Defining prevalence of low back pain is difficult, in part due to the variablility of back pain research. The differences in definitions and other methodology make regional and international comparisons nearly impossible.
The authors attempted to standardize the definitions of low back pain for epidemiological prevalence studies relying on input from an international panel of experts in back pain. 28 experts from 12 different countries participated in the process. The authors had hoped to develop at least two definitions of low back pain. A minimal definition to be used for large population-based general surveys, and an optimal definition for use in focused studies.
The authors reviewed 51 articles reporting population-based prevalence studies.They extracted 77 elements that could be included in a definition of low back pain prevalence. These elements were listed in a questionnaire and then ranked by the participants in round one.
Elements which were determined to reach a certain level of consensus were included in the elements for the questionnaire in round two. Also included in the round two questionnaire were new items suggested by the participants in round one.
Round three included items that reached a certain level of consensus from round two. Participants were asked to choose only one item in each element, for each of the two definitions.
A workshop orgainzed at the International Forum VIII for Primary Care Research on Low Back Pain in Amsterdam on June 8, 2006 was held to present the results of rounds one to three and discuss with the 24 participants.
Results of the workshop were included with those of rounds one throuh three in an online summary document. Participants were asked to vote for or against one minmal definition, and one optimal definition.
The final minimal definition of low back pain included two questions. The final optimal definition asked six questions and also included the numerical rating scale to measure severity.
The authors suggest that the results of this work should be considered as a step toward better standardization of definitions of low back pain for use in epidemiological studies. Their use is hoped to improve the synergy and usefulness for comparison between back pain studies internationally. Most likely researchers will want to also include their own preferred items. The hope is that they will use them in addition to the standard definitions developed and agreed upon.