Table 2.
Proportion of individuals and incidence of claims per 10 person-years of eligibility stratified by body part between 2006-2010
| Floor layers (n=1,475) | MarketScan (n=14,750) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| n (%) | Eligible Months | Incidence (95% CI) | n (%) | Eligible Months | Incidence (95% CI) | p-value* | Rate Ratio (95% CI) (FL/MS) | Risk Difference | |
| Knee | 164 (11.1) | 55630 | 0.35 (0.30, 0.41) | 843 (5.7) | 600760 | 0.17 (0.16, 0.18) | <0.001 | 2.10 (1.78, 2.48) | 0.18 |
| Neck | 346 (23.5) | 50057 | 0.83 (0.74, 0.92) | 1908 (12.9) | 570015 | 0.40 (0.38, 0.42) | <0.001 | 2.07 (1.84, 2.32) | 0.43 |
| Low Back | 545 (36.9) | 43551 | 1.50 (1.38, 1.63) | 3410 (23.1) | 525390 | 0.78 (0.75, 0.80) | <0.001 | 1.93 (1.76, 2.11) | 0.72 |
| Distal Arm | 135 (9.2) | 56636 | 0.29 (0.24, 0.33) | 906 (6.1) | 598784 | 0.18 (0.17, 0.19) | <0.001 | 1.58 (1.32, 1.89) | 0.11 |
| Shoulder | 122 (8.3) | 57004 | 0.26 (0.21, 0.30) | 852 (5.8) | 600593 | 0.17 (0.16, 0.18) | <0.001 | 1.51 (1.25, 1.82) | 0.09 |
| Other LE | 117 (7.9) | 56978 | 0.25 (0.20, 0.29) | 1064 (7.2) | 595747 | 0.21 (0.20, 0.23) | 0.311 | 1.15 (0.95, 1.39) | 0.04 |
| Any Claim | 755 (51.2) | 36169 | 2.50 (2.33, 2.68) | 5684 (38.5) | 450805 | 1.51 (1.47, 1.55) | <0.001 | 1.66 (1.53, 1.79) | 0.99 |
Note: incidence = number of individuals with MSD claims per 10 person-years of eligibility during the period; Rate ratio: incidence of floor layers/incidence of MarketScan people. Risk Difference: the difference between the incidence of floor layers to the incidence of MarketScan people.
*
computed z-ratio tests for two independent proportions