Influence of physical, psychological and behavioural factors on consultations for back pain.

Over 34,000 questionnaires were used to study occurrence and consultations for back pain in the community. The 12-month period prevalence was 24% and 13% of the sample consulted a doctor. Elderly women were at greatest risk of back pain. The consultation rate increased in both sexes throughout middle age, but declined in men over the age of 55 yr. Back pain was associated with the Goldberg General Health Health Questionnaire score suggesting psychiatric morbidity [odds ratio (OR) = 2.05; confidence interval (CI) 1.89-2.23], obesity (OR = 1.59; CI 1.40-1.79), and cigarette smoking (OR = 1.52; CI 1.36-1.70). Vigorous daily activity was positively associated with back pain in men aged 18-39 yr (OR = 1.37; CI 1.02-1.85), and women aged 18-39 yr (OR = 1.50; CI 1.08-2.09), but was negatively associated with back pain in women aged over 65 yr (OR = 0.35; CI 0.16-0.76). Alcohol consumption was also negatively associated with back pain (OR = 0.72; CI 0.62-0.85). The prevalence of arthritis, constipation and respiratory disorders was increased in those who consulted for back pain corrected for the other variables. Thus back pain was substantially more common in women compared to men over 55 yr. Psychiatric morbidity, cigarette smoking and obesity were associated with back pain at all ages, but the effect of physical exercise appeared to change with age. Further studies are required to explain the sex differences and nature of the associations.