Table 3

The risk of treatment for pain in the distal upper extremities with increasing levels of wrist angular velocity and exertion of force

Physical exposuresEventsPerson-yearsIRIRR, crude
(95% CI)
IRR, model 1*
(95% CI)
IRR, model 2
(95% CI)
Wrist angular velocity
Continuous variable
 Men698454 800.215.31.02 (1.01 to 1.03)1.02 (1.00 to 1.03)1.02 (1.00 to 1.03)
 Women387161 959.624.00.99 (0.97 to 1.00)0.98 (0.97 to 0.99)0.97 (0.96 to 0.99)
Categorical variable
Low (ref)
 Men (3.5–<10.4 o/s)212199 898.510.6111
 Women (3.5–<10.4 o/s)6718 757.335.7111
Medium
 Men (10.4–14.3 o/s)390187 154.120.81.96 (1.66 to 2.32)2.08 (1.73 to 2.50)1.20 (0.94 to 1.54)
 Women (10.4–18.3 o/s)8944 539.420.00.56 (0.41 to 0.77)0.82 (0.59 to 1.14)0.82 (0.59 to 1.14)
High
 Men (>14.3 o/s)9667 747.814.21.34 (1.05 to 1.70)1.48 (1.15 to 1.92)1.13 (0.86 to 1.49)
 Women (>18.3 o/s)23197 704.023.60.66 (0.50 to 0.87)0.70 (0.53 to 0.93)0.71 (0.53 to 0.93)
Wrist force
Continuous variable
 Men698454 800.215.31.48 (1.37 to 1.61)1.50 (1.38 to 1.63)1.50 (1.38 to 1.63)
 Women387161 959.624.00.97 (0.84 to 1.13)0.87 (0.74 to 1.02)1.13 (0.89 to 1.43)
Categorical variable
Low (ref)
 Men (1.0–2.45)765190 180.18.7111
 Women (1.0–2.15)14759 919.124.5111
Medium
 Men (>2.45–4.15)313162 266.119.32.22 (1.84 to 2.68)2.23 (1.83 to 2.72)1.99 (1.55 to 2.56)
 Women (>2.15–2.55)23197 704.023.60.96 (0.78 to 1.19)0.79 (0.63 to 0.99)0.71 (0.53 to 0.94)
High
 Men (>4.15)220102 354.021.52.48 (2.02 to 3.03)2.65 (2.13 to 3.29)2.31 (1.72 to 3.09)
 Women (>2.55)93377.626.61.09 (0.55 to 2.13)1.07 (0.54 to 2.10)1.06 (0.54 to 2.08)
  • Estimates in bold significant at p<0.05. Model 1: adjusted for age and calendar-year, diagnoses of rheumatoid arthritis and fractures of the wrist, elbow or arm. Model 2: adjusted for model 1 and the other exposure, that is, force or repetition.

  • *No cases of incident treatment among women with rheumatoid arthritis. This variable was left out in the analyses for women.

  • †Tertiles of exposure were defined for sexes separately.

  • IR, incidence rate per 10 000 person-years; IRR, incidence rate ratio.