“…After screening 2294 titles, 243 abstracts, and 81 full texts, 26 articles met criteria for inclusion ( Figure 2 ), comprising 3 RCTs described in 6 articles 32 , 33 , 34 , 35 , 36 , 37 and 20 observational studies (16 longitudinal designs 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 and 4 cross-sectional quasi–waiting list control designs comparing current vs future recipients of an intervention 54 , 55 , 56 , 57 ) ( Figure 3 ; eTable 1 in the Supplement ). Most studies selected participants based on medical or social vulnerability.…”