Study Results on Anesthesia in Screening Colonoscopy

By Arushi Khurana, Sudhanshu Bansal and Sumeet Vashishta

27 June 2018

Practical Analytic Approaches to Healthcare Challenges

The U.S. Preventive Services Task Force recommends colorectal cancer screening for men and women aged 50–75.[i] For colorectal cancer (CRC) screening, colonoscopy has been accepted as the most effective method, with the adenoma detection rate (ADR) remaining one of the most important measures of a quality colonoscopy. Factors shown to affect adenoma and polyp detection rates (PDR) include: use of sedation along with other factors like adequacy of bowel preparation, cecal intubation rate, withdrawal time, image enhancements, and the performing endoscopist.[ii]

Traditionally, conscious (moderate) sedation (CS) using midazolam and an opioid has been used in screening colonoscopies. Until recent Medicare reimbursement changes, for most colonoscopy procedures CS has been considered an inherent part of the procedure, not to be reported and billed separately except for the situation when moderate sedation is provided by a second physician in a facility setting. However over the past decade, newer anesthesia options have become available, and based on a nationwide survey distributed in 2004 to the members of the American College of Gastroenterology, it was found that approximately one quarter of patients now undergo deep sedation with propofol (propofol sedation (PS)).[iii] Although Propofol sedation (PS) has led to detection of more advanced polyps, a retrospective analysis of 699 consecutive patients who underwent inpatient screening colonoscopies at one academic inpatient centre found no significant difference between ADR or location of detected adenomas between the CS and PS groups.2

An upward trend in separate anesthesia by anesthesiologist for screening colonoscopy was found in those with higher comorbidity according to a study conducted on National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database.3 To get an insight into how frequently separate anesthesia services are used in screening colonoscopy, and the associated comorbidities of the patient, we performed an analysis on Commercial plan members aged 50-75 years using a MedInsight data for year 2012. We identified the number of comorbidities the patient had, using diagnosis codes for the conditions used in a similar study.[iv] A comorbidity is assigned only when the member had at least two claims 30 days apart with the corresponding diagnosis code in the two years preceding colonoscopy.

A total of 25,055 screening colonoscopies were performed in the year 2012 with the following characteristics.


Separate anesthesia was given in 3,465 (13.83%) of screening colonoscopies with a breakdown by comorbidity count and gender as given below:


Out of all screening colonoscopies performed under separate anesthesia (3,465) a staggering 62.11% (2,152) had no associated comorbidities and the additional costs for anesthesia services alone in such cases amounted to $ 796,134.

Although separate anesthesia for screening colonoscopies does not improve the ADR and most of the times has not been covered by the insurance plan, it is associated with increased patient satisfaction and reduced pain levels. As a result it has been increasingly used for screening colonoscopy. The Centers for Medicare and Medicaid Services, as a provision of the Affordable Care Act revised the definition of “colorectal cancer screening tests” beginning January 1, 2017 to include anesthesia that is separately furnished in conjunction with screening colonoscopies.[i] It will be interesting to look at the utilization and financial impact of this ruling on commercial and Medicare payers in the near future.

[i] United States Preventive Services Task Force. Recommendations for colorectal cancer screening, 2008. Available at:

[ii] Nakshabendi R, Berry AC, Munoz JC, John BK. Choice of sedation and its impact on adenoma detection rate in screening colonoscopies. Annals of Gastroenterology : Quarterly Publication of the Hellenic Society of Gastroenterology. 2016;29(1):50-55. Available at:

[iii] Khiani VS, Soulos P, Gancayco J, Gross CP. Anesthesiologist Involvement in Screening Colonoscopy: Temporal Trends and Cost Implications in the Medicare Population. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2012;10(1):58-64.e1. doi:10.1016/j.cgh.2011.07.005. Available at:

[iv] Comorbidity Measures for Use with Administrative Data Author(s): Anne Elixhauser, Claudia Steiner, D. Robert Harris and Rosanna M. Coffey Source: Medical Care, Vol. 36, No. 1 (Jan., 1998), pp. 8-27.

[v] Federal Register, The daily Journal of the United States Government. Medicare Program; Revisions to Payment Policies Under the Physician Fee Schedule Clinical Laboratory Fee Schedule, Access to Identifiable Data for the Center for Medicare and Medicaid Innovation Models & Other Revisions to Part B for CY 2015. Available at:

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