Prevalence of complementary and alternative medicine (CAM) use by the general population: a systematic review and update

There was evidence of substantial CAM use in the 15 countries surveyed. Where national trends were discernable because of consistent measurement, there was no evidence to suggest a change in 12-month prevalence of CAM use since the previous systematic reviews were published in 2000. Periodic surveys are important to monitor population-level CAM use. Use of government-sponsored health surveys may enhance robustness of population-based prevalence estimates. Comparisons across countries could be improved by standardising approaches to data collection.