For the five dengue reviews, the efficacy of interventions was calculated as the ratio of entomological indices in the intervention and control groups. There was considerable overlap in the included studies between the five dengue reviews. The most comprehensive review was by Erlanger et al. [41] including 56 publications covering 61 interventions. The authors identified 19 studies on chemical control of vectors. Pooled effects were only calculated for five studies that used outdoor adulticiding and reported their results as Breteau Index (BI) (number of containers with Aedes spp. larvae per 100 houses). Ten studies assessed biological control, of which 9 were included in a pooled analysis. The one study not included showed increased dengue risk in the intervention arm. GRADE suggested low to very low quality evidence for both chemical and biological interventions, and scores were low partly because study validity was not reported and heterogeneity was not explored or explained in the reviews (such reporting may have raised the score, or may not if the validity of included studies was low).