In Reply.—Although any study has its limitations, we believe that the results of our randomized controlled trial are valid and contribute to the existing evidence on the (lack of) efficacy of lumbar supports in the prevention of back pain in industry.1
One potential limitation of our study is the relatively low compliance rate. It is possible that, on account of possible selection of noncompliant subjects, an existing effect of the lumbar supports was missed that would have been found had the compliance rate been higher. Higher compliance rates could, for example, be obtained, by making the use of the supports mandatory. However, not every employer will choose or be able to do this. The results reported in our article are results that can be expected if an employer decides to introduce lumbar supports for workers involved in manual material handling, without making the use mandatory (and thus accepting partial noncompliance). It is important, however, to realize that the analysis of the results in the subgroup of workers with a high compliance rate did not show any indication of beneficial effects of lumbar supports.
van Poppel MNM, Koes BW, Bouter LM. Preventing Low Back Pain in Industry—Reply. JAMA. 1998;280(23):1993-1994. doi:10-1001/pubs.JAMA-ISSN-0098-7484-280-23-jbk1216