Purpose: Although health-related quality of life in older people is generally assessed by measuring specific domains of health status, such as activities of daily living or pain, the association between health-status measures and patients' perceptions of their quality of life is not clear. Indeed, it is controversial whether these health-status measures should be considered measures of quality of life at all. Our objective was to determine the association between health-status measures and older patients' perceptions of their global quality of life.
Subjects and methods: We performed a cross-sectional study of 493 cognitively intact patients 80 years of age and older, interviewed 2 months after a hospitalization. We measured patients' self-assessed global quality of life and four domains of health status: physical capacity, limitations in performing activities of daily living, psychological distress, and pain.
Results: Each of the four scales was significantly correlated with patients' global perceptions of their quality of life (P <0.001). The ability of the health-status scales to discriminate between patients with differing global quality of life was generally good, especially for the physical capacity (c statistic = 0.72) and psychological distress scales (c statistic = 0.70). However, for a substantial minority of patients, scores on the health-status scales did not accurately reflect their global quality of life. For example, global quality of life was described as fair or poor by 15% of patients with the highest (best tertile) physical capacity scores, 25% of patients who were independent in all activities of daily living, 21% of patients with the least psychological distress (best tertile), and by 30% with no pain symptoms. Similarly, global quality of life was described as good or better by 43% of patients with the worst physical capacity (worst tertile), 49% of patients who were dependent in at least two activities of daily living, 47% of patients with the most psychological distress (worst tertile), and 51% of patients with severe pain.
Conclusion: On average, health status is a reasonable indicator of global quality of life for groups of older patients with recent illness. However, disagreement between patients' reported health status and their perceptions of their global quality of life was common. Therefore, assumptions about the overall quality of life of individual patients should not be based on measures of their health status alone.