Table 4

Summary of quality assessments—descriptive studies*

StudyClear objectiveStudy pop’n clearParticipation
Participants: same time period and pop’n. Criteria: prespecified and uniformSample size: justification, power. Effect: estimate and varianceExposure: measure prior to outcome measureSufficient time: exposure to outcomeLevel of exposure measuredExposure: clear, valid, reliable and consistentExposure: assessment more than onceOutcome: clear, valid, reliable and consistentOutcome: blinded assessmentLoss to follow-up ≤20%Confounders: measured and adjusted forQuality rating—quantitative outcomes†
Cauley et al, 201539 YY?NNNYN?NANNYNPOOR
Chlebowski et al, 201040 YYY?NYYNYNAYN?NFAIR
Heiney et al, 201042 YYY?NYYNAYNAYNNNFAIR
Kumar et al, 201243 YY??N?YNANNANNYNPOOR
Kusek et al, 200244 YY??NYYNYNAYN?NFAIR
  • *Quality assessment checklists adapted from Study Quality Assessment Tools: National Heart, Lung, and Blood Institute (available from:

  • †Quality rated as good, fair or poor with respect to the quantitative recruitment-related outcomes of interest in this systematic review.

  • ?, not reported/unable to determine; N, no; NA, not applicable; Y, yes.