In 2009, the FDA banned the use of chlorofluorocarbons in albuterol inhalers. This meant that all of the generic inhalers (which contained CFCs) were pulled from the shelves. As pharmaceutical companies saw the ban coming, some CFC-free hydroflouroalkane (HFA) inhalers had been brought to market in the years prior. These new inhalers were, of course, branded and more expensive than generic inhalers.
A number of older studies had shown that increased cost sharing can lead to decreased medication use in children with asthma. A study last year found that when looking at adults and children, the CFC ban led to large increases in out-of-pocket costs and modest decreases in the utilization of inhalers. Although full outcomes were not known, it's assumed that decreased use of albuterol-based medications would be dangerous to people with asthma. Further, as this was a study of insured patients, it was worried that uninsured patients, facing even higher costs, might go without even more.
No research is perfect, of course. The biggest concern about this analysis was that it did not contain a control group. It was impossible, therefore, to determine if the changes seen were actually due to the CFC ban, or due to some other unrelated change.
Because of that, researchers set out to perform a more robust study, which was recently published in Health Services Research. They conducted a population-level interrupted time series analysis starting in 2007 and running through 2010. Data therefore covered two years before and two years after the implementation of the ban. The rolling cohort consisted of children age 4-17 years who had asthma, who were continuously enrolled in a commercial insurance plan with drug coverage.
As with prior studies, the main exposure of interest was a cost-sharing increase for albuterol inhalers after the CFC ban. In this study, however, the researchers were able to include a control group. Some health plans chose to keep the copays the same as for the generic inhalers before the ban even after the more expensive brand name versions became the drug of choice. This allowed them to compensate for trends in the use of inhalers that might be unrelated to the policy change.
The main outcomes of interest were the number of inhalers dispensed to children and their out-of-pocket costs. The former was calculated both per child and per 1000 children with asthma. The latter were calculated as costs for albuterol inhalers in each month for each child.
Like other studies, they found that the out-of-pocket costs for children with cost-sharing increases were larger. They went up $6.11 per month for children with increased cost-sharing versus only $0.36 for children who did not experience the policy change.
As with other studies as well, those who experienced increased cost-sharing also saw their albuterol inhaler use decrease over time. But in this case, a similar decrease was also seen in the control group. There were no significant differences in albuterol use between those exposed to cost-sharing increases and those not exposed to such increases. In other words, it does not appear in this study that the increased cost-sharing from the CFC ban led to decreased use of albuterol in children.
There are a number of reasons these results may differ from prior work. It's possible that the increase of $6 may not have been high enough to cause a difference, and the larger increase in other studies led to more of an effect. It's possible that parents may be willing to skip albuterol themselves, but not for their kids. But it's also possible that the use of control group allowed them to differentiate between changes due to secular trends as opposed to those due to policy changes.
Of course, none of this excuses the increase in price for a medication that has been generic for a long, long time. Many in the health policy community were upset to see pharmaceutical companies and others profiting off of the CFC ban, and making patients pay more. Any increases in cost sharing add a financial burden to families. Moreover, we still don't know how these price increases affect children without insurance, who may be at even more risk.
But just because a study fits our prior beliefs about the way the world works doesn't mean that we shouldn't continue to refine our methods and seek better and more comprehensive findings. This latest research may not be as sexy or make as much of a splash as prior work, but the researchers should be commended for continuing to look for truth.