Study designs of evaluations included in the review
No inclusion criteria for the study design were pre-specified. The included studies were randomised controlled trials, (RCTs), quasi-experimental studies, pre-test post-test studies and time series.
Specific interventions included in the review
To be eligible, the studies needed to be of guided imagery excluding receptive imagery. Studies where the effect of imagery could not be isolated from other interventions were excluded, as were studies using imagery for primary psychiatric diagnosis. Studies using self-hypnosis were included if imagery was the primary component and any induction was described as a simple relaxation technique. The studies mainly used instruction accompanied by audiotape for practice at home, and focused on physiological imagery, pleasant imagery, or structured reframing of an experience. The studies were either single session or lasted between 2 and 18 weeks.
Participants included in the review
To be eligible, the studies needed to be of adult participants. The included studies assessed healthy medical students, people suffering chronic illness, or those experiencing acute illness or invasive procedures.
Outcomes assessed in the review
No specific outcomes were pre-specified. The included studies assessed physiological measures (immune parameters) and psychosocial measures such as anxiety, focus of control and coping, as well as quality of life.
How were decisions on the relevance of primary studies made?
The author did not state how the papers were selected for the review, or how many reviewers performed the selection.