TEMPORAL CHANGES IN RESPIRATORY SYMPTOMS/DISEASES AND ASSOCIATED RISK FACTORS IN REAL LIFE

Background: The prevalence of respiratory diseases increased during last centuries and the rapid rise in the prevalence of such diseases cannot be explained by genetic factors. Analyses on general population samples investigated at interval of some years can permit to better comprehend these increases and the associated risk factors, adding new evidences on this important item taking into account the real life setting. Aims: to assess real life temporal changes in respiratory diseases/symptoms (asthma, allergic rhinitis - AR - and chronic obstructive pulmonary disease - COPD) and associated risk factors in general population samples investigated during a period of 30 years. Methods: a general population sample from 4 studies (PISA1: 1985-1988; PISA2: 1991-1993; PISA3: 2009-2011; AGAVE: 2011-2014), completing a questionnaire on respiratory symptoms/diseases, risk factors exposure and performing spirometry and skin prick test, was analyzed. Respiratory symptoms/diseases cumulative incidence, remission, persistence, multimorbidity and phenotypes were computed. Cross-sectional risk factors exposure (smoking habits, occupational exposure, vehicular traffic exposure) and longitudinal changes in risk factors exposure (incidence, persistence, remission) were considered. Multiple logistic regression, multinomial logistic regression and latent transition analyses were run to assess the relationship between respiratory disease outcomes and risk factors exposure. Results: substantial temporal changes in respiratory symptoms/diseases in general population samples were found: respiratory symptoms/diseases new onset ranging from 3.4% for asthma to 33.1% for AR; 52.5% of asthma remission and 39.6% of COPD remission; 17.2% of asthma underdiagnosis and 30.4% of COPD underdiagnosis (defined as symptoms persistence without lifetime physician diagnosis); 18.6% of respiratory multimorbidity new onset. Moreover, the following longitudinal trajectories of respiratory symptoms/diseases phenotypes were computed over 18 years: 2% improving health status, 52.2% persistent health status, 22.9% persistent AR, 9% persistent usual cough/phlegm, 13.8% worsening health status. Temporal changes (i.e. persistence and incidence) in lifetime habits and in exposure to risk factors were differently associated with the temporal changes in respiratory diseases occurrence in a real life setting. Smoking habits were related to: persistent disease condition, in particular persistent usual cough/phlegm phenotype; worsening health status due to new onset of usual cough/phlegm, COPD and respiratory mutimorbidity. Occupational exposure was related to: persistent medical condition, in particular persistent usual cough/phlegm phenotype; new onset of respiratory multimorbidity and morbidity, in particular of allergic diseases and bronchitic symptoms/diseases. Vehicular traffic exposure was related to: new onset of respiratory multimorbidity and morbidity, in particular of allergic diseases and of asthma symptoms. Moreover, passive smoke exposure and occupational exposure reduced the probability of asthma remission; living in an urban area reduced the probability of asthma and COPD remission; smoking habits seemed to facilitate COPD diagnosis, while masking asthma diagnosis. Comorbidities reduced the probability of asthma and COPD remission and facilitated COPD diagnosis. Conclusions: few longitudinal studies on general population are available in literature; the Pisa survey permitted to assess an important topic, like the increase of respiratory symptoms/diseases, addressing different and specific aspects, with different methodological approaches, and adding new scientific evidences. The obtained results should be considered for primary prevention strategies in order to reduce the burden of chronic diseases in the general population and for prevention and management strategies of respiratory diseases in health care setting.