Table 4

Included studies risk of bias

AuthorItem 1Item 2Item 3Item 4Item 5Item 6Item 7Item 8Item 9Item 10Overall risk of bias
External validityInternal validity
Ayeni et al 40 HRHRHRLRLRHRHRLRLRLRMR
Dickenson et al 67 HRHRHRLRLRHRLRLRLRHRMR
Domb et al 55 HRHRHRLRLRLRHRHRLRHRHR
Farrell et al 59 HRHRHRLRLRHRHRLRLRLRMR
Georgiadis et al 60 HRHRHRLRLRHRHRHRLRLRHR
Jayakar et al 61 HRHRHRLRLRLRHRLRLRHRMR
Ji et al 56 HRHRHRLRLRLRLRHRLRLRMR
Kassarjian et al 41 HRHRHRLRLRLRHRLRLRHRMR
Kolo et al 51 HRHRHRLRLRLRHRLRLRHRMR
Lahner et al 42 HRHRHRLRLRHRHRLRLRLRMR
Lahner et al 57 HRHRHRLRLRHRHRLRLRHRHR
Lee et al 64 HRHRHRLRLRLRLRLRLRLRLR
Leunig et al 52 HRHRLRLRLRLRLRLRLRLRLR
Mayes et al 58 HRHRHRLRLRLRLRLRLRLRLR
Mayes et al 43 HRHRHRLRLRLRLRLRLRLRLR
Mayes et al 65 HRHRHRLRLRLRLRLRLRLRLR
Mineta et al 62 HRHRHRLRLRLRLRLRLRHRMR
Narvani et al 44 HRHRHRLRLRHRHRLRLRLRMR
Neiman et al 63 HRHRHRLRLRHRHRLRLRLRMR
Neumann et al 45 HRHRHRLRLRLRHRLRLRLRMR
Panzer et al 46 HRHRHRLRLRLRLRHRLRLRMR
Philippon et al 53 HRHRHRLRLRHRHRLRLRLRMR
Pizzolatti et al 47 HRHRHRLRLRLRHRHRLRLRMR
Register et al 49 HRHRHRLRLRHRHRLRLRLRMR
Schmitz et al 50 HRHRHRLRLRLRLRLRLRHRMR
Silvis et al 48 HRHRHRHRLRHRHRLRLRLRHR
Teichtahl et al 68 HRHRHRLRLRLRLRLRHRLRMR
Tresch et al 66 HRHRHRLRLRLRHRHRLRLRMR
Yuan et al 54 HRHRHRHRLRHRHRHRLRHRHR
  • Risk of bias items.

  • 1. Was the study‚Äôs target population a close representation of the national population in relation to relevant variables, for example, age, sex, occupation?

  • 2. Was the sample 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 taken?

  • 4. Was the likelihood of non-response 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 (eg, prevalence of low back pain) shown to have reliability and validity (if necessary)?

  • 8. Was the same mode of data collection used for all subjects?

  • 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 appropriate?

  • HR, high risk of bias; LR, low risk of bias; MR, moderate risk of bias.