COLUMBUS, Ohio - Middle-aged women who suffered physical or sexual abuse as children spend up to one-third more than average in health-care costs, according to a long-term study of more than 3,000 women.
Even decades after the abuse ended, these women used health services at significantly higher rates than did non-abused women, the research found.
"What's remarkable is that women with an average age in their late 40s still suffer consequences from abuse that occurred decades ago," said Amy Bonomi, associate professor of human development and family science at Ohio State University, who led the study at Group Health in Seattle.
"No other study has found that before."
Women who had no history of abuse spent an average of $2,413 a year (in 2004 dollars) on health care costs. Women who were sexually abused only paid an average of $382 a year more, those who were physically abused spent $502 more, and women who suffered both types of abuse spent $790 a year in additional health care costs.
The study appears online in advance of the March issue of the Journal of General Internal Medicine.
The study took into account factors such as age and education that also can affect health care use. "We are able to say pretty confidently that it was the abuse itself that is driving higher health care use and costs in these women," she said.
After accounting for women's age and education, women who were sexually abused as children faced health care costs 16 percent higher than non-abused women, while physically abused women's costs were 22 percent higher. For women who suffered both types of abuse, costs rose 36 percent above average.
The research examined data from 3,333 women who belonged to Group Health, a health care system in the Pacific Northwest.
While other studies had linked childhood abuse to higher adult health care costs, this research provides the most comprehensive and accurate evidence to date, Bonomi said.
For one, it includes actual health care data on the women, complete with physician visits and pharmacy use. Other studies have relied on participants to report their health care use.
This study also included a large sample of women, and looked at them over a long period of time -- an average of 7.5 years per woman. In addition, while many studies have only examined women up to the mid to late 30s, this study included women with an average age of 47.
"This study provides the strongest evidence to date about the impact of abuse well into adulthood," Bonomi said.
Overall, the study found that 34 percent of women reported some type of childhood abuse, which is similar to rates found in other studies.
As would be expected, women who had been abused were more likely than others to be diagnosed with depression. They also reported more physical symptoms and were more likely to have a higher body mass index, a sign of obesity. Abuse was not associated with other chronic conditions such as heart disease, diabetes or asthma.
Women who had suffered both physical and sexual abuse had higher health service use in six areas: mental health, hospital outpatient, emergency department visits, primary care, specialty care, and pharmacy fills.
Those who were only physically abused or only sexually abused had higher use in four of the health service areas.
"It's not surprising that abuse victims had higher use of primary, specialty and mental health care services," said Bonomi. "But it is somewhat surprising that women who were physically abused and those who experienced both types of abuse were also more likely than others to visit the emergency room."
Bonomi said the results reinforce the need for abuse prevention programs that target parents of young children who are at risk of child abuse. Soon-to-be parents should also receive attention. In addition, the findings suggest health care professionals should screen adults for child abuse history, particularly people with high levels of health care service use.
While this study was funded to look specifically at women, Bonomi said she and her colleagues are currently examining how childhood abuse affects adult health care use and costs in men.
Group Health, the health care system whose members were surveyed for the study, provides health and insurance services to more than 500,000 people in the Pacific Northwest.
Bonomi conducted the study with Melissa Anderson, Paul Fishman, David Carrell, Robert Reid and Robert Thompson of Group Health Center for Health Studies in Seattle; Frederick Rivara of the Harborview Injury Prevention and Research Center and the University of Washington; and Elizabeth Cannon, a graduate student at Ohio State.
The study was funded by the federal Agency for Healthcare Research and Quality.