Proportion of individuals and incidence of claims per 10 person-years of eligibility stratified by body part between 2006 and 2010
| FL (n=1475) | MS (n=14 750) | p Value* | Rate ratio (95% CI; FL/MS) | Risk difference | |||||
|---|---|---|---|---|---|---|---|---|---|
| n (%) | Eligible months | Incidence (95% CI) | n (%) | Eligible months | Incidence (95% CI) | ||||
| Knee | 164 (11.1) | 55 630 | 0.35 (0.30 to 0.41) | 843 (5.7) | 600 760 | 0.17 (0.16 to 0.18) | <0.001 | 2.10 (1.78 to 2.48) | 0.18 |
| Neck | 346 (23.5) | 50 057 | 0.83 (0.74 to 0.92) | 1908 (12.9) | 570 015 | 0.40 (0.38 to 0.42) | <0.001 | 2.07 (1.84 to 2.32) | 0.43 |
| Low back | 545 (36.9) | 43 551 | 1.50 (1.38 to 1.63) | 3410 (23.1) | 525 390 | 0.78 (0.75 to 0.80) | <0.001 | 1.93 (1.76 to 2.11) | 0.72 |
| Distal arm | 135 (9.2) | 56 636 | 0.29 (0.24 to 0.33) | 906 (6.1) | 598 784 | 0.18 (0.17 to 0.19) | <0.001 | 1.58 (1.32 to 1.89) | 0.11 |
| Shoulder | 122 (8.3) | 57 004 | 0.26 (0.21 to 0.30) | 852 (5.8) | 600 593 | 0.17 (0.16 to 0.18) | <0.001 | 1.51 (1.25 to 1.82) | 0.09 |
| Other LE | 117 (7.9) | 56 978 | 0.25 (0.20 to 0.29) | 1064 (7.2) | 595 747 | 0.21 (0.20 to 0.23) | 0.311 | 1.15 (0.95 to 1.39) | 0.04 |
| Any claim | 755 (51.2) | 36 169 | 2.50 (2.33 to 2.68) | 5684 (38.5) | 450 805 | 1.51 (1.47 to 1.55) | <0.001 | 1.66 (1.53 to 1.79) | 0.99 |
Incidence=number of individuals with MSD claims per 10 person-years of eligibility during the period; rate ratio: incidence of FL/incidence of MS people; risk difference: the difference between the incidence of FL to the incidence of MS people.
*Computed z-ratio tests for two independent proportions.
FL, floor layers; LE, lower extremity; MS, MarketScan; MSD, musculoskeletal disorder.