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. Author manuscript; available in PMC: 2014 Dec 1.
Published in final edited form as: Ann Rheum Dis. 2013 Apr 9;72(12):10.1136/annrheumdis-2012-202949. doi: 10.1136/annrheumdis-2012-202949

Table 3.

OR and the 95% CIs (95% CI) for tender and swollen joint positivity (≥1 affected joint) in relation to PM2.5 and PM10

Tender joint positive
visits n = 101
OR* (95% CI)		 Swollen joint positive
visits n = 165
OR* (95% CI)
PM2.5† 1.07 (0.71 to 1.63) 1.12 (0.80 to 1.58)
n FDRs = 861
n visits = 1509
PM10†‡ 0.95 (0.70 to 1.28) 1.02 (0.79 to 1.32)
  n FDRs = 739
  n visits = 1288
*

Adjusted for age, ethnicity, gender, current smoking status, education and recruitment site.

†

Continuous variables, the OR represents a change in risk for a 1 SD increase in PM2.5 and PM10. The SDs for PM2.5 and PM10 were 2.8 µg/m3 and 5.1 µg/m3, respectively.

‡

The reduced sample size for PM10 is due to a smaller number of air-monitoring stations measuring PM10. The number of visits positive for the outcome is 97 for tender joint and 152 for swollen joint.

PM2.5, particulate matter ≤2.5 µm in diameter; PM10, particulate matter ≤10 µm in diameter.