Nearly one in three British Columbia women over age 65 received inappropriate levels of prescription medicines in 2013, while only one in four men of the same age did, according to a new paper.

The work analyzed population-based health-care datasets to find out which medical and non-medical factors influence patients' risk of receiving prescription drugs on the American Geriatrics Society's list of drugs that should be avoided for older patients. The biggest non-medical risk factor was an individual's sex.

The authors found that, even when results were adjusted for all other risk factors, women were as much as 23 per cent more likely than men to be prescribed inappropriate drugs.

Despite increased awareness among doctors and pharmacists of the harms associated with prescribing certain medications to older patients, the study found older British Columbians continue to routinely receive inappropriate prescriptions. The study also found that women were much more likely to receive medications in general than men.

"The effect of a patient's sex on the risk of inappropriate prescribing is of tremendous clinical and social concern," said Steve Morgan, professor in University of British Columbia's school of population and public health and principal investigator for the study. 

"Being a woman is double jeopardy when it comes to taking medications," said Dr. Cara Tannenbaum, scientific director of the Canadian Institutes of Health Research's Institute of Gender and Health. "Women metabolize drugs differently than men. Gender roles and social circumstances also place them at risk. However, I expect that by empowering women with knowledge about the harms of sleeping pills and other medications, we can help drive decisions to try switching to safer therapies."

The findings of this study - including sex differences in the effects of income, ethnicity, and marriage - suggest that the elevated risks that women face are a result of complex issues intersecting between social, gender and authority relationships.

"For men, being married or in a high income bracket reduced the risk of receiving inappropriate prescriptions. These factors had no significant effect for women. On the other hand, being Chinese or South Asian significantly lowered women's risk of receiving an inappropriate prescription, but did not affect men's risks," said Morgan.

The authors believe that the sex differences in older adults' risk of receiving a potentially inappropriate prescription are significantly influenced by social dynamics, including differences in patients' care seeking and care-giving behaviors, as well as differences in the relationships and communications between patients and providers.

The study authors speculate that solutions to the problem of potentially inappropriate prescribing will require investment in conventional, clinical tools to assist with de-prescribing potentially inappropriate medications. They also recommend that more nuanced solutions will be needed to address how gender - on its own and interacting with age, wealth and ethnicity - affect the norms of and relationships between prescribers and patients.