Table 2

Evidence Project risk of bias assessment7 for studies included in the effectiveness review

StudyStudy design includes pre/post intervention dataStudy design includes control or comparison groupStudy design includes cohortComparison groups equivalent at baseline on sociodemographicsComparison groups equivalent at baseline on outcome measuresParticipants randomly selected for assessmentParticipants randomly allocated to the interventionControl for potential confoundersFollow-up rate>=75%
2006–2008 The Border Contraceptive Access Study10 12 13NoYesYesNoYesNoNoYesYes
2000 Mexican National Health Survey analysis14NoYesNoNoN/AYes*NoYesN/A
1979 Mexico National Fertility and Mortality Study9NoYesNoNR†N/AYesNoNoN/A
1974 Colombian Fertility and Contraceptive Use Survey11NoYesNoNR†N/AYes‡NoNoN/A
  • *Four-stage probability proportionate to size sampling.

  • †Authors state that the comparison groups were similar, but no comparative data provided to assess this.

  • ‡Three-stage probability sampling.

  • N/A, not applicable; NR, not reported.