Case Report on a Rare Malignancy: Anorectal Melanoma

Introduction: Melanoma of the rectum is an extremely rare disease. The median survival rate is 2-5 years. Current treatment for this aggressive cancer is resection if possible and consider adjuvant or neoadjuvant radiotherapy;immunotherapy in nonresectable cases. Given the rapid spread of disease due to its submucosal growth and metastasis pattern, there is low success rates with treatments. Case Description/Methods: An 84-year-old male presented to the emergency department with an acute COVID-19 infection. The patient was also found to have gram-negative septicemia on blood cultures, so a CT abdomen/pelvis was performed (Figure 1a). The CT showed rectal wall thickening. A flexible sigmoidoscopy was planned for a future outpatient visit after recovering from his acute infection. The patient, however, developed an acute onset of dyspnea and had a high probability V/Q scan while in the hospital. He was started on anticoagulation, and shortly after starting therapy the patient developed bright red rectal bleeding. Due to the new onset of rectal bleeding it was decided to expedite the sigmoidoscopy. The sigmoidoscopy was performed in the hospital showing an ulcerated partially black pigmented non- obstructing medium-sized mass that was partially circumferential involving one-third of the lumen (Figure 1b). A biopsy of the lesion was taken using cold-forceps. The pathology stained positive for S100 consistent with melanoma. The diagnosis of anorectal melanoma was made, and colorectal surgery was consulted. The patient was deemed not to be a surgical candidate secondary to age and active COVID-19 infection. Oncology was consulted, and it was decided to start the patient on radiation and immunotherapy with a PD-1 inhibitor. Discussion(s): The symptoms of anorectal melanoma can be subtle and in this case report completely asymptomatic. Symptoms to be aware of are rectal bleeding and tenesmus. Diagnosing melanoma on sigmoidoscopy can be challenging as most tumors are not pigmented. Biopsies should be taken and sent for immunohistochemical staining for S100, if positive the patient should have a PET scan. Treatment choices for the tumor are based on staging. In a resectable tumor sphincter-saving local excision with radiotherapy to the site of the tumor and the pericolic and inguinal lymphatics is recommended. For unresectable tumors or tumors with distant metastasis, immunotherapy with PD-1 inhibitors (nivolumab and ipilimumab) is an emerging treatment choice.

Marginal Artery of Drummond Pseudoaneurysm Masquerading as Fistulous Tract Resulting in Recurrent Lower Gastrointestinal Bleeding

Introduction: The mortality rate of patients hospitalized with a lower gastrointestinal bleed has been reported at 1.1% in the United States from 2005 to 2014. Pseudoaneurysms, typically associated with pancreatitis, have been described in case reports as a rare condition with a small subset presenting as gastrointestinal bleeding. Our study describes a rare case of recurrent lower gastrointestinal bleeding diagnosed as a pseudoaneurysm by endoscopy and angiography. Case Description/Methods: A 38-year-old male presented to our facility from a long-term care facility with hematochezia and blood clots per gastrostomy-jejunostomy. He had recently been hospitalized for severe coronavirus disease 2019 with a complicated hospital course in the intensive care unit including necrotizing pancreatitis with an abdominal drain, multiple secondary infections, tracheostomy, and percutaneous endoscopic gastrostomy-jejunostomy. On previous hospitalization, he was found to have a small pseudoaneurysm of the gastroduodenal artery and received embolization of the gastroduodenal and gastroepiploic arteries at that time. During transport to our hospital, he was noted to have tachycardia, hypotension requiring norepinephrine, and was transfused one unit of red blood cells. Hemoglobin at this time was 7.5 g/dl after transfusion. Esophagogastroduodenoscopy was completed and showed a gastrojejunostomy tube in the expected location but was noted to be tight to the mucosa, which was pale in appearance. Flexible sigmoidoscopy revealed localized areas of edematous and erythematous mucosa with some associated oozing throughout the sigmoid colon. Repeat evaluation was completed one week later due to recurrent hematochezia. Colonoscopy was performed with identification of an apparent fistulous tract in the sigmoid colon located at 35 cm. Computed tomography angiography localized a pseudoaneurysm arising from the marginal artery of Drummond just proximal to its anastomosis with the ascending branch of the left colic artery and was successfully embolized. Discussion(s): Pseudoaneurysms, such as the one described in this case, have been shown to be associated with pancreatitis and can result if a pseudocyst involves adjacent vasculature. Gastrointestinal bleeding is a rare presentation of this condition. However, this case highlights the importance of repeat colonoscopy and angiography in the setting of a lower gastrointestinal bleed of unknown etiology.

