Analysis of longitudinal changes in the psychological status of patients with asthma

Significant relationships between the psychological status and poor asthma outcomes are often reported. However, most of these studies are cross-sectional and none have evaluated how the psychological status progresses over time during the management of asthma patients. Therefore, we examined the longitudinal changes in the psychological status of asthma patients, and compared them with changes in other clinical measurements. Eighty-seven outpatients with stable asthma after 6 months of treatment were enrolled in this study. The psychological status was evaluated using the Hospital Anxiety and Depression Scale (HADS), the health status using the Asthma Quality of Life Questionnaire (AQLQ) and the St. George's Respiratory Questionnaire (SGRQ). The patient's pulmonary function, peak expiratory flow values and airway hyperresponsiveness were measured at entry and every year thereafter over a 5-year period. Using mixed effects models to estimate the slopes, the HADS anxiety and depression scores did not change significantly over time (p=0.71 and 0.72, respectively). The changes in the HADS scores correlated noticeably with changes in the AQLQ and SGRQ scores, but not with changes in the physiological measurements. The baseline HADS anxiety and depression scores were significantly correlated to the subsequent annual changes in each measurement. The psychological status remained clinically stable over the 5-year study period in patients with stable asthma. Changes in the psychological status were significantly correlated to changes in the health status. The baseline HADS scores were a useful indicator in detecting patients who would show subsequent deterioration in their psychological status.