The Effect of Informative Letters on the Prescription and Receipt of Schedule II Controlled Substances

A letter to outlier prescribers of schedule II controlled substances explaining that their prescribing behavior is highly unlike their peers.

2014-09-11

2015-09-11

The primary outcome of the study is the effect of the letters on the prescribing of schedule II controlled substances over the 3 months following the initial sending of the letters. Prescribing is defined as the total “days supply” of schedule II controlled substances attributed to the prescriber, expressed in “30-day equivalents” i.e. divided by 30.

We consider additional outcomes as well. Through these additional analyses, we hope to understand the totality of the effects of the letters. The secondary analysis for prescribers includes explorations of effect heterogeneity, quantile treatment effects, substitution toward other substances, and peer effects. We also conduct analyses looking at a cohort of patients who were treated by the prescribers prior to the sending of the letters. We will assign these patients to treatment and control groups based on whether their attributed prescriber was a treatment or control prescriber and study the total receipt of controlled substances by patients, heterogeneity in treatment effects, substitution toward other substances, and health outcomes.

An analysis was conducted to identify outlier prescribers of Schedule II controlled substances in the Medicare Part D. This analysis identified a group of prescribers, and they were then randomly allocated to a treatment or a control group.

Randomization done by computer (in Stata)

The prescriber (e.g. physician, nurse, physician assistant, etc.)

No

Approximately 1500 prescribers

Approximately 1500 prescribers

Approximately 750 providers in the control arm and 750 providers in the treatment arm

We constructed a sample of outlier prescribers that replicated the method used in the study but was built from a more limited dataset. Using these prescribers we estimated that at a significance level of 5% and a power of 80%, we could detect a change in the number of schedule II prescription drug events of 136.9 (baseline mean level: 1,556.7; standard deviation: 1,231.2; effect as a share of baseline mean: 8.8%) and a change in the dollar value of schedule II prescriptions of $34,069 (baseline mean level: $217,204; standard deviation: $239,759; effect as a share of baseline mean: 15.7%). Since we will have access to richer data with better control variables, we believe that these estimates are conservative.

Prespecification of Analyses for Schedule II Controlled Substances Letter Campaign

Inappropriate prescribing is a rising threat to the health of Medicare beneficiaries and a drain on Medicare’s finances. In this study we used a randomized controlled trial approach to evaluate a low-cost, light-touch intervention aimed at reducing the inappropriate provision of Schedule II controlled substances in the Medicare Part D program. Potential overprescribers were sent a letter explaining that their practice patterns were highly unlike those of their peers. Using rich administrative data, we were unable to detect an effect of these letters on prescribing. We describe ongoing efforts to build on this null result with alternative interventions. Learning about the potential of light-touch interventions, both effective and ineffective, will help produce a better toolkit for policy makers to improve the value and safety of health care.

Sacarny, Adam, David Yokum, Amy Finkelstein, and Shantanu Agrawal. "Medicare Letters To Curb Overprescribing Of Controlled Substances Had No Detectable Effect On Providers." Health Affairs. 2016; 35(3); 471-479. doi:10.1377/hlthaff.2015.1025

http://content.healthaffairs.org/content/35/3/471