Related Experiment Video
Updated: Jul 19, 2026

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
Health plan decision making in the Medicare population: results from a national randomized experiment
L A McCormack1, W L Anderson, J D Uhrig
1RTI International, Research Triangle Park, NC 27709, USA.
Objective:
To examine the effect of providing the Medicare & You handbook on consumers' attitudes and behavior regarding health plan decision making.
Data Source:
A national sample of 3,738 Medicare beneficiaries who were surveyed in late 1999 and early 2000 was employed. Data were collected using a mail survey with telephone follow-up; the response rate was 76 percent.
Study Design:
Medicare beneficiaries were randomly assigned to a control group that received no Medicare-related in formation as part of the study, or to a treatment group that received a copy of the 2000 version of the Medicare & You handbook as part of a national mailing. Half of the treat men t group (the "re-mail" group) received a second copy of the handbook along wit h their mail survey instrument.
Principal Findings:
The control and treatment groups did not differ regarding their level of satisfaction with or confidence in their current choice of health plan according to predicted mean values. Treatment group beneficiaries had a significantly higher propensity to either change or consider changing health plans relative to beneficiaries in the control group. Controlling for other factors, 5 percent of treatment group members switched health insurance plans during the prior month compared to 3 percent of control group members. there were no significant differences in predicted values between the re-mail and no re-mail groups in any of the models. Type of supplemental insurance was also highly related to all three outcomes.
Conclusions:
Findings from this and a prior parallel study suggest th at messages contained in the Medicare & You handbook can have an influence on beneficiaries and the Medicare market . Thus, careful attention should be given to the wording and intent of these messages. This is particularly relevant given the current administration's emphasis on increasing enrollment in Medicare+Choice plans and findings from earlier research reporting that beneficiaries felt the handbook was pressuring them to enroll in managed care.
Related Concept Videos
Group Design
Methods Of Healthcare Delivery System
Managed Care System:
The managed care system is designed to control the cost while maintaining the quality of care. The patient's care from admission to discharge is planned by the primary care provider or the case manager, also known as the gatekeeper. In a managed care system, the number of care providers is limited...
What is an Experiment?
Randomized Experiments
Simple randomization
Simple...
Bioequivalence Experimental Study Designs: Completely Randomized and Randomized Block Designs
Impact of Pharmacokinetic–Pharmacodynamic Models: Regulatory Decisions
