[Prevalence of low back pain in the population]

Studies on selected populations lead to biased estimates of the prevalence of back pain and associated factors. In order to obtain a valid picture of the prevalence of back pain this review article focuses on epidemiological studies in the general population. These studies can be divided into general health surveys and surveys with specific reference to back pain. General health surveys including questions on the prevalence of back pain have the greatest methodological differences because of different aims. Due to these different aims, different target populations and different methods these studies depict point prevalences between 0.8% and 41% and 1-year prevalences between 15% and 56%. These general health surveys are contrasted with epidemiological studies especially designed to evaluate the prevalence of back pain. In these studies the point prevalence ranges between 14% and 42% and the lifetime period prevalence between 51% and 84%. Depending on the study reviewed the highest prevalence is found at age 50 to 64. This prevalence pattern may be explained by several effects that are discussed in this article. Severe forms of back pain increase even in the higher age groups, especially in women. Beside this effect the reviewed articles show either no difference between men and women or only a slightly higher prevalence in women. The problems faced by epidemiological studies on back pain, resulting from different definitions of "the back", severity, chronicity and different methodology, are discussed in detail.