Older men at greater risk of serious events, including hospitalization and death, after starting new antipsychotic drug therapy

09/01/2013

Very little is known about the way older women and men differ in their response to drug therapy. That’s why researchers at the Institute for Clinical Evaluative Sciences (ICES) and Women’s College Research Institute conducted a new study investigating the risk of a serious event (hospitalization or death) following the initiation of antipsychotic therapy. They found that older men with dementia are more likely to experience a serious event than women.

“Understanding how drug therapy affects older women and men differently is important,” said Dr. Paula Rochon, study investigator and senior scientist at Women’s College Research Institute and at ICES. “It can impact the treatment decisions physicians make regarding prescribing drug therapy for their patients.”

Antipsychotic drug therapy has been associated with serious events that can occur shortly after the initiation of the therapy.

The population-based, retrospective cohort study looked at 21,526 older adults (13,760 women and 7,766 men) with dementia newly started on an oral atypical antipsychotic therapy between April 1, 2007 and March 1, 2010 in Ontario and found that:

Nearly 9 per cent had a serious event (7.6 per cent of women and 10.9 per cent of men).
In the group studied, 2.6 per cent of women and 4.6 per cent of men died.
Relative to women, men were almost 50 per cent more likely to be hospitalized or die.
Men were consistently more likely to experience a serious event based on analyses that considered setting of care, age group, Charlson comorbidity score and antipsychotic dose.
A gradient of risk by drug dose was found for the development of a serious event in both women and men.

“We tested whether our findings of differences between women and men could be explained by factors including their setting of care, age distribution, comorbidity or drug dose,” added Dr. Rochon. “In each stratum, men were significantly more likely than women to experience a serious event, leading us to believe that there are other reasons why older men experience worse outcomes than women when they are newly prescribed antipsychotic therapies. More research in this area is recommended.”

The authors stress that the risk of developing a serious event shortly after the initiation of antipsychotic therapy was higher in men than women of advanced age does not imply that vigilance regarding antipsychotic risks should be any less for older women than for older men.

Authors: Paula A. Rochon, Andrea Gruneir, Sudeep S. Gill, Wei Wu, Hadas D. Fischer, Susan E. Bronskill, Sharon-Lise T. Normand, Peter C. Austin, Dallas P. Seitz, Chaim M. Bell, Longdi Fu, Lorraine Lipscombe, Geoffrey M. Anderson, Jerry H. Gurwitz.

The study “Older men with dementia at greater risk than women of serious events after initiating antipsychotic therapy” was published today in the Journal of the American Geriatrics Society (JAGS).

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

Women’s College Research Institute (WCRI), part of Women’s College Hospital (WCH), is dedicated to developing medical insights that enhance the health of women and improve health-care options for all. Fully affiliated with the University of Toronto, WCRI scientists lead research that translates into better clinical care that impacts people in Toronto, across Canada and around the world. For more information about how Women’s College Research Institute is transforming patient care, visit www.womensresearch.ca.