Application of Neoaortoiliac System For Contained Rupture of Mycotic Infrarenal Aortic Aneurysm

Funding: None. Synopsis: 61-year-old male who initially presented to an outside facility with streptococcal pneumoniae meningitis and bacteremia. Of note, he had history of COVID-19 pneumonia a month prior. On hospital day 15, he reported sudden onset lower back pain prompting imaging which demonstrated a contained rupture of an infrarenal aortic aneurysm that had significantly evolved in comparison to admission imaging where his infrarenal aorta had the largest dimension measuring 2.9cm. We present the successful application of neoaortoiliac system (NAIS). Method(s): Proceeding with midline laparotomy we encountered dense adhesive disease due to his history of surgery for colon cancer. After adhesiolysis, we exposed the aorta and aneurysm with severe surrounding inflammatory changes. 20cm of femoral vein was harvested, reversed, and joined for a span of 4cm using an Endo GIA 45mm vascular load to create our neoaorta. Proximal and distal clamp zones were developed. Upon entering the aneurysm, a foul smell was encountered, revealing that the noxious process had destroyed the posterior wall of the aorta and paraspinal tissues. Our neoaorta was anastomosed in end-to-end fashion to the infrarenal aorta and subsequently to the common iliac arteries. Flow was initially restored to the hypogastric arteries and then the external iliac arteries. The retroperitoneum was closed over our repair and covered with omentum. Result(s): On post-operative day 2, he had hematochezia;intraoperatively, the IMA was noted to be 1mm in size, though had brisk back-bleeding and was ultimately ligated. A flexible sigmoidoscopy revealed ischemic sloughing of the sigmoid colon near his previous anastomosis from his colon cancer resection though no transmural necrosis. He remains on high-dose ceftriaxone to complete a 6-week course and metronidazole for 10 days due to his sigmoid mucosal ischemia per infectious disease recommendations. He is now post-operative day 10 and remains in the ICU. Conclusion(s): Mycotic aortic aneurysms constitute 1-1.8% of aortic aneurysms. The standard of treatment is aggressive debridement of involved aortic wall and periaortic tissue, in-situ or extra-anatomic reconstruction, coverage with an omental flap and long-term antibiotic therapy. NAIS is resistant to infection and aneurysmal dilation, however, is a time-consuming procedure with a mean completion time of 8 hours. Dorweiler et al. demonstrated that vascular reconstruction with femoral vein in infected aortoiliofemoral fields has a mortality of 9-10% with negligible rate of late complications (graft stenosis, thrombosis, and dilation) and that venous morbidity after femoral vein harvest is well tolerated. Clagett et al. demonstrated that NAIS fashioned from greater saphenous vein had a failure rate requiring intervention of 64% compared to 0% for those constructed with deep femoral vein. Lastly, it is important to note that our patient was previously COVID-19 positive. This case demonstrates that the sequela of COVID-19 may have been a significant factor in our patient's pathophysiology. As we continue to learn about the effects of COVID-19 on vascular pathology, we must keep a large repertoire of operative techniques at hand in order to treat complex presentations of vascular emergencies. [Formula presented] [Formula presented] [Formula presented] Institution: Orlando Health, Orlando, FLCopyright © 2022

Colorectal cancer screen-up-to-date: 10-year prevalence in a regional safety-net health system

