Background: Quality of life (QOL) is a major goal in the context of preventive and therapeutic cardiology. In this article, quality of life concepts are reviewed, factors limiting QOL in cardiac disease are identified, methods of measurement are explored, and clinically significant changes are defined. The changes effected by cardiac rehabilitation are considered, together with their physiological and psychological correlates. A final section suggests avenues for future research.
Methods: Relevant articles were identified by computer literature searches and review of extensive personal files.
Findings: In the past, there has been an excessive focus on extending the length rather than the quality of the cardiac patient's life. The overall QOL is a broad concept, influenced by personal perceptions, coping mechanisms, and environmental constraints. The ideal test instrument would be reliable, valid, and responsive to clinical change. Potential options include a Gestalt-type instrument, a disease-specific instrument, a function-specific instrument, or a detailed generic questionnaire. There have been relatively few comparisons between these potential approaches. Currently, the Standard Gamble (Gestalt-type), and Living With Heart Failure Questionnaire (disease-specific type), and the Medical Outcomes Study Short-Form 36 (SF-36) Health Survey (generic-type) are among the most popular approaches. Problems arise in distinguishing a clinically important from a statistically significant change; commonly a score change of 1 standard error of the mean is regarded as clinically important. Correlations of scores with clinical, physiological, and psychological change are sometimes weak, in part because of floor and ceiling effects. Nevertheless, potential gains in QOL provide a stronger argument for preventive and therapeutic programs than do increases in longevity.
Conclusions: The current literature supports the value of QOL measurements in the management of patients with cardiac disease. However, further research is needed to determine the optimum test instrument, and the best method of interpreting resultant scores.