Table 4

Newcastle-Ottawa Quality Assessment Scale—Observational Study Star Template

StudySelectionComparabilityOutcome/exposure
Appiah et al56***/*****/****/***
Huebner et al55***/*****/****/***
Liang et al54***/*****/****/***
Shrestha et al29***/*****/****/***
White et al53****/*****/****/***
  • Selection—maximum of 4 stars (representativeness of exposed cohort; selection of non-exposed cohort; and exposure).

  • Comparability—maximum of 2 stars (comparability between cohorts).

  • Outcome/ Exposure—maximum of 3 stars (adequacy of outcome, follow-up duration).

  • Adapted from Wells et al.47 Available at http://www.evidencebasedpublichealth.de.