Introduction: Colorectal cancer (CRC) screening is an effective secondary prevention method with an increased probability of diagnosing CRC at an earlier stage, and a consequent improvement in survival post-treatment. This is especially true for individuals who undergo guideline recommended screening at appropriate intervals. Studies have reported a consistent rise in long-term trends of guideline-adherent screen-up-to-date (SUTD) rates among predominantly White and insured individuals. Here we use longitudinal data from 2011-2020 and report 10-year prevalence and correlates of CRC SUTD among patients in a safety-net health system. Method(s): All patients aged 50-74 years who had a primary care encounter in any of the 12 community clinics in a large county safety-net health system were included. An individual was considered to be SUTD if he/she had a stool test during the calendar year, flexible sigmoidoscopy in the past 5 years, or colonoscopy in the past 10 years. To obtain a population health estimate (and not only examine frequencies), we included in the denominator patients with a primary care visit in the past 3 years. Multivariable generalized estimating equations (GEE) model was used to examine the association of SUTD status with time-varying demographic and clinical characteristics over the 10-year period. Result(s): Our analytical cohort had 50,647 patients in 2011, of which 40.9% (20,708) patients were SUTD. Annual rates of SUTD were largely unchanged until 2019, when the prevalence increased to 46.8% after initiation of a population health outreach mailed FIT program. The SUTD rate fell to the baseline level of 40.8% in 2020 after the pandemic-induced suspension of the mailed FIT program. Multivariable GEE model demonstrated that older patients, females, and Hispanics had higher odds of being SUTD compared to younger patients, males, and non-Hispanics, respectively. Additionally, patients who had prior interaction with the healthcare system (had prior stool tests or prior primary care encounters) had higher odds of being SUTD than those with no prior experience with the healthcare system (no prior stool tests or no prior primary care encounters). Conclusion(s): This study establishes contemporary evidence about the 10-year prevalence and correlates of CRC SUTD status among patients in a safety-net health system. Prevalence remained constant for most of the decade, except in 2019, when a population-based mailed FIT outreach program was implemented to complement usual visit-based screening. Despite the disruptions caused by the COVID-19 pandemic, screening rates in 2020 did not drop below pre-2019 levels (~40%), though the prior increases due to the mailed FIT program were lost. We believe that effective implementation of broad population-based, screening outreach efforts are instrumental in improving and sustaining CRC SUTD rates in safety-net health systems, and can consequently help to decrease CRC incidence and related mortality.

DIEULAFOY LESION CAUSING LOWER GI BLEEDING: A CASE OF COVID-19 CRITICAL ILLNESS PROMPTING UNUSUAL PRESENTATION OF A MORE RARE CONDITION

SESSION TITLE: COVID-19 Case Report Posters 1 SESSION TYPE: Case Report Posters PRESENTED ON: 10/17/2022 12:15 pm - 01:15 pm INTRODUCTION: Dieulafoy lesions are abnormally dilated submucosal vessels remain uncommon cause of upper gastrointestinal bleeding, accounting for approximately 1.5% of all GI bleeds [1]. Although the exact etiology remains unknown, multiple co-morbid conditions have been attributed to this condition, including heart diseases, hypertension, chronic kidney disease, diabetes, or excessive alcohol use [2].In our case, it was identified as a cause of lower GI bleed in a critically ill Covid patient. CASE PRESENTATION: A 49-year-old male with a history of diabetes, internal hemorrhoids, and diverticulosis was admitted to the hospital due to hypoxic respiratory failure from COVID pneumonia with characteristic CT findings of bilateral ground-glass opacification. On admission, the patient was afebrile, normotensive, tachypneic with a respiratory rate of 34.The physical examination was unremarkable except for coarse crackles in upper and middle lung zones. We treated patient with Dexamethasone and Remdesivir. His hypoxia deteriorated, and he was eventually intubated. On admission patient hemoglobin was within normal range. During the patient's hospital course, he had a significant drop in hemoglobin, requiring multiple blood transfusions. Blood clots were found on perianal examination. Flexible sigmoidoscopy revealed blood in the rectosigmoid colon. A visible vessel without apparent ulcer was seen in the rectum, which was actively oozing blood. It was determined to be a Dieulafoy lesion. The affected area was injected with epinephrine for hemostasis, and subsequently, hemostatic clips were placed. After the procedure patient did not have any repeat episodes of hematochezia or drop in hemoglobin. DISCUSSION: Dieulafoy lesions are an uncommon cause of GI bleeding and are usually present in the upper gastrointestinal tract. Furthermore, they caused hemodynamically significant bleeding from the lower gastrointestinal tract in our case. Dieulafoy lesions can be asymptomatic or may bleed intermittently to cause severe hemodynamic compromise. They may be missed on endoscopy due to the small size and intermittent bleeding [2]. In up to 9-40% of the cases, these lesions tend to rebleed. Therefore the patients need close monitoring [3]. In our case, after the intervention with the clips, the patient's bleeding stopped, and he had no further blood loss from the lesion. CONCLUSIONS: Dieulafoy's lesion is an infrequent cause of gastrointestinal bleeding, and it is challenging to diagnose [3]. It is a rare cause of GI bleeding, and even in those instances, it is found chiefly in upper GI bleed cases but can also be the cause of lower GI bleeding. Knowing that GI bleeding in Covid patients leads to worse outcomes, it is prudent to account for rare causes of GI bleed during the work-up. Reference #1: Van Zanten SV, Bartelsman J, Schipper M, Tytgat G. Recurrent massive haematemesis from Dieulafoy vascular malformations–a review of 101 cases. Gut. 1986;27(2):213. Reference #2: Shin HJ, Ju JS, Kim KD, et al. Risk factors for Dieulafoy lesions in the upper gastrointestinal tract. Clinical Endoscopy. 2015;48(3):228. Reference #3: Baettig B, Haecki W, Lammer F, Jost R. Dieulafoy's disease: endoscopic treatment and follow up. Gut. 1993;34(10):1418-1421. DISCLOSURES: No relevant relationships by Swe Swe Hlaing No relevant relationships by Joyann Kroser No relevant relationships by Hui Chong Lau No relevant relationships by Sze Jia Ng No relevant relationships by Subha Saeed No relevant relationships by Muhammad Moiz Tahir

