Hospital-based, acute care after ambulatory surgery center discharge.
BACKGROUND
As a measure of quality, ambulatory surgery centers have begun reporting rates of hospital transfer at discharge. This process, however, may underestimate the acute care needs of patients after care. We conducted this study to determine rates and evaluate variation in hospital transfer and hospital-based, acute care within 7 days among patients discharged from ambulatory surgery centers.


METHODS
Using data from the Healthcare Cost and Utilization Project, we identified adult patients who underwent a medical or operative procedure between July 2008 and September 2009 at ambulatory surgery centers in California, Florida, and Nebraska. The primary outcomes were hospital transfer at the time of discharge and hospital-based, acute care (emergency department visits or hospital admissions) within 7-days expressed as the rate per 1,000 discharges. At the ambulatory surgery center level, rates were adjusted for age, sex, and procedure-mix.


RESULTS
We studied 3,821,670 patients treated at 1,295 ambulatory surgery centers. At discharge, the hospital transfer rate was 1.1 per 1,000 discharges (95% confidence interval 1.1-1.1). Among patients discharged home, the hospital-based, acute care rate was 31.8 per 1,000 discharges (95% confidence interval 31.6-32.0). Across ambulatory surgery centers, there was little variation in adjusted hospital transfer rates (median = 1.0/1,000 discharges [25th-75th percentile = 1.0-2.0]), whereas substantial variation existed in adjusted, hospital-based, acute care rates (28.0/1,000 [21.0-39.0]).


CONCLUSIONS
Among adult patients undergoing ambulatory care at surgery centers, hospital transfer at time of discharge from the ambulatory care center is a rare event. In contrast, the rate of need for hospital-based, acute care in the first week afterwards is nearly 30-fold greater, varies across centers, and may be a more meaningful measure for discriminating quality.
Department of Surgery, Boonshoft School of Medicine, Wright State University, Dayton, OH. Electronic address: justin_p_fox@yahoo.com.
Justin P
JP
Fox
Department of Internal Medicine, Robert Wood Johnson Foundation Clinical Scholars Program, Yale School of Medicine, New Haven, CT; Department of Veterans Affairs/VA Connecticut Healthcare System, West Haven, CT.
Anita A
AA
Vashi
Department of Internal Medicine, Robert Wood Johnson Foundation Clinical Scholars Program, Yale School of Medicine, New Haven, CT; Section of General Internal Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, CT; Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, CT.
Joseph S
JS
Ross
Department of Internal Medicine, Robert Wood Johnson Foundation Clinical Scholars Program, Yale School of Medicine, New Haven, CT; Section of General Internal Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, CT; Cancer Outcomes Policy and Effectiveness Research (COPPER) Center, Yale School of Medicine and Yale Comprehensive Cancer Center, New Haven, CT.
Cary P
CP
Gross
D000289:Admitting Department, Hospital / Q000706:statistics & numerical data*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000554:Ambulatory Care Facilities / Q000706:statistics & numerical data*; D000556:Ambulatory Surgical Procedures; D002140:California; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005431:Florida; D006801:Humans; D008297:Male; D008875:Middle Aged; D009329:Nebraska; D017063:Outcome Assessment, Health Care; D010351:Patient Discharge / Q000706:statistics & numerical data*; D010359:Patient Readmission / Q000706:statistics & numerical data; D010360:Patient Transfer / Q000706:statistics & numerical data*; D013997:Time Factors; D055815:Young Adult