Back pain claim rates and the business cycle.

The causes of reported occupational back pain are controversial. Many observers appear to believe that job insecurity increases back pain compensation claims during recessions. The purpose of this study was to formally examine the impact of macro-economic forces-the business cycle-on the incidence of lost-time back pain claim rates in order to elicit clues to both its aetiology and reporting patterns. For Ontario between 1975 and 1993, age- and sex-adjusted lost-time back pain claim rates, stratified by industry sector (construction, manufacturing and trade), were regressed on the unemployment rate of the industry sector using time series methods. As a comparison group, the association between "acute" claim (fractures, lacerations, etc.) and the business cycle was also tested. Both back pain claim rates and acute claim rates increased during boom periods and decreased during recessionary periods. Time series analyses confirmed that these associations were statistically significant. The elasticities between claim rates and the unemployment rate were similar for back pain claims and acute claims. In addition, these associations were consistent in direction across all three industrial sectors tested. These results rebut the view that back pain claims increase during recessionary times.