18-yr cumulative incidence of respiratory/allergic symptoms/diseases and risk factors in the Pisa epidemiological study

Background: Few population-based studies on the effects of environmental exposure variation exist. Aim: Assessing respiratory symptom/disease incidence related to risk factor exposure changes. Methods: A longitudinal general population sample from two surveys (PISA2:1991–1993; PISA3:2009–2011; no. = 970), aged ≥20 years at baseline, completed a questionnaire on respiratory symptoms/diseases, risk factor exposure and performed spirometry. 18-year follow-up cumulative incidence of respiratory symptoms/diseases and longitudinal changes (persistence, incidence, remittance) in risk factor exposure were computed. Results: Cumulative incidence values were: 3.2% (corresponding to a 1.8‰/year incidence rate), asthma; 6.6% (3.8‰/year), asthma attacks; 4.5% (2.6‰/year), wheeze; 31.7% (21.0‰/year), allergic rhinitis-AR; 7.6% (4.4‰/year), chronic obstructive pulmonary disease-COPD; 16.1% (9.7‰/year), usual cough; 18.5% (11.3‰/year), usual phlegm; 30.7% (20.1‰/year), dyspnoea 1+; 13.9% (8.3‰/year), airway obstruction. The following associations emerged among respiratory symptom/disease cumulative incidence and risk factor exposure changes: a two-to-five fold higher risk for COPD, phlegm, cough, dyspnoea, asthma attacks, airway obstruction in persistent smokers; a two-to-three fold higher risk for COPD in remittent smokers; a two-fold higher risk for AR, phlegm and a four-fold higher risk for asthma in subjects with persistent occupational exposure; a two-fold higher risk for cough, phlegm, dyspnoea, AR in subjects with incident occupational exposure; a two-fold higher risk for AR, asthma attacks, COPD in subjects with incident traffic exposure. Conclusions: Our study showed noteworthy respiratory symptom/disease incidence values and indicated that life-style and environmental exposure changes can differently influence onset. This information could be useful for primary prevention strategies in order to reduce the chronic disease burden in the general population.