The prevalence of low back pain in adults: a methodological review of the literature.

The prevalence of low back pain (LBP) has been reported in the literature for different populations. Methodological differences among studies and lack of methodological rigor have made it difficult to draw conclusions from these studies. A systematic review was done for adult community prevalence studies of LBP published from 1981 to 1998. The technique of capture-recapture was performed to estimate the completeness of the search strategy used. Established guidelines and a methodological scoring system were used to critically appraise the studies. Thirteen studies were deemed methodologically acceptable. Differences in the duration of LBP used in the studies appeared to affect the prevalence rates reported and explain much of the variation seen. It was estimated that the point prevalence rate in North America is 5.6%. Further studies using superior methods are needed, however, before this estimate can be used with confidence to make health care policies and decisions relating to physical therapy.

Critical appraisal of the health research literature: prevalence or incidence of a health problem.

This article identifies and discusses criteria that can be used by health professionals to critically appraise research articles that estimate the prevalence or incidence of a disease or health problem. These guidelines will help determine the validity and usefulness of such community assessment studies. The criteria relate to the validity of the study methods (design, sampling frame, sample size, outcome measures, measurement and response rate), interpretation of the results and applicability of the findings. The research question "What is the prevalence of dementia in Canada?" is used as an example for this paper.