Table 6.
Presentation of the risk of bias of included studies
| S/N | Author (s) and year of publication | Was the study’s target population a close representation of the national population in relation to relevant variables, e.g. age, sex, occupation? | Was the sampling frame a true or close representation of the target population? | Was some form of random selection used to select the sample, OR, was a census undertaken? | Was the likelihood of non-response bias minimal? | Were data collected directly from the subjects (as opposed to a proxy)? | Was an acceptable case definition used in the study? | Was the study instrument that measured the parameter of interest (e.g. prevalence of low back pain) shown to have reliability and validity (if necessary)? | Was the same mode of data collection used for all subjects? | Were the numerator(s) and denominator r(s) for the parameter of interest appropriate | Summary on the overall risk of study bias |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Adébayo et al., 2015 [44] | No (high risk) | No (high risk) | No (high risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Moderate risk (4–6) |
| 2 | Amusa et al., 2016 [33] | Yes (low risk) | No (high risk) | No (high risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Moderate risk (4–6) |
| 3 | Ayodele et al., 2012 [32] | Yes (low risk) | Yes (low risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 4 | Berhane et al., 2012 [34] | Yes (low risk) | Yes (low risk) | No (high risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 5 | Fourie et al., 2010 [35] | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 6 | Guehi et al., 2016 [30] | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 7 | Guira et al., 2016 [31] | No (high risk) | No (high risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 8 | Hirigo et al., 2016 [36] | No (high risk) | No (high risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 9 | Mashinya et al., 2015 [37] | No (high risk) | Yes (low risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 10 | Mbunkah et al., 2014 [38] | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 11 | Muhammad et al., 2013 [45] | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 12 | Muyanja et al., 2016 [39] | No (high risk) | No (high risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 13 | Ngatchou et al., 2013 [40] | Yes (low risk) | Yes (low risk) | No (high risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 14 | Obirikorang et al. 2016 [41] | Yes (low risk) | Yes (low risk) | No (high risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 15 | Sawadogo et al., 2005 [43] | Yes (Low risk) | Yes (low risk) | Yes (low risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 16 | Sobieszczyk et al., 2016 [29] | Yes (low risk) | Yes (low risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 17 | Tesfaye et al., 2014 [42] | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | No (high risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |
| 18 | Zannou et al., 2009 [28] | No (high risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Yes (low risk) | Low risk (0–3) |