The Role of Perceived Job Exertion and Age as Moderators of the Relationship Between Gender and Upper Extremity Musculoskeletal Disability and Pain in Injured Workers

Purpose This cross-sectional study aimed to determine if age and perceived job exertion (PJE) moderate the effect of gender on upper extremity (UE) disorders in injured workers. Methods We sampled a consecutive cohort of patients attending a specialty clinic for injured workers with UE musculoskeletal problems. We measured UE disability and pain using the Quick Disability of the Arm, Shoulder, and Hand (QDASH). Participants reported their PJE on a Global Rating of Change scale ranging from 1 (minimal perceived exertion) to 15 (maximal perceived exertion). Linear regression was used to explore the effect of gender on QDASH. We probed the moderating role of age and PJE using floodlight regression and identified the Johnson-Neyman (JN) region of age and PJE, where the effect of gender on QDASH becomes significant at the 95% level. Results We analyzed 418 participants, of whom 44% were women. The effect of gender on QDASH was significant for women aged 49 or younger (JN-region border: Age = 48.5, effect = 4.4, SE = 2.2, p = 0.05). Women workers with UE disorders younger than 49 years old report higher levels of pain and disability than do men. After the age of 49 years, both men and women workers experience a similar worsening of UE pain and disability with increasing age. Pain and disability increase with increased perceived job demands similarly for both men and women workers. Conclusions Women younger than 49 years had higher levels of UE pain and disorders than men. Both men and women workers reported higher UE disability with an increase in their PJE.