Table 7

GRADE evidence profile for cohort studies: Electronic nicotine delivery systems (ENDS) and no ENDS for reducing cigarette smoking

Quality assessmentSummary of findingsCertainty in estimates
Study event ratesRelative risk (95% CI)Anticipated absolute effects over 6–12 monthsOR
Quality of evidence
No of participants (studies)
Range follow-up time
Risk of biasInconsistencyIndirectnessImprecisionPublication biasENNDS*ENDSENNDS*ENDS
Cessation/nicotine abstinence (Includes self-reported and biochemically validated by eCO)
 7826 (8)
6–36 mo
Serious limitations†No serious limitationsNo serious limitationsSerious imprecision‡Undetected1300/5693336/21330.74 (0.55 to 1.00)213 per 100056 fewer per 1000 (96 fewer to 0 more)⊕OOO
  • *The estimated risk control was taken from the median estimated control risks of the cohort studies.

  • †All studies were rated as high risk of bias for adjustment for prognosis variable; assessment of prognostic factors; assessment of outcomes; adequate follow-up of cohort; and similarity of cointerventions between groups.

  • ‡95% CI for absolute effects include clinically important benefit and no benefit.