Method of Instruction Delivery Does Not Affect Quality of Bowel Preparation for Pediatric Colonoscopy

Introduction: Pediatric colonoscopy is a routine procedure used to diagnose and treat gastrointestinal conditions. Effective delivery of bowel preparation (BP) instructions is important to achieve optimal cleanout results and can occur in a variety of methods including in-person, written pamphlet, or video. Inadequate preparation has been shown to increase the duration of colonoscopy, potentially increasing the procedural risk and the inability to complete the procedure, which leads to the need for repeat procedures associated with increased costs, risks, and psychological hardships. Thus, several studies have looked at optimal medication regimens for adequate BP and different delivery methods of BP instructions for adult colonoscopies, finding that more BP education results in greater patient comprehension, thereby improving BP scores. Objective(s): However, there is limited information on which delivery method of BP instruction yields optimal cleanouts, specifically for pediatric patients undergoing colonoscopy. The aim of this quality improvement study was to determine if the quality of BP is affected by the method of instruction delivery. Method(s): Our centre's delivery method of BP instructions had historically been in-person by a physician or nurse case manager (NCM), but in 2019 we developed an online video for families to watch instead. From 2019 to 2021, patients aged 0-18 years and their families received either in-person or video instructions (both along with a written pamphlet to take home) on BP prior to colonoscopy. In 2020, due to the COVID-19 pandemic, patients began receiving instructions over the phone, recorded as 'in-person' along with a mailed-out pamphlet. In March 2020, due to staff shortages, some families were only receiving the written pamphlet, so this third modality of instructions were also included in the study. We excluded inpatient BPs, flexible sigmoidoscopies and repeat colonoscopies. Outpatient BP consisted of pico-salax with dosing based on the patient's weight, the day before the procedure. The Ottawa Bowel Preparation Quality Scale was used to score the BP, with a cut-off score <7 as adequate cleanout at the time of colonoscopy. Patient age, indication for scope, method of delivery and time to procedure were captured. Video and pamphlet only groups were combined into one alternative instruction group due to small numbers for statistical analysis. Primary outcome was the differences in BP scores between the in-person and alternative instruction groups. Result(s): Of the 136 patients (mean age 11.51y (SD 4.53)), 81 (60%) received in-person BP instructions (46 from a physician (62.2%) and 28 from a NCM (37.8%) n=74), 25 (18%) received video instructions, and 30 (22%) received pamphlet only. The median time from BP instruction to the scope procedure was 30 days (IQR 14, 49;range 1-116 days), but only captured prior to onset of COVID pandemic. BP adequacy was achieved in 81.2% of patients (Table 1). There were no significant differences in BP adequacy (76.8% vs. 83.6%, p=0.333) or mean (SD) total BP score between in-person and other (video/pamphlet) methods (5.33 (3.0) vs. 5.33 (2.89), p=0.997), respectively. Age was not a significant predictor for BP scores (p>0.094), but indication for scope did predict total BP score, albeit irrespective of delivery method. Patients who underwent colonoscopy for an indication of IBD had higher total BP scores than those without (M=6.81, SD=2.66 vs. M=5.06, 2.93, p=0.005) and patients who had polyp had lower BP scores than those without (M=2.58, SD=2.07 vs (M=5.59, SD=2.89, p=0.001). Conclusion(s): In conclusion, method of BP instruction delivery for pediatric patients undergoing colonoscopy does not impact quality of BP. Further studies are required to explore the role of parental factors such as education, socioeconomic status, or primary language on BP quality as well as the role of waiting times for endoscopy on the retention of information.

