Table 2.
Multivariate analysis with logistic regression, related to the distance-based approach. Odds ratios are expressed per 1 km distance of place of residence from the plant.
| Outcomes | OR | p | 95% CI | ORa | p | 95% CI |
|---|---|---|---|---|---|---|
| Cough (not due to a common cold) for some periods of the year | 0.74 | 0.070 | 0.53–1.02 | 0.79 | 0.215 | 0.54–1.14 |
| Cough ( not due to a common cold) for some periods of the year and for at least 2 years | 0.76 | 0.172 | 0.51–1.13 | 0.81 | 0.331 | 0.53–1.24 |
| Cough and sputum (not due to a common cold) for some periods of the year | 0.83 | 0.201 | 0.62–1.11 | 0.90 | 0.528 | 0.65–1.24 |
| Cough and sputum (not due to a common cold) for some periods of the year and for at least 2 years | 0.82 | 0.264 | 0.59–1.16 | 0.87 | 0.465 | 0.61–1.26 |
| High–grade dyspnoea (has to stop to take a breath at normal gait on the level) | 0.51 | 0.015 | 0.30–0.88 | 0.48 | 0.027 | 0.25–0.92 |
| Chronic bronchitis | 0.97 | 0.897 | 0.59–1.58 | 0.82 | 0.442 | 0.49–1.37 |
| Bronchial asthma or asthmatic bronchitis | 0.83 | 0.386 | 0.55–1.26 | 0.79 | 0.337 | 0.48–1.28 |
| Respiratory allergic symptoms associated with eye symptoms | 0.76 | 0.035 | 0.60–0.98 | 0.76 | 0.067 | 0.57–1.02 |
| Respiratory allergic symptoms | 0.81 | 0.126 | 0.63–1.06 | 0.79 | 0.143 | 0.57–1.08 |
Notes—OR: odds ratio; ORa: adjusted odds ratio; p: p-value; 95% CI: 95% confidence interval. “Chronic bronchitis”: when a participant stated that he/she had been diagnosed with chronic bronchitis. “Respiratory allergic symptoms” are a combination of (i) hay fever or some other condition that causes rhinorrhea or stuffy nose outside of common colds, (ii) attacks of breathing difficulty with wheezing (not due to a common cold), (iii) allergic reactions to powder, synthetic fibers, feathers and hairs. “Eye symptoms”: pruritus, redness and burning. Adjustments were performed for gender, age, BMI, smoking, cardiovascular comorbidity, occupational exposure, exposure to chemical–physical agents, and distance from the main road (buffer of 500 m). In the case of bronchial asthma and allergic symptoms, adjustment was performed for gender, age, BMI (for bronchial asthma only), smoking, occupational exposure, exposure to chemical-physical agents, and distance from the main road (buffer of 500 m).