Relation of lung function and exercise capacity to mood and attitudes to health.

Results of psychometric tests were obtained on 161 male welders and other tradesmen in heavy industry who had recently been made redundant. Anxiety and depression were scored on the Hospital Anxiety and Depression Scale, and negative attitudes and beliefs regarding breathlessness and related aspects of respiratory health on a semantic differential scale. Scores for attitudes and beliefs about health and personal disability were pooled to give a general attitude score. Personality was rated on a standard scale. Subjects completed a questionnaire on respiratory symptoms and underwent routine spirometry, measurement of carbon monoxide transfer factor for the lung, and a progressive exercise test on a cycle ergometer. Scores for anxiety, depression, and negative mental attitudes were significantly intercorrelated; subjects with disordered personality profiles had above average scores for anxiety and depression. The psychometric scores were associated with clinical grade of breathlessness, lung function, and the physiological response to exercise. The general attitude score could be predicted from the anxiety and depression scores and from lung function expressed relative to age and stature, the combination of mood score and FEV1 explaining 38% of the variance in general attitude score. The general attitude score accounted for more than half the explained variance in the clinical grade of breathlessness and contributed more to the variance in maximal oxygen uptake (R2 = 0.11) than FEV1. It was associated with the level of habitual activity but not with smoking category, wheeze, chronic cough or phlegm. Thus attitude to disability reflected the subject's assessment of his exercise capacity and was closely related to the clinical grade of breathlessness.