Table 2.
Risk of bias of included studies
| Study | 1. Was the study’s target population a close representation of the national population in relation to relevant variables? | 2. Was the sampling frame a true or close representation of the target population? | 3. Was some form of random selection used to select the sample, OR was a census | 4. Was the likelihood of nonresponse bias minimal? | 5. Were data collected directly from the subjects (as opposed to a proxy)? | 6. Was an acceptable case definition used in the study? | 7. Was the study instrument that measured the parameter of interest shown to have validity and reliability? | 8. Was the same mode of data collection used for all | 9. Was the length of the shortest prevalence period for the parameter of interest appropriate? | 10. Were the numerator(s) and denominator(s) for the parameter of interest | 11. Summary item on the overall risk of study bias |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Braga et al. [38] (2005) | No | No | No | No | Yes | Yes | Yes | Yes | No | Yes | High |
| Ciapparelli et al. [39] (2007) | No | No | Yes | No | Yes | Yes | No | Yes | Yes | Yes | Moderate |
| DeTore et al. [45] (2021) | Yes | Yes | Yes | No | Yes | Yes | Yes | Yes | No | Yes | Low |
| Halász et al. [46] (2013) | No | No | No | No | Yes | No | Yes | Yes | Yes | No | High |
| Karatzias et al. [42] (2007) | No | No | Yes | No | No | Yes | Yes | No | Yes | Yes | High |
| Kiran and Chaudhury [47] (2016) | No | No | No | No | Yes | No | Yes | No | Yes | Yes | High |
| Neria et al. [48] (2002) | No | No | No | No | No | No | No | No | No | Yes | High |
| Newman et al. [49] (2010) | No | No | No | No | No | Yes | Yes | No | No | Yes | High |
| Pallanti et al. [50] (2004) | No | No | No | No | Yes | No | No | No | Yes | Yes | High |
| Peleikis et al. [51] (2013) | No | Yes | Yes | No | Yes | Yes | Yes | Yes | No | Yes | Moderate |
| Priebe et al. [16] (1998) | No | No | No | No | No | Yes | Yes | Yes | Yes | Yes | High |
| Resnick et al. [52] (2003) | No | No | No | No | Yes | Yes | Yes | No | Yes | Yes | High |
| Sarkar et al. [53] (2005) | No | No | No | No | Yes | Yes | Yes | Yes | No | Yes | High |
| Schäfer et al. [54] (2015) | No | No | Yes | No | Yes | Yes | Yes | Yes | Yes | Yes | Moderate |
| Seedat et al. [41] (2007) | No | No | No | No | Yes | Yes | Yes | No | Yes | Yes | High |
| Shaw et al. [17] (2002) | No | No | Yes | No | Yes | Yes | Yes | Yes | Yes | Yes | Moderate |
| Sim et al. [44] (2006) | No | No | Yes | No | Yes | Yes | Yes | No | Yes | Yes | Moderate |
| Sin et al. [57] (2010) | No | No | No | No | Yes | Yes | Yes | Yes | Yes | Yes | Moderate |
| Steel et al. [55] (2011) | No | No | Yes | No | Yes | Yes | Yes | Yes | Yes | Yes | Moderate |
| Strakowski et al. [40] (1993) | No | No | Yes | No | Yes | No | No | Yes | Yes | Yes | High |
| Tibbo et al. [43] (2003) | No | No | No | No | Yes | No | Yes | Yes | Yes | Yes | High |
| Vogel et al. [56] (2009) | No | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Low |