Table 4.
Assessment of risk for included studies, following AHRQ guidelines.
| Reference | Aam et al. (7) | Altieri et al. (10) | Arauz et al. (29) | Banerjee et al. (5) | Barba et al. (11) | Benedictus et al. (12) | Biffi et al. (13) | Corraini et al. (6) | Koning et al. (14) | Douiri et al. (15) | Espinosa del Pozo et al. (34) | Garcia et al. (38) | Gong et al. (16) | Griauzde et al. (18) | Greenberg et al. (39) | Ihle-Hansen et al. (19) | Koivunen et al. (21) | Li et al. (40) | Madureira et al. (22) | Miller et al. (35) | Moulin et al. (23) | Nakano et al. (30) | Nakase et al. (24) | Nys et al. (31) | Planton et al. (25) | Qureshi et al. (32) | Sakai et al. (36) | Su et al. (33) | Tang et al. (26) | Tveiten et al. (27) | Xiong et al. (28) | You et al. (37) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Overall risk* | L | L–M | L–M | L–M | L–M | L–M | L | L | M | L–M | M | L–M | L | L | M | L–M | L–M | M | M | U | L | M | L–M | L–M | M | L–M | M | L–M | L | L | L | L |
| Selection bias* | ||||||||||||||||||||||||||||||||
| Was the allocation sequence random? | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | U |
| Was the allocation of treatment adequately concealed? | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | Y |
| Were participants analyzed within their original groups? | – | Y | – | – | Y | Y | Y | – | Y | – | – | – | Y | Y | Y | – | Y | – | Y | – | Y | – | Y | – | Y | – | – | – | – | Y | Y | Y |
| Did the study apply inclusion/exclusion criteria uniformly? | Y | Y | – | – | Y | Y | Y | – | Y | Y | Y | Y | Y | Y | Y | Y | Y | – | Y | – | Y | – | Y | – | N | – | N | – | – | Y | Y | – |
| Were cases and controls selected appropriately? | – | – | Y | Y | – | – | Y | – | – | – | – | – | – | – | – | – | Y | – | – | – | Y | – | Y | – | Y | – | Y | – | – | – | – | |
| Did the recruitment strategy differ across study groups? | N | N | – | – | N | N | N | Y | N | N | – | – | N | N | N | N | N | – | N | – | N | – | N | – | U | – | – | – | N | N | N | – |
| Does the study account for confounding and modifying variables? | Y | U/N | N | Y | Y | Y | Y | Y | S | Y | S | Y | Y | Y | Y | S | Y | Y | Y | – | Y | S | U | Y | S | Y | N | Y | Y | Y | Y | Y |
| Performance bias | ||||||||||||||||||||||||||||||||
| Did the study rule out any impact from a concurrent intervention? | N | Y | Y | Y | Y | Y | Y | Y | Y | Y | N | Y | Y | Y | Y | Y | – | Y | Y | – | Y | Y | Y | Y | Y | Y | Y | – | Y | – | Y | Y |
| Did the study maintain fidelity to protocol? | – | Y | – | Y | Y | Y | Y | Y | Y | Y | – | Y | Y | Y | Y | Y | Y | Y | Y | – | Y | Y | Y | Y | Y | Y | – | Y | Y | Y | Y | Y |
| Attrition bias | ||||||||||||||||||||||||||||||||
| If attrition was a concern, were missing data addressed? | Y | Y | – | Y | Y | N | Y | Y | N | Y | N | N | Y | Y | Y | Y | N | Y | N | – | Y | N | Y | Y | N | Y | N | N | N | Y | S | Y |
| Detection bias | ||||||||||||||||||||||||||||||||
| Were follow up times the same between groups? | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | – | – | Y | Y | Y | Y | U | Y | Y | – | Y | N | Y | Y | Y | Y | – | Y | Y | U | Y | Y |
| Were the outcome assessors blinded appropriately? | – | N | – | N | U | Y | U | U | Y | U | – | Y | Y | Y | Y | U | U | U | Y | N | Y | N | U | Y | U | U | – | Y | Y | U | Y | Y |
| Were exposures assessed using valid and reliable measures? | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | U | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| Were outcomes assessed using valid and reliable measures? | Y | Y | Y | U | Y | Y | Y | Y | U | Y | Y | Y | Y | Y | U | Y | Y | Y | Y | U | Y | Y | Y | U | Y | Y | Y | Y | Y | Y | Y | Y |
| Were confounding variables assessed using valid and reliable measures? | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | N | Y | Y | Y | Y | U | Y | N | Y | Y | Y | Y | Y | Y | Y | Y | Y | – |
| Reporting bias | ||||||||||||||||||||||||||||||||
| Were the outcomes prespecified and all outcomes reported? | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/N | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/N | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y | Y/Y |
*
L, Low, M. Medium; H, High; U, Unclear; S, Some; Y, Yes; N, No.