Toward a general model of health-related quality of life.

A health-related quality of life (HRQOL) model that fitted data collected in previous studies from two separate samples--patients with chronic physical illness and patients with chronic mental illness--was adapted and tested on a representative sample drawn from the normal population. This model, which implied that both physical and mental health influenced number of friendships, personal growth, and job satisfaction, fitted the data very well. However, an alternative model reversing the directions of the pathways so that friendships, personal growth, and job satisfaction affected physical health and mental health, with the latter two having a mutual effect on each other, fitted the data even better. This suggests that, although a medical model of HRQOL may be more important when it comes to alleviating illness, a psychosocial model of HRQOL may be more important when it comes to maintaining health and preventing illness. Moreover, the fact that essentially the same five-factor structural model fits three distinct populations, healthy and unhealthy, suggests that there may be a general model of quality of life applicable to all populations. The implications of these findings for clinical theory, policy, and practice are discussed.