Study designs of evaluations included in the review
Randomised controlled trials (RCTs) and quasi-experimental studies were included.
Specific interventions included in the review
Explicit feedback on smokers' biomarker status as an intervention or treatment component for smoking cessation. Biomarkers refer to biological indices of smoking-related harm, harm exposure, or genetic susceptibility to increased smoking-related disease risk. Common biomarkers in smoking studies include the following: carbon monoxide levels (expired or carboxyhaemoglobin); cotinine levels (serum, saliva or urinary); pulmonary functioning tests such as spirometry, plethysmography, and the single-breath nitrogen washout test; thiocyanate levels; chest X-rays; and genetic testing for lung cancer susceptibility (e.g. the presence of the CYP2D6 enzyme).
Participants included in the review
Individuals who smoke were included.
Outcomes assessed in the review
The outcomes that appear to have been included in the review were: attempts to quit smoking; an intention to quit smoking; smoking-related cognitions; emotions and behaviour change; long- and short-term smoking abstinence rates; biomarker levels; increased birth-weight as a result of maternal smoking cessation; and depression.
How were decisions on the relevance of primary studies made?
The author does not state how the papers were selected for the review, or how many of the reviewers performed the selection.