Larson 2013.

Methods	CBA study
Participants	Index: 237 HIV+ tea pluckers with a CD4 count < 350 who began ART between 2004 and 2007 Control: Pool of workers from the 13,178 general work force population (Kenya)
Interventions	Intervention: Pharmacological, ART Control: Healthy, untreated general work force
Outcomes	Employment: Total days working per month Days spent plucking tea per month Total kg of tea harvested per month Total income per month
Notes	HIV
Risk of bias
Bias	Authors' judgement	Support for judgement
14. Blinding (Subjects)	Low risk	Participants were unaware of intervention.
15. Blinding (outcome assessors)	Low risk	Not reported. Objective outcomes that should have been unaffected by blinding.
16. Retrospective unplanned subgroup analysis	Unclear risk	Retrospective study, data dredging not clear.
17. Follow‐up	Low risk	Follow‐ups conducted for both index and reference at 6‐month intervals beginning 24 months pre‐ART until 24 months post‐ART.
18. Statistical tests	Low risk	Mean difference (95% confidence interval)
19. Compliance	Unclear risk	Compliance to ART was not monitored or insured. ART adherence is required for survival, therefore compliance is highly likely.
20. Outcome measures	Low risk	All predetermined outcome measures were analyzed and reported.
21. Selection Bias (population)	Low risk	Study used all HIV+ persons who visited the tea plantation hospitals and healthcare clinics. All participants were employees of two tea plantations in the Kericho District of Kenya. However, it is important to note that some participants in the reference group were likely HIV+ but were undiagnosed or had not declared their HIV status as positive. This could have impacted the results.
22. Selection bias (time)	Low risk	All participants were monitored between 2006‐2009.
23. Randomization	High risk	No randomization for index group. Index group was matched with four references who were randomized into subestate groups.
24. Allocation concealment	Unclear risk	Retrospective, non‐randomized study. Did not report the use of adequate sequence generation or allocation concealment techniques.
25. Adjustment for confounding	High risk	Adjustment for gender outcome differences. Age differences not addressed. SES differences not addressed. Disease severity not addressed. Migration differences not addressed.
26. Incomplete outcome data	High risk	6% attrition in index group addressed. No attrition data reported for controls. Data for workers in the general work force was incomplete due to a change in the management system resulting in the reassigning of employment identification numbers.
Baseline comparability	High risk	No baseline demographics were reported for the reference group. The index group mean age for women was 39.4 (27.4‐53) and for men was 39.5 (24.9‐54.4). The average years of experience for women was 8.2 (1‐24) years and for men was 7.7 (0.5‐23) years. Median baseline CD4 counts for women were 178 (91‐243) and for men were 153.3 (85‐215).