Asthma Med Adherence: Do High Insurance Deductibles Make a Difference?

You might think that when asthma patients were switched involuntarily from regular insurance to high-deductible health plans (HDHPs), a substantial number would cut corners on their daily controller medications — but you would mostly be wrong, researchers said.

In fact, in a study of some 185,000 pediatric and adult patients with asthma spanning 2002 to 2014, average adherence (as measured by prescription refills and days covered by filled prescriptions) did not change markedly with such switches, reported Alison A. Galbraith, MD, PhD, of Harvard Medical School in Boston, and colleagues in JAMA Pediatrics.

A few comparisons did show minor but statistically significant differences. For example, adults switched to HDHPs who were using inhaled corticosteroids and long-acting beta agonist (ICS-LABA) controllers showed a 1.4% greater decrease in days covered compared with patients remaining in conventional plans (95% CI 0.3%-2.5%), though not in other adherence measures.

As well, individuals who were switched to HDHPs qualifying for health savings accounts (HSAs), which typically subject controller medications to the deductible, had a 4.8% greater reduction in days covered (95% CI 1.9%-7.7%) compared with non-HSA HDHP enrollees, for whom such drugs are typically exempted from the deductible. It was the only major difference between groups in that analysis, too.

Moreover, those reductions in adherence did not seem to raise the risk of exacerbations. Claims data showed that neither asthma-related emergency department visits nor prescriptions for oral corticosteroids (often serving as rescue medications) differed between patient groups, whether stratified by HDHP versus conventional plans or by HSA versus non-HSA HDHP.

Previous studies of HDHPs and asthma drug use had yielded mixed results, Galbraith and colleagues said, though an adverse effect of high deductibles has long been suspected.

An accompanying editorial by two specialists from Lurie Children’s Hospital of Chicago said the new findings “may be somewhat reassuring to skeptics of HDHPs.”

But authors Jennifer Kusma, MD, MS, and Matthew M. Davis, MD, MAPP, added that the study doesn’t fully lay the suspicions to rest.

For example, they wrote, it’s unknown how many children overall are enrolled in HDHPs that don’t exempt asthma controller drugs from the deductibles. And neither the current study nor others have addressed HDHPs’ policies on medications for other chronic conditions, which might not be as generous as is the case for asthma controllers.

Galbraith and colleagues noted other limitations, too. It’s possible, they wrote, that the reductions in adherence were concentrated in patients at low baseline risk for exacerbations, who may have believed correctly that they could safely skip doses of their controller medications.

Taken at face value, however, the study’s findings support so-called value-based health policies that emphasize prevention and cost-effectiveness in determining what insurance should pay for, according to both the study authors and the editorialists.

“Policymakers should consider adopting value-based designs and other policies that exempt important medications for asthma and other chronic conditions from the deductible, which might prevent adverse clinical outcomes in HDHPs,” Galbraith and colleagues wrote.

For their part, Kusma and Davis said, “Policy makers must consider further what other components of health care should be exempted from deductibles in HDHPs in an effort to minimize risks and maximize benefits for children enrolled in such plans.”

Study Details

Galbraith’s group drew on data from a claims database covering adults (up to age 64) and children (ages 4-17) enrolled in employer-sponsored commercial plans over a 13-year period beginning in 2002. Patients included 7,275 children and 17,614 adults whose plans changed to HDHPs from more conventional low-deductible designs, who were then compared with control groups comprising more than 45,000 children and 114,000 adults remaining in conventional plans.

HDHPs were defined as those plans with deductibles of at least $1,000. They were further divided into those eligible for HSAs under federal regulations (which changes yearly, currently at deductibles of $1,400 or more) and those not; 10% of patients in the study had HSA HDHPs. These plans typically do not exempt controller drugs from the deductible, but assume patients will pay for them out of their HSAs. (Non-HSA HDHPs may still impose controller drug costs on enrollees, in the form of copayments, Galbraith and colleagues noted.)

Two related measures of adherence were monitored: the rate of 30-day refills of standard asthma controller medications, including ICS-LABA drugs, ICS alone, or leukotriene inhibitors such as montelukast (Singulair); and the proportion of days covered by these agents.

For all three medication types, the latter measure showed substantial declines over time in both groups, those switched to HDHPs and those not. But these declines were of similar magnitude in both groups, suggesting that HDHPs were not responsible. Both groups as well showed declines, not increases, in point estimates for adverse clinical outcomes including use of oral corticosteroids and asthma-related emergency visits.

Galbraith and colleagues also examined neighborhood affluence as a potential factor in patients’ reactions to HDHPs. Roughly 40% of individuals in the study lived in low-income neighborhoods. Adherence patterns in these patients were generally the same as in the overall study, with some slightly greater reductions among those switched to HDHPs, but no higher rates of adverse clinical outcomes recorded in claims data.

The researchers noted that these data don’t necessarily cover all adverse outcomes: days out of work or school, for example would be missed, as would increases in symptoms that didn’t result in a new prescription or emergency room visit. As well, socioeconomic data were available only for neighborhoods and not for individuals.