Table 5.
Two-way interaction terms for associations between physical work-related stressors and arthritis
| Heavy physical work | Kneeling or squatting | Heavy lifting | Arm elevation | Awkward trunk posture | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| OR (95%CI) | p | OR (95%CI) | p | OR (95%CI) | p | OR (95%CI) | p | OR (95%CI) | p | |
| Doctor-diagnosed arthritis | ||||||||||
| Age (years)a | 0.96 (0.90–1.03) | 0.27 | 1.06 (0.97–1.51) | 0.20 | 0.93 (0.86–1.00) | 0.04 | 1.02 (0.87–1.19) | 0.81 | 0.99 (0.92–1.07) | 0.85 |
| Body mass indexa | 0.88 (0.81–0.96) | 0.006 | 1.01 (0.91–1.13) | 0.80 | 0.96 (0.87–1.06) | 0.46 | 1.43 (1.12–1.82) | 0.004 | 0.76 (0.69–0.84) | ≤0.001 |
| Household incomea | 1.13 (1.06–1.20) | ≤0.001 | 1.12 (1.04–1.20) | 0.003 | 1.10 (1.03–1.18) | 0.005 | 0.99 (0.85–0.15) | 0.90 | 1.08 (1.01–1.15) | 0.03 |
| Educationa | 1.03 (0.97–1.11) | 0.32 | 1.00 (0.92–1.08) | 0.97 | 1.09 (1.01–1.17) | 0.02 | 0.80 (0.66–0.96) | 0.02 | 1.03 (0.96–1.10) | 0.42 |
| Never married | 1.23 (0.76–1.99) | 0.40 | 1.51 (0.89–2.57) | 0.13 | 0.84 (0.43–1.67) | 0.62 | 0.52 (0.13–2.04) | 0.35 | 0.60 (0.25–1.44) | 0.25 |
| Married/cohabiting | 1.22 (1.02–1.47) | 0.03 | 1.17 (0.94–1.46) | 0.16 | 1.12 (0.90–1.39) | 0.32 | 0.95 (0.59–0.53) | 0.83 | 1.40 (1.15–1.71) | 0.001 |
| Separated/widowb | 1.00 | – | 1.00 | – | 1.00 | – | 1.00 | – | 1.00 | – |
| Symptom-defined arthritis | ||||||||||
| Age (years) a | 0.94 (0.82–1.07) | 0.35 | 1.47 (1.26–1.71) | ≤0.001 | 1.02 (0.89–1.16) | 0.80 | 1.83 (1.27–2.63) | 0.001 | 1.12 (0.97–1.28) | 0.11 |
| Body mass indexa | 0.58 (0.49–0.68) | ≤0.001 | 0.97 (0.81–1.15) | 0.70 | 0.83 (0.71–0.98) | 0.03 | 1.53 (1.03–2.30) | 0.04 | 0.69 (0.59–0.81) | ≤0.001 |
| Household incomea | 1.10 (1.00–1.22) | 0.06 | 1.10 (0.99–1.23) | 0.08 | 1.03 (0.92–1.15) | 0.53 | 1.05 (0.83–1.32) | 0.70 | 1.11 (1.00–1.23) | 0.048 |
| Educationa | 1.55 (1.39–1.73) | ≤0.001 | 1.45 (1.28–1.65) | ≤0.001 | 1.49 (1.33–1.68) | ≤0.001 | 1.45 (1.03–2.03) | 0.03 | 1.44 (1.29–1.61) | ≤0.001 |
| Never married | 0.89 (0.37–2.19) | 0.81 | 1.53 (0.53–4.48) | 0.43 | 0.29 (0.06–1.31) | 0.11 | c | c | 0.19 (0.02–1.47) | 0.11 |
| Married/cohabiting | 1.16 (0.87–1.55) | 0.32 | 2.92 (2.10–4.04) | ≤0.001 | 0.87 (0.63–1.21) | 0.42 | 3.12 (1.53–6.33) | 0.002 | 1.12 (0.84–1.50) | 0.44 |
| Separated/widowb | 1.00 | – | 1.00 | – | 1.00 | – | 1.00 | – | 1.00 | – |
aVariables treated as ordinal in models; breference group; cempty cells due to small counts; significant interaction terms are bolded