Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk
Allocation concealment (selection bias)	Low risk	Comment: unit of allocation as by villages
Similar baseline characteristics	High risk	Quote: “Findings indicate that while largely similar, despite village‐ as well as sample‐level matching on educational attainment, young people in intervention areas were marginally better off in terms of household economic status, educational attainments, and economic activity than those in control areas.” Comment: baseline characteristics were not adequately similar
Similar baseline outcome measurement	Unclear risk	Quote: “The training programme was not evaluated and hence no baseline data were available for assessing longer‐term changes among trainees” Comment: insufficient information to permit judgement
Blinding of participants and personnel (performance bias)	Unclear risk
Blinding of outcome assessment (detection bias)	Unclear risk
Incomplete outcome data (attrition bias)	Unclear risk	Comment: insufficient information to permit judgement
Prevention of knowledge of allocated intervention	Unclear risk	Comment: insufficient information to permit judgement
Protection against contamination	Low risk	Comment: allocation was by village
Selective reporting (reporting bias)	Unclear risk	Comment: insufficient information to permit judgement, and no protocol was found.
Other bias	Low risk	Comment: study appears free of other bias