Results Summary

What was the research about?

Medicare Part D is the part of Medicare that covers prescription medicines. People who enroll in Medicare Part D coverage must choose a plan. But choosing among plans can be hard, and people may not always make an informed choice.

In this study, the research team created a decision aid called CHOICE. Decision aids help people choose among healthcare options based on what is most important to them. The CHOICE website gave people personalized information to help them choose a plan.

The research team compared three ways of helping people choose:

  • CHOICE decision aid only. For this group, the CHOICE website showed a list of plans, including each person’s current plan. CHOICE pulled information about each person’s prescriptions from their electronic health records. It then showed each person’s likely spending based on these prescriptions. CHOICE also included a star rating based on quality ratings from consumers.
  • CHOICE decision aid with expert advice. For this group, the website labeled the top three plans as “recommended for you” for each person. The team based these recommendations on plan cost and quality.
  • Publicly available plan information. People in this group received a reminder to enroll in a plan and information on how to do so. They could also use public resources such as the plan finder to review plan options.

What were the results?

Users of CHOICE with expert advice switched plans more often and were happier with the process than people who got only publicly available plan information. People in the CHOICE only and public information groups did not differ in plan switching or happiness with the process. Users of CHOICE both with and without expert advice spent more time choosing a plan than people who got publicly available plan information.

The three groups did not differ in

  • How conflicted they felt about their decision after they enrolled
  • How much they knew about Medicare Part D

Who was in the study?

The study included 928 people ages 66–85 with Medicare who received care from a health system in California. Of these, 80 percent were white, and 8 percent were Asian. The average age was 72, and 50 percent were women. The median household income in the areas where people in the study lived was a little over $113,000.

What did the research team do?

The study took place in Fall 2016 when people were choosing a plan for 2017. After enrolling people in the study, the research team assigned them by chance to one of the three ways to help people pick a plan.

People took surveys at the start and end of the study. The surveys asked

  • Whether people switched plans
  • How happy they were with the choice process
  • How much time they spent choosing a plan
  • How conflicted they felt about their decisions
  • How much they knew about Medicare Part D

Older adults with Medicare, a caregiver, a pharmacist, and medical foundation staff gave input on the CHOICE website. They also helped with recruitment.

What were the limits of the study?

People in the study lived in areas where many people have high incomes. Results may differ for people on Medicare who live in low-income areas.

Future research could study people’s satisfaction with plans chosen using the CHOICE website over the long term.

How can people use the results?

Groups that help people enroll in Medicare could use these results when considering whether to offer a decision aid like CHOICE to help people choose a Part D plan.

Final Research Report

View this project's final research report.

More to Explore...


Using an Online Decision Support Tool to Assist with Medicare Part D Selections
Principal Investigator Mary Bundorf describes her project, which created and tested an online decision support tool to assist patients with their Medicare Part D selections.

Journal Citations

Article Highlight: People who enroll in Medicare Part D, which covers prescription medicines, must choose a plan, but many people struggle to make an informed choice. Researchers on this study created a decision aid to help people choose among the options based on what is most important to them. They then tested whether the decision aid, with or without machine-based, personalized expert recommendations, influenced outcomes for Medicare Part D enrollees. Results published in Health Affairs show that patients who used the decision aid reported increased satisfaction with the process of choosing a prescription drug plan and the amount of time they spent choosing a plan.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented, and the researchers made changes or provided responses. The comments and responses included the following:

  • Reviewers asked for additional information about the selection of 1,185 people in the original study sample from the 29,000 originally eligible for the study. They noted that there were limitations that should be noted in the report regarding the use of passive recruitment strategies that required participants to contact investigators rather than researchers actively recruiting participants. In particular, this recruitment strategy may have led to sampling bias, where the participants were not truly representative of the population. The researchers explained that given their short study enrollment period, they believed this passive enrollment strategy to be the most effective way of achieving an adequate study sample. They also believed that a more active recruitment strategy would not have been feasible.
  • Reviewers repeatedly expressed concern about the study’s lack of generalizability to a wide segment of the Medicare population since patients in all phases of this study were predominantly Caucasian and highly educated. The researchers responded, indicating the demographic characteristics of study participants more prominently in the report. They also expanded their discussion of the potential sampling bias in relation to study generalizability as well as study limitations.
  • Reviewers asked whether the study attempted to assess whether family members assisted participants in using the project’s web-based tool. The researchers said they neither encouraged nor discouraged participants from seeking help in using the website. However, they found in a final survey that 15 percent of participants reported receiving some assistance from family members or friends. There were no significant differences between study arms in the percent of participants receiving such assistance.
  • Reviewers suggested that it would have been interesting to stratify focus group and ethnographic results based on a number of key themes and participant characteristics. The researchers agreed that this would be interesting but explained that they did not link exit survey data with qualitative results. Therefore, the researchers stated that they could not stratify results by patient characteristics because of the way they collected data.

Conflict of Interest Disclosures

Project Information

Mary Bundorf, PhD, MPH, MBA
Stanford University School of Medicine
Creating a Patient-Centered Tool to Help Medicare Beneficiaries Choose Prescription Drug Plans

Key Dates

December 2013
January 2019

Study Registration Information


Has Results
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Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
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Last updated: January 20, 2023