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Table 3 Rate of loss of Function Univariate Coefficients (ml per year) (after allowance for regression to the mean)

From: The Darlington and Northallerton Long Term Asthma Study: pulmonary function

   Actual FEV1 Best FEV1 Best FVC
   Estimate 95% CI Estimate 95% CI Estimate 95% CI
Gender (male v female) 7.7 0.8+,16.1 6.2 2.5+,14.9 12.2 2.5,21.9
Age at entry (per decade) (difference from age 50) Linear 5.6+ 11.4+,0.2 10.1 + 15.9 +,4.8 + 2.1+ 8.7+,4.5
  quadratic 4.3 + 6.0 +,2.5 + 5.0 + 6.8 +,3.3 + 4.5 + 6.5 +,2.6 +
  cubic 1.3 0.3,2.3 2.0 1.0,2.9 1.4 0.3,2.6
Duration of asthma at entry (per decade) (difference from duration 20 yrs) Linear 3.1+ 7.4+,1.1 0.5 3.8+,4.8 0.1 4.8+,5.0
  quadratic 3.6 0.6,6.6 2.7 0.5+,5.8 5.6 2.2,9.0
  cubic 0.9 + 1.6 +,0.1 + 0.9 + 1.7 +,0.1 + 1.4 + 2.3 +,0.6 +
Atopic 5.7+ 14.2+,2.8 0.2 8.5+,8.9 3.0+ 12.7+,6.7
Childhood asthma (versus no childhood asthma) Gap 3.4+ 16.7+,9.9 1.4 12.2+,15.0 4.0+ 19.4+,11.3
  Yes 20.8 + 30.6 +,10.9 + 10.6 + 20.9 +,0.4 + 22.0 + 33.3 +,10.6 +
Social Class (versus classes 1 and 2) Three 6.3+ 16.5+,3.8 11.2 + 21.7 +,0.8 + 9.2+ 20.8+,2.3
  Four and Five 10.2+ 21.0+,0.7 14.5 + 25.6 +,8.3 + 8.6+ 21.0+,3.9
Amount smoked (per 10 pack years) 1.5 0.6+,3.7 0.2 2.1+,2.4 2.9 0.4,5.4
Best PEF(per 10% deficit) 3.3 + 5.3 +,1.2 + 2.8 + 4.8 +,0.7 + 0.4+ 2.7+,2.0
Actual/Best PEF(10% deficit) 12.7 + 15.6 +,9.8 + 2.8+ 6.2+,0.6 0.6+ 4.1+,2.8
  1. (+) Indicates relative gain in function