Results Summary

What was the research about?

A trip to the emergency room, or ER, can be stressful. Patients sometimes call 911 for health problems that can be safely treated outside the ER. In other countries, having paramedics safely treat patients at home has reduced ER trips.

In this study, the research team tested a program to help people with urgent health problems avoid unnecessary ER visits called the Acute Community Care Program, or ACCP. In ACCP, specially trained paramedics treated patients with urgent health problems at home rather than taking them to the ER.

Patients who received ACCP care lived in the greater Boston area and called the healthcare system between 6 p.m. and 2 a.m. A nurse determined whether they had an emergency health problem, such as crushing chest pain. If the problem seemed like an emergency, the nurse told patients to go to an ER. If not, the nurse sent paramedics to the patient’s home. Doctors spoke with paramedics while they were treating the patient.

What were the results?

The study results were mixed. Compared with patients who went to the ER, patients who received ACCP care were

  • No more or less likely to visit the ER 1–15 days after their original health problem
  • Less likely to go the ER 16–90 days after their urgent health problem
  • More likely to have a hospital stay in the 90 days after their health problem

Who was in the study?

The study included medical records from 4,212 healthcare visits for patients who were part of a large healthcare system in Massachusetts. All patients were eligible for both Medicare and Medicaid. The average patient age was 68, and 70 percent were women.

What did the research team do?

The research team looked at medical records of patients who received ACCP care and patients who went to the ER. For each record of a patient in ACCP, the research team looked at the records of three patients who went to the ER who were similar based on the patients’ age, gender, level of disability, and the types of health problems. The team compared how many ER visits and hospital stays patients had in the 90 days after their urgent health problem.

Paramedics and doctors helped design the study and provided feedback throughout the study.

What were the limits of the study?

ACCP served patients in the greater Boston area. Results may differ in other locations. The health records didn’t include enough data for the team to see if patients had similar health problems, which may have affected the study’s results.

Future studies could test other programs that use paramedics to help people avoid unnecessary ER visits. They could look at these programs using more in-depth data.

How can people use the results?

Health plans and healthcare systems can use these results when considering ways to help people with urgent health problems avoid unnecessary ER visits.

Final Research Report

View this project's final research report.

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. Those comments and responses included the following:

  • Reviewers asked that the report be revised so that emergency department (ED) visits were not described as “unnecessary,” which typically reflects the perception of the healthcare system and may reflect a lack of viable alternatives as seen by participants. The researchers observed that the program they developed was one option offered as a choice to participants, rather than imposed on participants. The researchers also reviewed the instances where they used the word “unnecessary” in the report and stated that in most cases they provided appropriate context for the word.
  • Reviewers noted that an important consideration for the study was  that participants receiving Acute Community Care Program (ACCP) services not only had fewer follow-up ED visits than participants seen initially in the ED, but that the ACCP service also took the place of the initial ED visit. The researchers stated that they used analytic methods to account for the lack of randomization between the ACCP and ED groups, which would not allow them to make conclusions regarding ACCP replacing an ED visit. The reviewers also pointed out that because the offering of ACCP services were from 6 pm to 2 am but that researchers measured time to subsequent ED visit or hospitalization in days, it is not clear whether the ED or hospitalization event actually occurred much later in the ACCP group since the time of day was not provided. The researchers stated that time of encounter was not reported for the ACCP visit or subsequent ED or hospitalization occurrence. Therefore, the researchers could not say how many hours after the ACCP encounter a patient might have an ED visit or be hospitalized. They acknowledged this limitation in their report, but also pointed out that any bias produced because of not having this information was against the ACCP intervention, leading to more conservative conclusions regarding the effectiveness of that intervention.
  • The reviewers said that it would be good to know which conditions appear to be well treated by the ACCP tested in this study and which conditions led to emergency department visits and hospitalizations. The researchers explained that paramedics made notes about participants’ major conditions but did not use a coding system to describe them, and the researchers were not able to find any pattern for the kinds of conditions that had better or worse outcomes. The researchers suggested that as the ACCP becomes more established, data may be collected in a more systematic way.
  • The reviewers asked how the researchers involved participants in the study as stakeholders. The researchers said they never considered involving the acutely ill individuals who received care as stakeholders in the study. Given concerns about burdening participants, the researchers did not expect that clinicians would have allowed access to acutely ill participants, and it would not have been possible to predict in advance who would develop urgent health problems and need help from paramedics. Two employees of the Disability Policy Consortium in Massachusetts served as stakeholders representing the community.

Conflict of Interest Disclosures

Project Information

Lisa I. Iezzoni, MD
Massachusetts General Hospital
Acute Community Care to Avoid Unnecessary Emergency Department Visits^

Key Dates

September 2015
February 2020

Study Registration Information

^This project was previously titled: Providing Emergency Services at Home to Patients Who Receive Medicare and Medicaid


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Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
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 25, 2023