1001 Potrero Ave
San Francisco, CA 94110
Dr. Day is an associate professor of medicine at UCSF, Director of Clinical Gastroenterology at the Zuckerburg San Francisco General Hospital (ZSFG) and the Associate Chief Medical Officer for Specialty Care and Diagnostics at ZSFG. His research interests center on organizational design and development of efficiency models for health care system delivery to vulnerable patient populations. Specifically, his research explores the delivery of healthcare through the endoscopy center. He is currently working on developing key innovations that can be implemented at the ZSFG endoscopy center that focus on maximizing staff and physician efficiency, improving patient access to endoscopic care, and strengthening patient satisfaction. His research has spanned projects that have examined the quality of outpatient GI consultation notes, improving patient access though implementing a set of discharge criteria after endoscopy, studying the informed consent process in endoscopy education classes and improving endoscopy center operational efficiency using time and motion studies and simulation modeling.
Education and Training
Degree or Training
University of California, San Francisco
University of California, San Francisco
Recent Articles (41)
Alsayid M, Singh MH, Issaka R, Laleau V, Day L, Lee J, Allison J, Somsouk M. Yield of Colonoscopy After a Positive Result From a Fecal Immunochemical Test OC-Light. Clin Gastroenterol Hepatol. 2018 Apr 13.
Infection control during GI endoscopy. Gastrointest Endosc. 2018 Mar 21.
Selvig D, Sewell JL, Tuot DS, Day LW. Gastroenterologist and primary care perspectives on a post-endoscopy discharge policy: impact on clinic wait times, provider satisfaction and provider workload. BMC Health Serv Res. 2018 01 10; 18(1):16.
Issaka RB, Singh MH, Rachocki C, Day LW, Horton C, Somsouk M. Missed Opportunities in Colorectal Cancer Prevention in Patients With Inadequate Bowel Preparations. Clin Gastroenterol Hepatol. 2018 Jan 09.
Baumgardner JM, Sewell JL, Day LW. Assessment of quality indicators among nurse practitioners performing upper endoscopy. Endosc Int Open. 2017 Sep; 5(9):E818-E824.
Kouanda AM, Somsouk M, Sewell JL, Day LW. Urgent colonoscopy in patients with lower GI bleeding: a systematic review and meta-analysis. Gastrointest Endosc. 2017 Jul; 86(1):107-117.e1.
Lee A, Aditi A, Bhat YM, Binmoeller KF, Hamerski C, Sendino O, Kane S, Cello JP, Day LW, Mohamadnejad M, Muthusamy VR, Watson R, Klapman JB, Komanduri S, Wani S, Shah JN. Endoscopic ultrasound-guided biliary access versus precut papillotomy in patients with failed biliary cannulation: a retrospective study. Endoscopy. 2017 Feb; 49(2):146-153.
Issaka RB, Singh MH, Oshima SM, Laleau VJ, Rachocki CD, Chen EH, Day LW, Sarkar U, Somsouk M. Inadequate Utilization of Diagnostic Colonoscopy Following Abnormal FIT Results in an Integrated Safety-Net System. Am J Gastroenterol. 2017 Feb; 112(2):375-382.
Hassid BG, Day LW, Awad MA, Sewell JL, Osterberg EC, Breyer BN. Using Search Engine Query Data to Explore the Epidemiology of Common Gastrointestinal Symptoms. Dig Dis Sci. 2017 03; 62(3):588-592.
Kidambi TD, Lee R, Terdiman JP, Day L. Successful implementation of Lynch syndrome screening in a safety net institution. J Community Genet. 2016 Jul; 7(3):255-60.
Diversity in gastroenterology in the United States: Where are we now? Where should we go? Gastrointest Endosc. 2016 Apr; 83(4):679-83.
Chang JT, Sewell JL, Day LW. Prevalence and predictors of patient no-shows to outpatient endoscopic procedures scheduled with anesthesia. BMC Gastroenterol. 2015 Sep 30; 15:123.
Day LW, Belson D. Studying and Incorporating Efficiency into Gastrointestinal Endoscopy Centers. Gastroenterol Res Pract. 2015; 2015:764153.
Day LW, Nazareth M, Sewell JL, Williams JL, Lieberman DA. Practice variation in PEG tube placement: trends and predictors among providers in the United States. Gastrointest Endosc. 2015 Jul; 82(1):37-45.
Day LW, Velayos F. Colorectal cancer screening and surveillance in the elderly: updates and controversies. Gut Liver. 2015 Mar; 9(2):143-51.
Day LW. Nonphysician Performance of Endoscopy. Gastroenterol Hepatol (N Y). 2015 Mar; 11(3):190-2.
Sewell JL, Telischak KS, Day LW, Kirschner N, Weissman A. Preconsultation exchange in the United States: use, awareness, and attitudes. Am J Manag Care. 2014 Dec; 20(12):e564-72.