AUTOMATED FOLLOW-UP USING A PATIENT-GUIDED COMPLICATION TRACKING SYSTEM (PACTS): AN UPDATE ON PROGRESS

Background: In recent years, there has been an increase in automated interventions in medicine. The COVID-19 outbreak has further fueled this rise. In response to the pandemic, Healthcare systems have developed a multitude of technological strategies for case identification and contact tracing. It is in this evolving digital landscape, that a PAtient-guided Complication Tracking System (PACTS) was launched. PACTS allows clinics to track complications using the Short Message Service (SMS). This program also offers opportunities to augment medical services and support patients having complications. Before PACTS can be widely implemented in clinics, research needs to be conducted to investigate its potential as a complication tracking software. Aims: To assess the outcomes of an automated follow-up program implemented at St. Paul's Hospital in Vancouver, BC. Methods: A prospective study was designed to contact outpatients one-week post-procedure using PACTS. This program was delivered in two phases. Stage 1 ran from November 2019-March 2020. During this pilot stage, patients having a colonoscopy or gastroscopy were asked to participate in the study. Stage 2 ran from August 2020-August 2021. For this phase, patients having a colonoscopy, gastroscopy or flexible sigmoidoscopy were automatically enrolled in the study. An independent t-test was completed to assess response rate differences between stages. SMS responses were recorded and patients having unplanned events were contacted by phone to categorize complications. Adverse events (AE) were defined as side-effects requiring telehealth follow-up or emergency room visitation. Severe adverse events (SAE) were classified as complications requiring admission to hospital (>24 hrs). Results: SMS prompts were sent to 6975 patients and the overall mean response rate was 89%. The mean response rates from Stages 1 and 2 were 92% and 88% respectively. The independent t-test revealed a statistically significant difference in response rates between phases, two-sample t(174) = 4.56, p = 9.58 x 10-6. 498 (8%) of SMS respondents reported having unplanned events. Of these patients, 372 (75%) were reached by phone and 257 (69%) were confirmed to have had a side effect. 65 of these complications were AEs and of these, 3 cases were SAEs. The most common AEs were abdominal pain (37%), bleeding (35%), nausea and vomiting (14%). Conclusions: The high response rates achieved during this study provide further evidence for the use of automated follow-up systems in medicine. This study also demonstrates the potential of PACTS as a complication tracking software. Future research should devise strategies to optimize the collection of complication data using an SMS-based service. (Table Presented).

A PEER-LED PROGRAMME TO IMPROVE ACCESS TO ENDOSCOPY TRAINING

Introduction Endoscopy training has been significantly impacted by the COVID-19 pandemic. The Joint Advisory Group on GI Endoscopy issued guidance for the recovery of endoscopy training. This provided us with an opportunity to improve endoscopy training with a peer-led programme. Methods The programme involved a group of trainees using the EndoVault® endoscopy system to scrutinise endoscopy lists to establish their suitability for training. A senior trainee was tasked to allocate the endoscopy lists based on trainee availability and current training objectives. The allocations were made on a 2-weekly cycle. We analysed the number of procedures over a 4-month period (1st March-30th June) for 2019, 2020 and 2021. Trainee satisfaction for 2021 was assessed pre- and post-intervention using a Likert scale based survey. Results There was a significant increase in the number of training procedures performed by trainees, comparing 2019 (pre-pandemic) and 2021 (post-intervention) - 21.7% vs. 59.8%, p<0.0001. The greatest increase was access to training in colonoscopy (297%), with also increased access for gastroscopy (270%) and flexible sigmoidoscopy (242%), represented as the change in the proportion of available training procedures performed by trainees comparing 2019 to 2021. Furthermore, trainees performed more independent procedures. Table 1 summarises the number of endoscopic procedures identified and performed by trainees during 2019, 2020 and 2021 (with∗Denotes p<0.001 relative to 2019 data and +denotes p<0.001 relative to 2020 data for comparator proportions represented). The survey showed an improvement in satisfaction of trainees' access to endoscopy with 100% of all responding trainees (n=16) being satisfied (25% pre-intervention). 87.5% of all trainees advised the programme helped them to meet their endoscopy training objectives. Conclusions This programme, devised by trainees for trainees, had a significant improvement in access to endoscopy training. This was further reflected in the results of the satisfaction survey. This programme could easily be applied at other hospital trusts as a model of training delivery.

