The epidemiological profile of a middle-aged population with low back pain in southern Brazil.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To assess the prevalence and the general characteristics of low back pain (LBP) in a middle-aged population living in southern Brazil. SUMMARY OF BACKGROUND DATA: LBP is a widespread musculoskeletal condition. It is the main cause of disability in developed countries. It is necessary and relevant to study the risk factors for LBP to plan preventative action. A cross-sectional study of a middle-aged population in the South of Brazil was designed to look at the prevalence and general characteristics of LBP. METHODS: A cross-sectional study was developed in a city located in southern Brazil. Data were collected from 1005 individuals at randomized public locations. A protocol was designed to evaluate the general characteristics of the population: age, sex, level of education, socioeconomic status, body mass index, occupation, smoking, physical activity, anxiety, and depression. After the initial evaluation, the individuals were asked if they had had low back pain at least once in their lifetime. Those who answered "Yes" continued the questionnaire that evaluated pain intensity, characteristics, and related disability. After the entire group was analyzed (N = 1005), a separate study was performed on the participants younger than 40 years (N = 701). RESULTS: The mean age was 33.74 years (±14.76) and 61.6% of the participants were females. Seventy-two percent of the participants had had LBP at least once in their lives. The mean of visual analogue scale intensity of pain was 4.51 (±2.27). The prevalence of female sex (P = 0.006) and anxiety (P < 0.001) was higher in those with LBP. In the group younger than 40 years, the prevalence of LBP was 69.7% and anxiety (P < 0.001) was the only factor related to LBP. CONCLUSION: Low back pain is a highly prevalent condition in a middle-aged population living in southern Brazil. Higher levels of anxiety and female sex were related to this condition in all groups, but when it was analyzed in the participants younger than 40 years, anxiety was the only significant variable related with LBP. LEVEL OF EVIDENCE: 3.