CAHPS Outpatient and Ambulatory Surgery Survey

The CAHPS Outpatient and Ambulatory Surgery Survey (OAS CAHPS) asks adult patients about their experiences receiving care in Medicare-certified hospital outpatient surgery departments (HOPDs) and ambulatory surgery centers (ASCs). The survey asks about patients' experiences with:

  • Preparation for the surgery or procedure
  • Check-in and pre-operative processes
  • Cleanliness of the surgery facility
  • The surgery facility staff
  • Discharge from the facility
  • Preparation for recovering at home

HOPDs and ASCs can use the survey results to improve the services provided to patients and to support consumers in making informed health care choices.

How To Get the CAHPS OAS Survey and Administrative Guidance

To access this survey and supporting documentation for survey administration, please visit CMS's website for the Outpatient and Ambulatory Surgery Survey. No documentation for this survey is available on AHRQ's Web site.

For technical assistance with this survey, contact:

National Implementation of the CAHPS OAS Survey

CMS began voluntary national data collection with the OAS Survey in January 2016. Participation in the voluntary period is open to any interested Medicare-certified HOPDs and ASCs. Through, CMS reports the patient survey results for hospital outpatient departments and ambulatory surgical centers.

Quality Measures from the CAHPS OAS Survey

OAS Survey results are reported for three composite measures and two global items:

Composite Measures

  • About Facilities and Staff
  • Communications About Your Procedure
  • Preparations for Discharge and Recovery

Global Items

  • Overall Rating of Facility
  • Patient's Willingness to Recommend HOPD or ASC to Family or Friends

Development of the CAHPS OAS Survey

The Centers for Medicare & Medicaid Services (CMS) began developing the Outpatient and Ambulatory Surgery Survey in 2012 using the principles and guidelines established by the Agency for Healthcare Research and Quality's (AHRQ) CAHPS program.

Initial instrument development. The goal of the survey development process was to identify and include dimensions of care that patients and other consumers want or need to inform their choice of an HOPD or ASC. This process included:

  • Reviewing surveys submitted as a result of a public call for measures.
  • Reviewing existing literature.
  • Conducting focus groups with patients who had a recent outpatient surgery or procedure.

Refining the instrument. To ensure the usefulness of the draft instrument, the team responsible for its development conducted cognitive interviews with patients to test their understanding and ability to answer the questions and obtained stakeholder input on the draft survey and implementation approach.

Field test. A field test was conducted in the summer of 2014 with 36 facilities (18 HOPDs and 18 ASCs) to test the reliability and validity of the survey items and implementation procedures.  Based on the field test findings, the survey instrument was revised and finalized. The final survey has 37 items.

Mode experiment. In 2015, a mode experiment was conducted to test data collection modes, detect potential nonresponse bias, determine patient characteristics that influence OAS Survey results, and develop models to adjust or control for these characteristics prior to public reporting.

Review by the CAHPS Consortium. AHRQ approved this instrument as a CAHPS survey in February 2015.

Page last reviewed July 2019
Page originally created May 2016
Internet Citation: CAHPS Outpatient and Ambulatory Surgery Survey. Content last reviewed July 2019. Agency for Healthcare Research and Quality, Rockville, MD.
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