Perceived Health

Various criteria are used to assess a person's level of health. Objective measures can be noted and counted by a trained observer, while subjective measures of health depend exclusively on a person's self-evaluation. Objective measures include the presence of a disease or disorder, measuring of blood pressure, days spent in bed or in the hospital, or observation of the ability of the person to perform daily activities. A subjective measure of assessed health can be collected by simply asking a person if his or her health is excellent, good, fair, or poor. Both objective indicators and the subjective measure of self-rated health are designed to capture the health status of an individual, and there is a moderately strong relationship between the two measures. Most people report an evaluation of their health that matches or comes close to the objective indicator of a physician's diagnosis. In general, those with more functional disabilities are likely to rate their health less favorably. In addition, those with specific chronic conditions, such as heart disease, chronic lung problems and diabetes also report worse health.

However, one landmark study (Maddox and Douglass, 1973) reported that about a third of its sample perceived their health as being much better or much worse than a physician's objective rating. Instead of viewing self-rated health as a measure that is somewhat helpful in determining health status, though biased by psychological states, the researchers tested whether it offered any information beyond that provided by objective measures. One way of evaluating measures of health is to see how well they predict one's risk of death in a given period of time. Overall, people with objective indicators of health problems are at a greater risk of dying in the next few years than those who do not have health problems. To test whether self-rated health also predicts mortality, and if it provides any information beyond that of objective indicators, Mossey and Shapiro (1982) examined information about people's self-rated health, physicians' reports for each individual based on objective measures, and a record of whether or not each person died within the next six years. After being matched in terms of physician's health reports, those who rated their health as poor had a three times greater risk of dying in the next few years than those who rated their health as excellent. Furthermore, self-rated health was a more powerful predictor of mortality than the physician's objective measures.

Idler and Benyamini (1997) reviewed the international literature on self-rated health as a predictor of mortality for noninstitutionalized individuals. Overall, the results overwhelmingly supported the association between self-rated health status and mortality, even when other objective indicators of health status were considered. Several interpretations of such findings are possible. First, it may be that self-rated health is a more accurate measure because it captures more than is possible by considering typical objective indicators. When rating one's health, a person may consider symptoms that are not yet diagnosed, weigh the severity of symptoms, or consider family history and expected longevity. Second, self-ratings of health may include not only one's current level of health, but also the trajectory of decline or improvement in health. In fact, when researchers have access to an individual's health status at various points in time, a change in health status predicts mortality, explaining part of the predictive power of self-rated health. Third, a person's perception of his or her health may influence or reflect health behaviors. A person with a poor perception of health may not bother with preventive measures such as diet and exercise, while people with good perceptions of health are more likely to engage in healthful behaviors. In this way, self-rated health may be a reflection of lifestyle. Fourth, self-rated health may represent a person's evaluation of resources available to deal with health problems, either from the social environment or from within themselves. An evaluation of poor health may indicate an underlying depression that is detrimental to the immune system.

In addition to being predictive of mortality, self-rated health also predicts other outcomes, such as decline in functional ability or a greater likelihood of entering a nursing home. Even after accounting for the seriousness of the disease and the level of functional ability when the self-evaluation of health was made, elderly persons who rated their health as less than excellent were more likely than those with excellent self-rated health to be disabled, institutionalized, or dead within the next six years (see Mor et al., 1994). Research by Idler and Kasl (1995) similarly found that older adults who rated their health as poor were two and a half times as likely as those with excellent self-rated health to experience a decline in functional ability. They noted that the risk of decline was greatest for elderly persons who were relatively younger and without disability and yet still rated their health as poor. Further analysis showed that it is not positive thinking that improves the condition of the disabled, but rather negative evaluations that are linked to a decline in functioning. Other researchers have found that the perception of control illuminates the relationship between self-rated health and mortality. Older adults who reported excellent health were more likely than those who reported poor health to perceive a sense of control over their lives and to use active strategies in dealing with difficulties. This suggests that elderly persons who evaluate their health as poor may give up and allow functional decline to occur, rather than actively practicing positive health behaviors and coping strategies.

Self-rated health is clearly a useful measure in assessing the health status of an individual. It is easy to collect with a simple, general question, and it seems to provide different and additional information, compared with objective measures of health. The mechanisms through which self-rated health predicts mortality still need to be explored, though it seems that the perception of control plays an important role.