Crude and adjusted IRRs of CTS diagnoses and surgery by wrist exposure intensity and duration variables and by sex
| Wrist exposures | Sex | ||||
|---|---|---|---|---|---|
| Intensity | Duration | ||||
| Median velocity of flexion/extension of the wrist (per 1 °/s)* | Mean power frequency (per 0.01 Hz)* | Non-neutral wrist postures (per %time)* | Working proportion during the previous year (per unit)†‡ | Women vs men† | |
| Total (n=4198) | |||||
| CTS diagnoses | |||||
| IRRCrude (95% CI) | 1.41 (1.12 to 1.79) | 0.85 (0.65 to 1.10) | 0.99 (0.89 to 1.11) | 0.77 (0.47 to 1.26) | 2.84 (1.94 to 4.16) |
| IRRAdj (95% CI) | 1.37 (1.10 to 1.71) | 1.53 (1.21 to 1.92) | 0.93 (0.82 to 1.05) | 0.92 (0.54 to 1.56) | 4.11 (2.61 to 6.48) |
| CTS surgery | |||||
| IRRCrude (95% CI) | 1.52 (1.15 to 2.01) | 0.81 (0.59 to 1.11) | 1.00 (0.87 to 1.15) | 0.76 (0.37 to 1.23) | 3.31 (2.07 to 5.30) |
| IRRAdj (95% CI) | 1.44 (1.11 to 1.88) | 1.55 (1.18 to 2.05) | 0.92 (0.78 to 1.07) | 0.75 (0.50 to 1.80) | 6.37 (3.64 to 11.3) |
| Men (n=2596) | |||||
| CTS diagnoses | |||||
| IRRCrude (95% CI) | 1.12 (0.74 to 1.71) | 1.55 (0.54 to 4.44) | 1.00 (0.85 to 1.17) | 0.65 (0.32 to 1.28) | |
| IRRAdj (95% CI) | 1.15 (0.75 to 1.77) | 1.49 (0.51 to 4.35) | 1.01 (0.86 to 1.19) | 0.75 (0.35 to 1.60) | |
| CTS surgery | |||||
| IRRCrude (95% CI) | 1.19 (0.70 to 2.02) | 2.22 (0.59 to 8.30) | 0.95 (0.77 to 1.17) | 0.54 (0.23 to 1.26) | |
| IRRAdj (95% CI) | 1.22 (0.70 to 2.10) | 2.04 (0.54 to 7.74) | 0.97 (0.78 to 1.21) | 0.82 (0.32 to 2.08) | |
| Women (n=1602) | |||||
| CTS diagnoses | |||||
| IRRCrude (95% CI) | 1.46 (1.15 to 1.86) | 1.54 (1.21 to 1.95) | 0.84 (0.70 to 1.01) | 0.87 (0.41 to 1.85) | |
| IRRAdj (95% CI) | 1.45 (1.13 to 1.84) | 1.52 (1.20 to 1.92) | 0.82 (0.68 to 0.98) | 1.00 (0.47 to 2.15) | |
| CTS surgery | |||||
| IRRCrude (95% CI) | 1.53 (1.15 to 2.02) | 1.53 (1.14 to 2.05) | 0.89 (0.71 to 1.11) | 0.79 (0.32 to 1.97) | |
| IRRAdj (95% CI) | 1.51 (1.13 to 2.01) | 1.56 (1.17 to 2.08) | 0.85 (0.68 to 1.07) | 1.00 (0.40 to 2.52) | |
Continuous linear effects determined by log-linear Poisson regression. Total and by sex.
Bold indicates statistically significant IRRs (p<0.05).
*Adjusted for effects of working proportion during the previous year, sex, age, body mass index, fractures near the wrist and comorbidity.
†Estimates from the model with median velocity for flexion/extension of the wrist.
‡Estimates were similar when working proportion during the previous year was replaced with the working proportion during the previous 2 years or the previous 5 years.
Adj, adjusted; CTS, carpal tunnel syndrome; IRR, incidence rate ratio.