Scientists often use randomized controlled trials (RCT) to examine whether certain treatments have a causal effect on patient outcomes. For social scientists, however, conducting an RCT is more difficult. Nevertheless, there have been a number of health policy trials.
In a recent NEJM paper, Newhouse and Normand (2017) review some of these trials. A summary is below:
Trials that vary prices paid by patients:
- RAND Health Insurance Experiment. This experiment randomized people between full coverage (i.e., no cost sharing) and various cost sharing insurance schemes. The study found that for the average patient, reduced cost sharing did not affect health outcomes, but health did improve for patients with more severe initial health limitations or those that were low income. The study also found that paying providers using prepaid (i.e., capitation) plans compared to fee-for-service physicians reduced hospitalizations).
- Oregon Health Insurance Experiment. In 2008, Oregon initiated a limited expansion of its Medicaid program for low-income adults through a lottery drawing of approximately 30,000 names from a waiting list of almost 90,000 persons. Selected adults won the opportunity to apply for Medicaid and to enroll if they met eligibility requirements. Comparing outcomes of lottery “winners” and “losers”, the authors found that emergency department use increased among lottery winners and overall healthcare utilization also incrased.
- Post–Myocardial Infarction Free Rx Event and Economic Evaluation (MI FREEE). Study made drugs free after acute myocardial infarction. The group in the free drug arm had 4-6% higher adherence and fewer major vascular events and revascularization.
Trials that vary reimbursement.
- RAND Health Insurance Experiment. This experiment also randomized people between traditional fee-for-service practices and an HMO where physicians were salaried employees and the HMO received a flat per-member, per-month payment. Their study found that patients in the HMO had fewer hospitalizations compared to those in FFS practices.
- Randomization for treatment of LDL cholesterol (LDL-C) . Physicians in the incentives arm were eligible to receive bonus payments when their patients met LDL-C goals and in the control arm no incentative payments were made. The physician incentives did lead to a reduction in LDL-C.
The article also provides a summary of some of the key decisions researchers need to make when designing a health policy trial. These decisions include:
- What Inducement, if Any, Should Be Offered to Participants?
- How Many Sites Should There Be?
- How Long Should the Experiment Run?
- How Should Individual Patients or Families Be Assigned to Treatments?
- To What Degree Should Groups of Special Interest Be Oversampled?
- What Baseline Physiological Characteristics, if Any, Should Be Measured?
- Newhouse, Joseph P., and Sharon-Lise T. Normand. “Health Policy Trials.” New England Journal of Medicine 376, no. 22 (2017): 2160-2167.