental health and HIV viral load among ALHIV. If effective this intervention has the potential to be scaled-up to improve these outcomes.

Trial registration: PACTR201810756862405. 08 October 2018.