Formulary Decision Support and Medication Adherence

Medication non-adherence is supposedly a very large problem, although I suspect the numbers sometimes quoted are not fully accurate.  A new paper from BioMed looks at whether e-prescribing coupled with formulary clinical decision support can increase medication adherence, at least in regard to its prescription filling aspect.   (BioMed Paper)   The basic design was the use of e-prescribing in a large New Jersey health plan.  Patient drug claims from practices using e-prescribing and those not using it were compared.  The e-prescribing system included a formulary decision support module, which clued physicians in on prescribing drugs from preferred tiers, where copays are usually later.  Initially the formulary decision support was non-interruptive, just a display of alternatives, later it was changed to interruptive, which more intrusively encouraged physicians to use prescribed drugs only.  The claims were for two common classes of drugs, angiotension receptor blockers, for hypertension, and inhaled steroids, for asthma.

The use of e-prescribing and the availability of non-interruptive and interruptive formulary decision support all appeared to increase prescribing of preferred drugs.  The greatest change was among high-prescribing doctors with interruptive formulary decision support, whose use of brands rose from 61% to 78%.  The preferred brands, however, on average had to me what were pretty minor copay differences, so getting more preferred drug use didn’t provide a huge out-of-pocket expense benefit to patients.  This was reflected in the non-significant distinction in medication possession ratios between the groups.  The ultimate conclusion from this study would seem to be that cost is the predominant factor in the prescription filling behavior of patients.  Lower copays encourage more prescription filling, which is the first step, but not the only important step, in medication adherence.  E-prescribing and formulary decision support can help ensure use of lower cost-sharing drugs, but the copay difference needs to be large enough to be meaningful to patients.