Tuot DS, Sewell JL, Day L, Leeds K, Chen AH. Increasing access to specialty care: patient discharges from a gastroenterology clinic. Am J Manag Care. 2014 Oct; 20(10):812-9.
Day LW, Velayos F. Colorectal cancer of the elderly. Curr Treat Options Gastroenterol. 2014 Sep; 12(3):269-82.
Day LW, Belson D, Dessouky M, Hawkins C, Hogan M. Optimizing efficiency and operations at a California safety-net endoscopy center: a modeling and simulation approach. Gastrointest Endosc. 2014 Nov; 80(5):762-73.
Gupta S, Sussman DA, Doubeni CA, Anderson DS, Day L, Deshpande AR, Elmunzer BJ, Laiyemo AO, Mendez J, Somsouk M, Allison J, Bhuket T, Geng Z, Green BB, Itzkowitz SH, Martinez ME. Challenges and possible solutions to colorectal cancer screening for the underserved. J Natl Cancer Inst. 2014 Apr; 106(4):dju032.
Day LW, Siao D, Inadomi JM, Somsouk M. Non-physician performance of lower and upper endoscopy: a systematic review and meta-analysis. Endoscopy. 2014 May; 46(5):401-10.
Day LW, Lin L, Somsouk M. Adverse events in older patients undergoing ERCP: a systematic review and meta-analysis. Endosc Int Open. 2014 Mar; 2(1):E28-36.
Siao D, Sewell JL, Day LW. Assessment of delivery methods used in the informed consent process at a safety-net hospital. Gastrointest Endosc. 2014 Jul; 80(1):61-8.
Day LW, Velayos F. Colorectal cancer and the elderly. Clin Geriatr Med. 2014 Feb; 30(1):117-31.
Guidelines for safety in the gastrointestinal endoscopy unit. Gastrointest Endosc. 2014 Mar; 79(3):363-72.
Day LW, Lin L, Somsouk M. Adverse events in older patients undergoing ERCP: a systematic review and meta-analysis. Endoscopy International Open. 2014; 1(2):E28-E36.
Sewell JL, Somsouk M, Shah SC, Day LW. Commentary: Towards an effective and safe treatment of small intestine bacterial overgrowth - Authors' reply. Aliment Pharmacol Ther. 2013 Dec; 38(11-12):1411.
Day LW, Bhuket T, Allison J. FIT testing: an overview. Curr Gastroenterol Rep. 2013 Nov; 15(11):357.
Shah SC, Day LW, Somsouk M, Sewell JL. Meta-analysis: antibiotic therapy for small intestinal bacterial overgrowth. Aliment Pharmacol Ther. 2013 Oct; 38(8):925-34.
Sewell JL, Day LW, Tuot DS, Alvarez R, Yu A, Chen AH. A brief, low-cost intervention improves the quality of ambulatory gastroenterology consultation notes. Am J Med. 2013 Aug; 126(8):732-8.
Day LW, Bhuket T, Inadomi JM, Yee HF. Diversity of endoscopy center operations and practice variation across California's safety-net hospital system: a statewide survey. BMC Res Notes. 2013 Jun 15; 6:233.
Day LW, Michelle N, Sewell JL. Open Journal of Gastroenterology. Patient preferences and factors related to the pre-procedure process at a large, urban county hospital. 2013; 3:5-11.
Siao D, Thoeni R, Grenert JP, Day LW. A rare presentation of abdominal pain: idiopathic mesenteric phlebosclerosis. Am J Gastroenterol. 2012 Nov; 107(11):1759-60.
Day LW, Kwon A, Inadomi JM, Walter LC, Somsouk M. Adverse events in older patients undergoing colonoscopy: a systematic review and meta-analysis. Gastrointest Endosc. 2011 Oct; 74(4):885-96.
Day LW, Cello JP, Somsouk M, Inadomi JM. Prevalence of gastric cancer versus colorectal cancer in Asians with a positive fecal occult blood test. Indian J Gastroenterol. 2011 Sep; 30(5):209-16.
Day LW, Walter LC, Velayos F. Colorectal cancer screening and surveillance in the elderly patient. Am J Gastroenterol. 2011 Jul; 106(7):1197-206;quiz 1207.
Day LW, Espey DK, Madden E, Segal M, Terdiman JP. Screening prevalence and incidence of colorectal cancer among American Indian/Alaskan natives in the Indian Health Service. Dig Dis Sci. 2011 Jul; 56(7):2104-13.
Day LW, Cello JP, Madden E, Segal M. Prospective assessment of inpatient gastrointestinal consultation requests in an academic teaching hospital. Am J Gastroenterol. 2010 Mar; 105(3):484-9.
Cello JP, Day LW. Idiopathic AIDS enteropathy and treatment of gastrointestinal opportunistic pathogens. Gastroenterology. 2009 May; 136(6):1952-65.
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