Adults who self-rated their health as poor in middle age were at least three times more likely to die or be hospitalized when older than those who self-rated their health as excellent, based on data from nearly 15,000 individuals.
Previous research has shown that self-rated health is an independent predictor of hospitalization or death, but the effects of individual subject-specific risks on these outcomes has not been examined, wrote Scott Z. Mu, MD, of the Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, and colleagues.
In a study published in the Journal of General Internal Medicine, the researchers reviewed data from 14,937 members of the Atherosclerosis Risk in Communities (ARIC) cohort, a community-based prospective study of middle-aged men and women that began with their enrollment from 1987 to 1989. The primary outcome was the association between baseline self-rated health and subsequent recurrent hospitalizations and deaths over a median follow-up period of 27.7 years.
At baseline, 34% of the participants rated their health as excellent, 47% good, 16% fair, and 3% poor. After the median follow-up, 39%, 51%, 67%, and 83% of individuals who rated their health as excellent, good, fair, and poor, respectively, had died.
The researchers used a recurrent events survival model that adjusted for clinical and demographic factors and also allowed for dependency between the rates of hospitalization and hazards of death.
After controlling for demographics and medical history, a lower self-rating of health was associated with increased rates of hospitalization and death. Compared with individuals with baseline reports of excellent health, hospitalization rates were 1.22, 2.01, and 3.13 times higher for those with baseline reports of good, fair, or poor health, respectively. Similarly, compared with individuals with baseline reports of excellent health, hazards of death were 1.30, 2.15, and 3.40 for those with baseline reports of good, fair, or poor health, respectively.
Overall, individuals who reported poor health at baseline were significantly more likely than those who reported excellent health to be older (57.0 years vs 53.0 years), obese (44% vs 18%), and current smokers (39% vs 21%). Those who reported poor health at baseline also were significantly more likely than those who reported excellent health to have a history of cancer (9.5% vs 4.4%), emphysema/COPD (18% vs 2.3%), coronary heart disease (21% vs 1.6%), myocardial infarction (19% vs 1.3%), heart failure (25% vs. 1.2%), hypertension (67% vs 19%), or diabetes (39% vs 4.6%).
Potential explanations for the independent association between poor self-rated health and poor outcomes include the ability of self-rated health to capture health information not accounted for by traditional risk factors, the researchers wrote in their discussion. “Another explanation is that self-rated health reflects subconscious bodily sensations that provide a direct sense of health unavailable to external observation,” they said. Alternatively, self-rated health may reinforce beneficial behaviors in those with higher self-rated health and harmful behaviors in those with lower self-rated health, they said.
The findings were limited by several factors including the measurement of self-rated health and the validity of hospitalization as a proxy for morbidity, the researchers noted. Other limitations include the use of models instead of repeated self-rated health measures, and a lack of data on interventions to directly or indirectly improve self-rated health, the researchers noted.
However, the study shows the potential value of self-rated health in routine clinical care to predict future hospitalizations, they said. “Clinicians can use this simple and convenient measure for individual patients to provide more accurate and personalized risk assessments,” they said.
Looking ahead, the current study findings also support the need for more research into the routine assessment not only of self-rated health but also targeted interventions to improve self-rated health and its determinants, the researchers concluded. The ARIC study has been supported by the National Heart, Lung, and Blood Institute, National Institutes of Health. Dr. Mu disclosed support from the National Heart, Lung, and Blood Institute.