Dyspnea as an independent predictor of mortality

Dyspnea is a common and easily elicited presenting complaint in patients seen by physicians who evaluate and take care of chronic respiratory disorders. Although dyspnea is subjective and tends to increase with age or reduced lung function, it appears to be reproducible as a symptom and often signifies serious underlying disease.

Systematic review of longitudinal studies with dyspnea as the exposure and mortality as the outcome; age, smoking and lung function had to be controlled for to be included in the review. In addition, a minimum sample size at baseline of 500 subjects was required for each study.

From over 3000 potential references, 10 longitudinal studies met all criteria and were included. All 10 studies suggested that dyspnea was an independent predictor of mortality with point estimates by odds ratio, rate ratio or hazard ratios ranging from 1.3 up to 2.9-fold greater than baseline. All 10 studies had actual or implied 95% confidence interval bands greater than the null value of one.

Dyspnea, a symptom, predicts mortality and is a proxy for underlying diseases, most often of heart and lung. Therefore, chronic dyspnea needs to be evaluated as to etiology to allow for treatment to minimize morbidity and mortality when possible.