Relationship between anxiety, depression, and morbidity in adult asthma patients

Background-Symptoms of disease reported by patients reflect the effects of the disease process within the individual and the person's physical and men tal ability to tolerate or otherwise cope with the limitations on their fun ctioning. This study examines the relationship between asthma symptoms, dis ease severity, and psychological status in patients being managed in routin e primary healthcare settings. Methods-One hundred and fourteen subjects from four GP practices, two inner city and two suburban, were studied. Symptoms were assessed by means of th e Asthma Quality of life questionnaire (AQLQ) and a locally devised Q score , and psychological status with the Hospital Anxiety and Depression (HAD) s cale. Spirometric values and details of current asthma treatment (BTS asthm a guidelines treatment step) were recorded as markers of asthma severity. Results-Symptoms as measured by AQLQ correlated with peak expiratory flow ( r(s) = 0.40) and with BTS guidelines treatment step (r(s) = 0.25). Similarl y, the Q score correlated with peak expiratory flow (r(s) = 0.44) and with ETS guidelines treatment step (r(s) = 0.42). Similar levels of correlation of forced expiratory volume in one second (FEV1) with symptoms were reporte d. HAD anxiety and depression scores also correlated to a similar extent wi th these two symptom scores, but there was hardly any correlation with lung function. Logistic regression analysis showed that HAD scores help to expl ain symptom scores over and above the effects of lung function and BTS guid elines treatment step. Symptoms, depression, and anxiety were higher for in ner city patients while little difference was observed in objective measure s of asthma. Conclusions-Asthma guidelines suggest that changing levels of symptoms shou ld be used to monitor the effectiveness of treatment. These data suggest th at reported symptoms may be misleading and unreliable because they may refl ect non-asthma factors that cannot be expected to respond to changes in ast hma treatment.