Table 4.
Adjusted odds ratios and 95% confidence intervals for associations between ln Pb in quartiles and knee outcomes (joint-based analysis)a
| Knee rOA | Knee sxOA | |||||
|---|---|---|---|---|---|---|
| Knee outcomesb | ln Pb quartilesc | aORd | 95% CI | ln Pb quartilesc | aORd | 95% CI |
| Q2 | 1.09 | 0.81 to 1.48 | Q2 | 1.10 | 0.77 to 1.56 | |
| Presence | Q3 | 1.18 | 0.89 to 1.58 | Q3 | 1.16 | 0.83 to 1.62 |
| Q4 | 1.27 | 0.93 to 1.74 | Q4 | 1.24 | 0.86 to 1.79 | |
| Q2 | 1.07 | 0.80 to 1.43 | Q2 | 1.06 | 0.75 to 1.51 | |
| Severitye | Q3 | 1.25 | 0.95 to 1.65 | Q3 | 1.16 | 0.83 to 1.62 |
| Q4 | 1.34 | 0.99 to 1.81 | Q4 | 1.23 | 0.85 to 1.77 | |
aaOR, adjusted odds ratio; CI, confidence interval; ln Pb, natural log-transformed lead; rOA, radiographic osteoarthritis; sxOA, symptomatic osteoarthritis; Q, quartile; breference category is no rOA for rOA outcomes, no sxOA for sxOA presence and rOA with no symptoms for sxOA severity outcomes; cmean Pb (±SD) in micrograms per deciliter level by quartile: Q1 (reference), 0.94 (±0.20); Q2, 1.5 (±0.15); Q3, 2.13 (±0.24); Q4, 4.92 (±3.93); dadjusted for age, sex, race and ethnicity, BMI, current smoking and current drinking; eproportional odds assumption met; a common OR describes the relationship between mild, moderate or severe compared to none, or between moderate or severe compared to mild or none.