1st place, PREMUS best paper competition: workplace and individual factors in wrist tendinosis among blue-collar workers - the San Francisco study

摘要

Objective Workplace studies have linked hand/wrist tendinosis to forceful and repetitive hand exertions, but the associations are not consistent. We report findings from a prospective study of right wrist tendinosis among blue-collar workers. Methods Workers (N=413) at four industries were followed for 28 months with questionnaires and physical examinations every 4 months to identify incident cases of right wrist tendinosis. Exposure assessment offeree and repetition were based on field measurements and video analysis to determine repetition rate and the percent time (% time) in heavy pinch (>1 kg-force) or power grip (>4 kg-force). All exposure variables were measured at the level of the individual and task. For workers responsible for >1 task, a time-weighted average exposure was calculated based on task hours per week. A proportional hazards model was used to assess the relationship between exposures and incidence of wrist tendinosis. Results During the 481 person-years of follow-up, there were 26 incident cases of right wrist tendinosis [incidence rate (IR) 5.40 cases per 100 person-years]. Adjusting for age, gender, and repetition, wrist tendinosis was associated with % time spent in heavy pinch [hazard ratio (HR) 5.01, 95% CI 1.27-19.79]. Composite exposure measure American Conference of Industrial Hygienists Threshold Limit Value (ACGIH-TLV) for hand activity level (HR 3.95, 95% CI 1.52-10.26) was also associated with the outcome for the medium-exposure group using video-based total repetition rate. Conclusions The workplace factors predicting wrist tendinosis were time-weighted average values of % time spent in heavy pinch and the ACGIH-TLV for Hand Activity Level. The % time spent in power grip was not a significant predictor, nor were any measures of repetition. An exposure-response relationship was observed for the % time spent in heavy pinch. These findings may improve programs for preventing occupational wrist tendinosis.