Table 4

Explanatory factors for selected respiratory symptoms reported over an 18 year period among employees exposed to TDI and referents (multivariate logistic regression model, generalised estimating equation approach)

Respiratory symptom and covariate4-150 Risk ratio 95% CI
Wheezing in chest (n=138):
 Cigarettes (packs/day)3.42.0 to 5.7
 History of non-occupational asthma3.41.5 to 8.0
 Asthma induced by di-isocyanate8.84.0 to 19.4
 Exposed to TDIv referents0.80.4 to 1.5
Cough lasting 2 months (n=37):
 Cigarettes (packs/day)2.21.3 to 3.7
 History of non-occupational asthma0.70.1 to 3.3
 Asthma induced by di-isocyanate0.80.1 to 5.5
 Exposed to TDIv referents0.90.4 to 2.2
Chest pain on exercise (n=63):
 Cigarettes (packs/day)1.00.5 to 2.0
 History of non-occupational asthma2.90.5 to 14.9
 Asthma induced by di-isocyanate4.21.6 to 10.7
 Exposed to TDIv referents0.70.3 to 1.9
Shortness of breath (n=59):
 Cigarettes (packs/day)1.40.8 to 2.3
 History of non-occupational asthma1.60.5 to 5.6
 Asthma induced by di-isocyanate1.70.6 to 4.8
 Exposed to TDIv referents1.10.5 to 2.4
One or more symptoms (n=232):
 Cigarettes (packs/day)2.41.6 to 3.6
 History of non-occupational asthma3.01.3 to 6.7
 Asthma induced by di-isocyanate4.22.1 to 8.4
 Exposed to TDI vreferents0.80.4 to 1.3
  • 4-150 Based on 2677 periodic examinations, sex included as covariate (data not shown).