Abstract

OBJECTIVES: To describe workers with low back symptoms, to identify risk factors and to assess the occupational consequences separately in men and women. METHODS: A descriptive study was conducted between 1 October 1996 and 31 December 1996 in a sample of workers selected at random from all types of small companies in the Paris area. A group of 202 occupational physicians interviewed 7129 workers with a standardised questionnaire including the Nordic questionnaire. Data analysis was performed by sex in the two groups: with low back pain and without low back pain over the previous 12 months. The group with low back pain was then divided into four subgroups: mild cases (without referred pain), moderate cases (with referred pain above the knee), serious cases (with referred pain below the knee), and low back pain with occupational consequences. RESULTS: 7010 questionnaires were able to be evaluated. The sample consisted of 54.8% of men (3842) and 45.2% of women (3168), with a mean age of 37.8 and 37.0 years, respectively (p < 0.05). The following risk factors occurred significantly more often in men: high weight, height, body mass index (BMI), smoking, number of children, increased driving time and work time, material handling tasks, uncomfortable working positions. Most women were clerks (53%). Non-conditional logistic regression applied to the whole sample identified female sex as a risk factor (odds ratio (OR) = 1.85, 95% confidence interval (95% CI) 1.58 to 2.13). The following risk factors were common to both sexes: lifting weights > 10 kg, in women (OR 1.69, 95% CI 1.27 to 2.25) and in men (OR 1.27, 95% CI 1.06 to 1.53), uncomfortable working positions (OR 2.04, 95% CI 1.58 to 2.17 and OR 1.85, 95% CI 1.69 to 2.43), and absence of means to achieve good quality work (OR 1.39, 95% CI 1.19 to 1.63 and OR 1.38, 95% CI 1.15 to 1.65), respectively. Driving was a risk factor only in men and its importance increased with driving time (driving > 4 hours a day (OR 1.61, 95% CI 1.24 to 2.09)). Severe low back pain was linked to female sex (10.2% of women v 6.6% of men), high BMI, aging, and uncomfortable working positions. Low back pain with occupational consequences (n = 258) was not linked to sex, but only to aging and severity. CONCLUSIONS: The incidence and severity of low back pain were higher in women, although they seemed to be less exposed to known occupational risk factors. However, our results indicate a preponderance of these risk factors among female workers. Particular attention must therefore be paid to lifting of weights and uncomfortable working positions in female jobs (clerk, trading, health care staff).