Private health plans’ use of cost sharing for prescription drugs – the practice of shifting more of the expense of medications onto the patient – apparently has led parents of children with asthma to reduce their use of control therapy, according to a report in the March 28 issue of JAMA.
Higher out-of-pocket medication costs correlated with a significant reduction in the percentage of days covered by an asthma medication among privately insured children aged 5-18 years, and a simultaneous rise in the number of asthma-related hospitalizations, said Pinar Karaca-Mandic, Ph.D., of the division of health policy and management at the University of Minnesota School of Public Health, Minneapolis, and her associates.
Numerous studies have examined the effect of medication cost sharing on adults, consistently linking it to reduced medication use and increases in hospitalizations and emergency department visits. However, the effects on children "have been overlooked."
Dr. Karaca-Mandic and her colleagues used data on pharmacy and medical claims from a benefits consulting firm to assess how out-of-pocket drug costs affected these factors in children newly diagnosed with persistent asthma requiring long-acting control therapy.
They analyzed data on 8,834 de-identified patients covered by private health insurance provided by 37 geographically diverse U.S. employers from 1997 through 2008. The children were prescribed inhaled corticosteroids, long-acting beta-agonists, leukotriene receptor antagonists, methylxanthines, cromolyn sodium, and immunomodulators to be taken every day year-round.
The investigators followed the patients for 1 year, determining the percentage of days in which these asthma control drugs were supplied. They also calculated parents’ mean out-of-pocket costs for the drugs.
Since asthma is managed somewhat differently as children age, the researchers divided their study subjects into younger (2,921 subjects younger than 5 years) or older (5,913 subjects aged 5-18 years) groups. Approximately 60% of both age groups were prescribed more than one asthma medication.
The mean use of asthma control medications was low in both age groups, at 40%-46% of the year, Dr. Karaca-Mandic and her associates said (JAMA 2012;307:1284-91).
In the older age group, higher out-of-pocket drug costs were associated with a significant reduction in percentage of days covered by an asthma control medication, from approximately 42% to 40%. This association was not seen in younger children.
Similarly, in the older age group, higher out-of-pocket drug costs were associated with a significant increase in asthma-related hospitalizations but not other hospitalizations, from 1.7 to 2.4 per year. This association also was not seen in younger children.
Out-of-pocket drug costs did not significantly affect rates of ED visits in either age group.
The lack of an association between drug costs and drug usage in younger children "suggests that parents may be less sensitive to medication costs for younger children, who traditionally have more severe disease. In addition, parents may play a more active role in disease management for younger children with asthma compared with that for adolescents," the researchers said.
Overall, the study findings indicate that "greater prescription medication cost sharing among children with asthma may lead to small reductions in use of important medications, with unintended consequences of more frequent asthma-related hospitalizations," they said.
This study was limited in that it did not include information on family income or on asthma severity, the researchers added.
This study was funded by the National Institute of Child Health and Human Development, the National Institute on Aging, and the Roybal Center for Health Policy Simulation. Dr. Karaca-Mandic reported no financial conflicts. Her associates reported ties to Precision Health Economics, Pfizer, Novartis, and Bristol-Myers Squibb.