EARLY INTESTINAL ULTRASOUND PREDICTS ENDOSCOPIC RESPONSE ON ANTI-INFLAMMATORY TREATMENT AND SHOWS DRUG-SPECIFIC RESPONSE TO BIOLOGICALS AND TOFACITINIB IN ULCERATIVE COLITIS

Introduction Objective evaluation of treatment response is the gold standard in ulcerative colitis (UC). In this setting, intestinal ultrasound (IUS) is a non-invasive alternative to endoscopy. Recent studies showed change in IUS parameters after treatment initiation but studies with an endoscopic reference standard are scarce. The aim of this study was to evaluate early change of IUS parameters and determine cut-off values for endoscopic endpoints in UC patients starting anti-inflammatory treatment. Methods In this longitudinal prospective study consecutive patients with moderate-severe UC (baseline endoscopic Mayo score (EMS)≥2) starting an anti-inflammatory treatment were included. Clinical scores, biochemical parameters and IUS parameters were collected at baseline, after 2 (T1), 6 (T2) and 8-26 weeks (T3) around time of the second sigmoidoscopy/colonoscopy. Bowel wall thickness (BWT), Colour Doppler signal (CDS), haustrations, inflammatory fat and wall layer stratification were measured as previously established1. Endoscopic remission (ER) and mucosal healing (MH) were evaluated in the sigmoid and defined as EMS=0 and EMS≤1, respectively. The ultrasonographist and endoscopist were blinded for the outcomes of endoscopy and IUS, respectively. Results 51 consecutive patients were included (Table 1) of whom 31 underwent a second endoscopy. Two additional patients underwent colectomy and were considered non-responders. 18 patients did not undergo second endoscopy due to the COVID-19 pandemic (n=2), refusal (n=5), loss to follow-up (n=1) or treatment escalation because of clinical deterioration confirmed by IUS and biomarkers before second endoscopy was performed (n=10). BWT was significantly lower from T2 onwards in patients reaching MH (p=0.026) and ER (p=0.002) at T3 (Fig 1). A significant decrease in BWT was already visible at T1 in patients receiving infliximab (median DBWT T0-T1: -26% [-43% - -6%], p=0.001) or tofacitinib (median ∆BWT T0-T1: -33% [-46% - -5%], p=0.001) but not in patients treated with vedolizumab (median ∆BWT T0-T1: -14% [-43% - 5%], p=0.11). Most accurate BWT cut-off values at T3 to determine MH and ER were 3.52 mm (AUROC: 0.95, 95% CI: 0.86-1.00, p<0.0001, sens:91%, spec:91%) and 2.98 mm (AUROC: 0.94, 95% CI: 0.85-1.00, p=0.001, sens:87%, spec:100%), respectively. At T2, BWT per 1 mm increase and CDS were inversely associated with MH (BWT: OR: 0.48 (0.24-0.96, p=0.038);CDS: OR 0.16 (0.03-0.83), p=0.028) and ER (BWT: OR: 0.30 (0.11-0.76), p=0.01). Conclusion BWT and CDS 6 weeks after start of treatment could predict MH and ER. In addition, treatment response at IUS is drug-specific. Furthermore, we have provided accurate BWT cut-off values for endoscopic outcomes. In a point-of-care setting, (early) treatment evaluation with IUS could guide treatment decision in UC in order to optimize treatment response. 1. Bots et al. JCC 2021

