Introduction/Objective: To discuss the role of meta-analysis as part of an update of a 1988-1991 European Community-project aimed at assessing the effectiveness and cost-effectiveness of the use of lasers in medicine'.

Methods: Literature review, based on a Medline search strategy, reference tracking and reports of health technology assessment agencies. Both RCTs, non-randomized controlled trials and case-series were included, focusing on major laser applications in six specialties. Methodological quality assessment resulted in seven levels of evidence: four relating to effectiveness ('experimental', 'promising', 'established by clinical experience', 'established by several well-designed RCTs'), and three relating to cost-effectiveness ('no judgment possible', 'potentially cost-effective' and 'proven cost-effective').

Results: In total 58 major indications for the use of lasers were studied. Nine of these indications (15%) were judged 'established by several well-designed RCTs'. In only one of these indications the judgment could be based on the results of a published meta-analysis. In a minority of 24 indications (40%) there was sufficient evidence to reach a judgment on cost-effectiveness. For only one of these indications (4%), the use of lasers was judged 'proven cost-effective' There was no information available in the form of meta-analysis to support any judgment on cost-effectiveness.

Discussion: Effectiveness has been demonstrated for relatively few laser applications. The role of meta-analysis in this process has been limited, but could potentially be expanded. Evidence on cost-effectiveness of laser applications is often completely lacking. In cases where at least some evidence on costs has been collected, e.g. alongside a number of RCTs, meta-analysis could be a valuable tool, warranting further exploration. ' Banta HD, Schou I (Eds.) lasers in medicine. Effectiveness, cost-effectiveness and policy implications. Academic Publishing, Frederiksberg, Denmark, 1991.