Wynn-Jones et al1 performed a meta-analysis of studies that followed patients with back pain and assessed if they were absent from work and, if so, for how long. They found that back pain occurs in about 15% of all patients and that 68% of these returned to work within 1 month. After half a year almost all, 93%, were back at work. The variation in results between studies was very large with the percentage off work ranging from 2% to 56% and the percentages returning to work ranging from 55% to 99%.

Back pain as such is not immediately a problem but it is long-lasting and disabling pain that mostly affects patients and society. Therefore, these figures are important to enable us to understand what effects primary prevention of back pain would have on long-term disability as a result of back pain. It is generally assumed that the incidence of back pain is about 10% per year. If we then take the figures from above into account, one would have to address 10 000 healthy workers with an intervention that reduces back pain with 20% to prevent sick leave longer than 6 months in two workers. Therefore, it seems that for efficiency reasons return to work interventions would be preferable unless primary prevention …