ENDOSCOPY IN THE COVID-19 ERA: IMPACT ON DISPARITIES IN AMBULATORY ENDOSCOPIC CARE

Background: The COVID-19 public health emergency (PHE) led to the initial cessation of non-emergent outpatient procedures, resulting in derailment of routine care and screening. After the early phase of PHE, pre-procedural measures such as routine COVID-19 testing were instituted to allow safe resumption of outpatient endoscopy. However, these measures may also cause unintended barriers to access care, particularly for vulnerable groups. We aimed to evaluate patient and clinical factors associated with completion of endoscopic outpatient procedures (EOP) at an ambulatory endoscopy center (AEC) before and during the pandemic. Methods: This was a retrospective cohort study of all completed EOP at a tertiary AEC during the period prior to the PHE (4/1/2019-02/28/2020) and after re-opening of the unit during the COVID-19 pandemic (05/15/2020-12/31/2020). All routine, nonadvanced procedures (upper endoscopy, colonoscopy, sigmoidoscopy, push enteroscopy) were included. Variables evaluated included self-identified race/ethnicity, age, sex, median income by home zip code, insurance coverage and procedural indication (screening/surveillance or diagnostic). Univariate analyses were performed using Fisher-exact, Mann-Whitney U or student's t-test. Multivariable analyses were conducted using logistic regression. Results: In total, 23,086 EOP were included, with 12,161 (52.7%) performed pre-PHE. Compared to pre-pandemic, the pandemic EOP cohort was more likely younger, White, and undergoing a diagnostic procedure (all p<0.05). Conversely, the pandemic cohort had a smaller proportion of Non-Hispanic Black (NHB) and Latino/a/x patients compared to the pre-PHE cohort (all p<0.05). On multivariable analysis, White race (OR 1.163;[1.058-1.268]) and diagnostic procedures (OR 1.281;[1.154-1.409]) were independently associated with EOP completion during the pandemic, although there was significant effect modification between these two predictors (interactive term OR 0.807;[0.669-0.945]) (Table 2). On separate multivariable models constructed, Latino/a/x (OR 0.869;[0.731-1.000]) and NHB (OR 0.600;[0.350- 0.849]) patients were independently associated with lower odds of undergoing EOP during the pandemic compared to pre-PHE. Conclusions: Vulnerable groups including NHB, Latino/a/x, and older patients were independently associated with lower odds of EOP completion during the pandemic, particularly for screening procedures. COVID-19 specific measures, such as routine pre-EOP testing, may add barriers to care that disproportionately affect these vulnerable groups. Efforts must be made to ensure equitable access to endoscopic care, including routine screening procedures. Special attention should be paid to vulnerable groups when instituting policies that may affect procedural access, particularly given the risk of an ongoing PHE, to avoid widening existing disparities. (Table Presented)

Impact of the Pandemic COVID-19 on Digestive Endoscopic Activity: Experience of a Moroccan Service

OBJECTIVES: In Morocco, in order to prepare health facilities for the upcoming influx of COVID-19 patients, it was necessary to minimize non-COVID-19 related activities, which led to a significant reduction of non-urgent procedures. The aim of the study was to describe the impact of the COVID-19 pandemic on the digestive endoscopic activity in our department by comparing it to the previous year. Study design: This was a retrospective study. METHODS: We performed a retrospective study, comparing endoscopic procedures performed (excluding emergencies) in both 2019 and 2020, especially the periods from March 20 to June 30 (lockdown period). Statistical analysis was performed by SPSS 21.0 software. RESULTS: 5018 endoscopy procedures were performed in 2019 and 2020, but only 1869 performed in 2020. For the lockdown period, a large decrease in the number of patients undergoing endoscopy was seen in 2020 compared with 2019 (179 vs 863). Gastroscopy, colonoscopy, and rectosigmoidoscopy volumes experienced a 59%, 53%, and 67% reduction, respectively. A reduction of 50% in the number of echo-endoscopy was also seen, especially during the lockdown period 11 versus 21 in 2019 (p = 0.006), whereas the number of ERCPs remained relatively unchanged, with 22 during the lockdown period versus 29 in 2019 (p < 0.001). We also compared the different endoscopy procedures performed during the post-lockdown period compared to the same period in 2019. CONCLUSION: The COVID-19 pandemic had a significant impact on endoscopy services, its staff and especially on patients following the reduction and limitation of endoscopy indications and procedures.

