When asked to rate their own health, women, on average, consistently report being in worse health than men do, and a new study from researchers in Spain says this is because women have a higher rate of chronic diseases — contradicting a previous theory that women's lower self-rated health is simply a reporting bias.
"In general practice, there has been this idea that women over-report health problems, or are more likely to say they are ill or pay attention to their symptoms than men," said first author of the study Davide Malmusi, of the Public Health Agency of Barcelona. "We wanted to test whether their differences in self-reported health could in fact be explained by the difference in the prevalence of chronic conditions."
The new findings were published Dec. 16 in the European Journal of Public Health.
Malmusi and colleagues across Spain gathered data from Spain's 2006 National Health Survey, which included data from face-to-face interviews with more than 29,000 people on their health. About half of the study participants were between the ages of 16 and 44; the other half was older.
The survey included the question, "Over the last 12 months, would you say your overall health has been very good, good, fair, poor, or very poor?" as well as a question on whether health problems had limited people's activities over the previous six months.
Of the women interviewed, 38.8 percent rated their health as poor or very poor, and 25.7 percent reported chronic limitation of activity. Of the men in the study, only 27 percent had poor self-rated health, and 19.3 percent reported chronic limitation of activity.
But when the researchers matched up the number of chronic conditions each person had with his or her health rating, the gender difference disappeared. Having a higher number of chronic conditions correlated with poorer self-rated health to the same degree in both genders.
For men and women with the same conditions, or the same number of conditions, women were no more likely to claim poorer health.
"There's been a longstanding debate about whether women's self-reported health is a reporting bias or not," said sociologist Ellen Annandale of the University of Leicester in the United Kingdom, who was uninvolved in the new work. "Some researchers argue that women might over-report health problems, and men might under-report. This study supports wider research that women's poorer self-reported health reflects underlying chronic health problems."
The root of chronic health problems
What the new study doesn't answer, Annandale said, is why women have a higher rate of chronic health problems. The data did reveal that women's higher rate of chronic problems can be most strongly attributed to five chronic disorders: arthritis, mental disorders, neck pain, headaches and back pain. But further research will be needed to explain why.
Malmusi said it is likely a mix of biological and social factors.
"Gender influences that way that people are treated and diagnosed in health systems," Annandale said. "It influences the kind of health conditions that men and women suffer from, the way people relate to their own bodies, and what kind of access to health care they have."
Understanding gender differences in health can help scientists and doctors find ways to better treat patients, she said.