Low back pain: quantifying risk factors.
Garg-A; Hegmann-KT; Moore-JS
Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, U01-OH-008083, 2009 Dec; :1-182
A large scale, multi-site prospective cohort study of Low Back Pain (LBP) was incepted in 2003 with follow-up of the workers through 2006. The primary aims of the study were to quantify relationships between job physical factors and risk of LBP, as well as impairments of LBP. A total of 759 subjects were enrolled in the study, drawn from a total worker population of over 12,000 from 30 different industries in 4 diverse states (WI, UT, IL and TX). Complete baseline data were available on 647 subjects and complete follow-up data on 610 subjects with a total follow-up of 1033 person-days. All subjects were rendered a questionnaire, structured interview and physical examination at the baseline to document and quantify demographic data, social history, psychosocial factors, past medical history, and low back pain status and related history at the time of enrollment. A comprehensive job physical exposure assessment was made for each worker using worker interview, actual measurements of job physical exposure variables and videotaping of the job. The cohort was followed monthly to ascertain low back pain status. Workers were followed quarterly to ascertain a change in job physical exposure. The health outcome assessment team and job physical exposure assessment team were blinded to each other. One hundred forty eight participants (24.3%) never had a pain-free period that lasted 90 days or more. Out of 462 workers that were eligible, there were 182 incident cases of any LBP. The incidence rate for any LPB was 43.1 per 100 person-years. There was no evidence of association (p >/= 0.2) between incident cases of any LBP and age, gender, height. body weight. BMI, race, education level smoking (pack-years ). There was no evidence of association between incidence cases of any LBP and hobbies. There was evidence of association between incidence of any LBP and psychosocial scales: modified work APGAR (p = 0.0 I), modified Zung depression scale (p = 0.0 I) and tense/edge/nervous composite scale (p=0.02). There was evidence of association between any LBP and several different assessments of past history of LBP . Stratified analyses of job physical exposures showed evidence of association between job physical metries and any LBP. Lifting maximum weights near floor level (vertical height = 5") (p - 0.1 1 ) showed suggestive evidence of association and lifting at a greater than 52" (p < 0.0 1) showed evidence of association with incidence of any LBP. This study found no evidence of association between peak compressive force and incidence of any LBP and peak moment and incidence of any LBP . Composite Lifting Index (CLl) for those lifts and lowers that had origin, destination or both at or below 30" height showed that there was evidence of association between CLI and incident cases of any LBP (p = 0.05).
Back-injuries; Workers; Humans; Men; Women; Questionnaires; Physical-examination; Exposure-assessment; Statistical-analysis
Final Cooperative Agreement Report
National Institute for Occupational Safety and Health
University of Wisconsin Milwaukee