Trends in Use of Ambulatory Surgery Centers for Cataract Surgery in the United States, 2001-2014

Abstract

Importance: Cataract surgery is commonly performed at ambulatory surgery centers (ASCs) and hospital outpatient departments (HOPDs). These venues differ in many ways, including surgical efficiency, patient throughput, patient safety, and costs per surgery.

Objective: To determine trends in use of ASCs and HOPDs for cataract surgery from 2001 to 2014 and factors affecting the site of surgery.

Design, setting, and participants: This retrospective longitudinal cohort analysis involved individuals 40 years and older who underwent cataract surgery between January 2001 and December 2014 from a nationwide US managed care network. Data were analyzed from February 2016 to February 2017.

Main outcomes and measures: We identified all enrollees who underwent cataract surgery and determined whether the surgery was performed at an ASC or HOPD. We calculated the proportion of surgeries performed at each site each year from 2001 to 2014. Multivariable logistic regression identified characteristics of enrollees who had cataract surgery at an ASC vs a HOPD. We also assessed geographic variation in the proportion of cataract surgeries performed at ASCs in 306 communities throughout the United States.

Results: Of the 369 320 enrollees included in this study, 208 319 (56.4%) were female, and the mean (SD) age was 66.3 (10.4) years. All enrollees underwent cataract surgery (531 325 surgeries) from 2001 to 2014. Of these, 237 046 (64.2%) underwent cataract surgery at an ASC. The proportion of cataract surgeries performed at ASCs increased from 43.6% in 2001 to 73.0% in 2014. Compared with enrollees with incomes less than $40 000, those with incomes greater than $100 000 were 20% more likely to undergo cataract surgery at an ASC (odds ratio, 1.20; 95% CI, 1.12-1.29). Enrollees with better overall health were no more likely to undergo cataract surgery at an ASC (odds ratio, 1.00; 95% CI, 0.99-1.00) than at an HOPD. Enrollees who lived in communities without certificate of need laws were more than twice as likely to have surgery at an ASC (odds ratio, 2.49; 95% CI, 2.35-2.63). The proportion of cataract surgeries performed at ASCs from 2012 to 2014 varied considerably, from 1.6% in La Crosse, Wisconsin, to 98.8% in Pueblo, Colorado.

Conclusions and relevance: We observed a large shift in the site of cataract surgery from HOPDs to ASCs from 2001 to 2014. Future research is needed to assess the effect of this transition in site of surgical care on patient access to surgery, surgical outcomes, patient safety, and societal costs.

Figure 1.. Proportion of Different Types of Ocular Surgeries Performed at an Ambulatory Surgery Center (ASC) Each Year from 2001 to 2014

Figure 2.. Geographic Variation in the Change in Site of Surgery from 2004-2006 to 2012-2014

Map showing the increase or decrease in proportion of cataract surgeries performed at ambulatory surgery centers from 2004-2006 to 2012-2014 by hospital referral region. Hospital referral regions with fewer than 20 patients undergoing cataract surgery in either 2004-2006 or 2012-2014 are reported as “insufficient data” (n = 42).

Figure 3.. Factors Associated With Undergoing Cataract Surgery at an Ambulatory Surgery Center

Multivariable logistic regression model identifying factors associated with undergoing cataract surgery at an ambulatory surgery center (ASC) rather than a hospital outpatient department (HOPD). The error bars indicate 95% CIs. CON indicates certificate of need law; HRR, hospital referral region; OR, odds ratio.