The influence of anxiety and depression on respiratory drug consumption in a general population sample

Rationale: anxiety and depression are two common comorbidity in subjects with respiratory diseases. The present work is aimed at evaluating, in an Italian general population sample, the influence of anxiety/depression on respiratory drug consumption in subjects with asthma/COPD. Methods: within the European Union funded project IMCA2 (Indicators for Monitoring COPD and Asthma in the EU), a sample of subjects living in Pisa (Central Italy) was selected. An information technology tool allowed to record spirometry and to fill in a core questionnaire on socio-demographic characteristics, respiratory symptoms/diseases, risk factors and anxiety/depression. The Hospital Anxiety and Depression Scale (HADS) was used to obtain confirmation in the anxiety/depression diagnoses. Statistical analyses were performed using the statistical package SPSS 13.0. 'Asthma' is identified by having a previous medical diagnosis or wheezing/whistling, attacks of shortness of breath with wheezes and nocturnal attacks of shortness of breath. 'COPD' is identified by having a previous medical diagnosis of chronic bronchitis, emphysema or chronic cough, chronic phlegm and dyspnoea >= II level. A multinomial logistic regression analysis, adjusted for smoking habits, age, sex, medical examination, was run to assess association between respiratory drug consumption or other drug consumption and: asthma/COPD with anxiety/depression ('AC-AD'); asthma/COPD without anxiety/depression ('AC'); anxiety/depression without asthma/COPD ('AD'); neither anxiety/depression nor asthma/COPD ('NN'). Subjects who didn't use any drug were the reference category. Results: 80.1% of contacted subjects participated (n=977). Analyses concerned 903/977 subjects who filled in HADS questionnaire (mean age:56.5 yrs±18.0; 45.3% male). 7.0% of subjects had 'AC-AD', 27.8 % 'AC', 9.4% 'AD': 30.2% of subjects with 'AC-AD' used respiratory drugs compared to 21.1% of subjects with 'AC' and no subject with only 'AD'. Respiratory drug consumption was significantly associated with 'AC' (OR=12.14; 95% CI=5.56-26.52) and 'AC-AD' (OR=15.21; 95% CI=4.28-53.99). Use of respiratory drugs was also significantly associated with female gender (OR=2.37; 95% CI=1.22-4.60) and medical examination because of breathing problems/shortness of breath (OR=9.25; 95% CI=4.22-20.27). Moreover 'AC', 'AC-AD' and 'AD' were significantly associated with other drug consumption: OR=2.58 (95% CI=1.64-4.06), OR=3.46 (95% CI=1.25-9.51) and OR=2.42 (95% CI=1.33-4.42) respectively. Use of other drug was also significantly associated with age: 46-64 yrs (OR=2.59; 95% CI=1.56-4.31) and >=65 yrs (OR=8.41; 95% CI=4.84-14.60).