Research Studies

The studies featured here present recent findings about patient safety and quality of care in the ASC setting. Please see the full text for each study to review the methodology and conclusions in greater detail.


Returns to specialization: Evidence from the outpatient surgery market

Journal of Health Economics
Published: January 2018
Finding: Patients experienced a reduction in adverse events following surgery in ASCs relative to HOPDs for the 10 most common procedures (by ASC volume). A reduction in post-procedure adverse events was observed for both low- and high-risk patients.

Inpatient Versus Outpatient Hip and Knee Arthroplasty: Which Has Higher Patient Satisfaction?

The Journal of Arthroplasty
Published: July 2018
Finding: Although satisfaction was high in both outpatient and inpatient groups, when differences were present, patients favored outpatient surgery in the ambulatory surgery center.

Spine Surgery in the Ambulatory Surgery Center Setting: Value-Based Advancement or Safety Liability?

Published: March 2018
Finding: Following a comprehensive review of clinical studies of cervical and lumbar surgeries in ASCs available at the time, the authors conclude that evidence for the safety and utility of multiple outpatient spine procedures is growing and providers, payers, hospitals and patients all stand to benefit if greater investments are made in ASCs for spine surgery.

Competition in Outpatient Procedure Markets

Medical Care
Published: January 2019
Finding: Competition from ASCs benefits consumers through lower prices for outpatient procedures.

Long-term Risk of Colorectal Cancer and Related Deaths After a Colonoscopy With Normal Findings

JAMA Internal Medicine
Published: December 2018
Finding: A colonoscopy with normal findings in average-risk patients appears to be associated with a lower risk of colorectal cancer deaths and overall, proximal, distal, early-stage and advanced-stage colorectal cancer for more than 12 years compared with no screening.

The Safety of Hand and Upper-Extremity Surgical Procedures at a Freestanding Ambulatory Surgery Center: A Review of 28,737 Cases

The Journal of Bone and Joint Surgery
Published: April 2016
Finding: A retrospective review of 28,000+ cases found an overall low (0.20%) rate of adverse events (defined as serious complications leading to patient harm or additional treatment).

Is Outpatient Unicompartmental Knee Arthroplasty Safe to Perform at an Ambulatory Surgery Center? A Comparative Study of Early Post-Operative Complications

The Journal of Arthroplasty
Published: March 2018
Finding: A review of 569 outpatient unicompartmental knee arthroplasties performed 2012 to 2016 (288 ASC, 281 HOPD) revealed no difference in overall complication rate between the two settings.

Outcomes of Surgeries Performed in Physician Offices Compared With Ambulatory Surgery Centers and Hospital Outpatient Departments in Florida

Health Services Insights
Published: April 2017
Finding: Examining a sample of 88 outpatient procedures using a 2008–2012 private claims insurance database, researchers found significantly higher 7- and 30-day hospital admission rates following procedures in HOPDs vs. ASCs and physician offices.

7-day risk adjusted readmission | ASC: 0.82%, PO: 1.57%, HOPD: 1.71%

30-day risk adjusted readmission | ASC: 2.03%, PO: 2.72%, HOPD: 2.98%

Comparing Quality at an Ambulatory Surgery Center and a Hospital-Based Facility: Preliminary Findings

Otolaryngology–Head and Neck Surgery
Published: September 2009
Finding: Study looks at 486 cases performed in either an ASC or hospital-based facility and examines performance at both settings against five quality measures (safety, patient centeredness, timeliness, efficiency and equitability). ASCs performed at least equal to the hospital-based facility in all categories, including significant outperformance in safety, timeliness and cost efficiency.

Safety | ASC: 0 unexpected safety events in 275 cases, HBF: 9 events in 211 cases

Timeliness | ASC: 77% cases finished within scheduled time, HBF: 38% cases within scheduled time

Cost efficiency | Total charges 12–23% less at ASCs

Ambulatory surgery centers and outpatient urologic surgery among Medicare beneficiaries

Published: July 2014
Finding: Study examines Medicare outpatient urologic surgeries conducted 2001–2010 to see whether introducing an ASC to a market affects utilization and quality. Introducing an ASC was found to lower rates of outpatient urologic surgery in the higher-cost hospital setting with no increase in overall outpatient surgery growth or post-procedure hospital admission/mortality.

Outpatient total shoulder arthroplasty in an ambulatory surgery center is a safe alternative to inpatient total shoulder arthroplasty in a hospital: a matched cohort study

The Journal of Shoulder and Elbow Surgery
Published: February 2017
Finding: Comparing two samples (30 patients matched for age/comorbidity) of patients undergoing total shoulder arthroplasty at an ASC and an inpatient hospital, there was no significant difference in 90-day episode-of-care complication rates such as hospital admission/readmission.

Prevalence of Malignant Hyperthermia Diagnosis in New York State Ambulatory Surgery Center Discharge Records 2002 to 2011

Anesthesia & Analgesia
Published: February 2016
Finding: Looked at New York State ambulatory surgery discharge records 2002–2011 for ICD-9-CM code 995.86 (indicates malignant hyperthermia due to anesthesia). Rate of MH found to be 0.18 per 100,000 discharges, less than hospital rate (1 per 100,000) and national rate (1.3 per 100,000).

The outpatient total hip arthroplasty

The Bone & Joint Journal
Published: January 2018
Finding: Looking at 1,472 total hip arthroplasties at an ASC between 2013 and 2016, there was a 2.2% incidence of medical or surgical complication. However, the presence of a patient comorbidity was not associated with these complications (though it was associated w/increased risk of overnight observation).

Hand Surgery in the Ambulatory Surgery Center

Orthopedic Clinics
Published: January 2018
Finding: 65% of hand surgeons report doing most of their surgery at an ASC, and in 2006, 49% of carpal tunnel release procedures were done in ASCs (up from 16% in 1996). Use of ASCs for hand surgery is more cost-effective and efficient than an inpatient facility, with a low (0.2%–2.5%) complication rate.