Early intestinal ultrasound predicts endoscopic response to anti-inflammatory treatment and shows drug-specific response to biologicals and tofacitinib in Ulcerative Colitis

Background: Objective evaluation of treatment response is the gold standard in ulcerative colitis (UC). In this setting, intestinal ultrasound (IUS) is a non-invasive alternative to endoscopy. Recent studies showed change in IUS parameters after treatment initiation but studies with an endoscopic reference standard are scarce. The aim of this study was to evaluate early change of IUS parameters and determine cut-off values for endoscopic endpoints in UC patients starting anti-inflammatory treatment. Methods: In this longitudinal prospective study consecutive patients with moderate-severe UC (baseline endoscopic Mayo score (EMS)≥2) starting an anti-inflammatory treatment were included. Clinical scores, biochemical parameters and IUS parameters were collected at baseline, after 2 (T1), 6 (T2) and 8-26 weeks (T3) around time of the second sigmoidoscopy/colonoscopy. IUS parameters were measured as previously established1. Endoscopic remission (ER) and mucosal healing (MH) were evaluated in the sigmoid and defined as EMS=0 and EMS≤1, respectively. The ultrasonographist and endoscopist were blinded for the outcomes of endoscopy and IUS, respectively. Results: 51 consecutive patients were included (Table 1) of whom 31 underwent a second endoscopy (MH: n=15 (45%), ER: n=9 (27%)). Two additional patients underwent colectomy and were considered non-responders. 18 patients did not undergo second endoscopy due to the COVID-19 pandemic (n=2), refusal (n=5), loss to follow-up (n=1) or treatment escalation because of clinical deterioration confirmed by IUS and biomarkers before second endoscopy was performed (n=10). Bowel wall thickness (BWT) was significantly lower from T2 onwards in patients reaching MH (p=0.026) and ER (p=0.002) at T3 (Fig 1). A significant decrease in BWT was already visible at T1 in patients receiving infliximab (p=0.001) or tofacitinib (p=0.007), but not in patients treated with vedolizumab (p=0.11) (Fig 2). Most accurate BWT cut-off values at T3 to determine MH and ER were 3.52 mm (AUROC: 0.95, 95% CI: 0.86-1.00, p<0.0001, sens: 91%, spec: 91%) and 2.98 mm (AUROC: 0.94, 95% CI: 0.85-1.00, p=0.001, sens: 87%, spec: 100%), respectively. Other IUS parameters at T3 did not improve association with MH or ER. IUS parameters at T2 that predict MH and ER are demonstrated in Table 2. Conclusion: BWT and Colour Doppler Signal 6 weeks after start of treatment are associated with and could predict MH and ER. In addition, treatment response patterns at IUS are drug-specific. Furthermore, we have provided accurate BWT cut-off values for endoscopic outcomes. In a point-of-care setting, (early) treatment evaluation with IUS could guide treatment decision in UC in order to optimize treatment response.

IMPACT OF THE COVID-19 PANDEMIC ON ENDOSCOPY CANCELLATIONS

Background: The coronavirus disease 19 (COVID-19) pandemic has disrupted healthcare delivery including cancellation of elective endoscopy. Despite the implementation of safety protocols to limit COVID-19 spread in endoscopy units, significant fear of infection remains among patients. We aimed to determine the prevalence of endoscopy cancellations in the COVID-19 era and identify patient characteristics associated with cancellation due to the pandemic. Methods: Medical charts were reviewed for adults who cancelled a scheduled endoscopic procedure from 5/2020-8/2020 at a tertiary care academic center. Inpatient endoscopies were excluded. Reasons for cancellation were categorized as COVID-19 related, non-COVID-19 related, or unclear. COVID-19 related cancellations were further categorized as COVID-19 testing logistics related, COVID-19 fear related, or other. The association of patient characteristics with cancellation of endoscopy due to COVID-19 were assessed using logistic regression. Results: 652 patient charts were reviewed. Median age was 58, with55% female, 61% non-Hispanic white, 11% had IBD, and 16% were immunosuppressed.Procedure types included 120 (18%) upper endoscopies (EGD), 362 (56%) colonoscopies, 93 (14%) EGD/colonoscopies, 20 (3%) sigmoidoscopies, and 57 (9%) advanced endoscopic procedures. 211 (32%) cancellations were due to COVID-19, 384 (59%) were due to non-COVID-19 reasons, and 57 (9%) were undetermined. Among COVID-19 related cancellations, 75 (36%) were COVID-19 testing logistics related, 121 (57%) were COVID-19 fear related, and 15 (7%) were other. On multivariate analysis, the odds of cancellation due to COVID-19 was significantly higher for black patients (OR 2.01, 95% CI 1.05-3.86, p=0.04), while patients undergoing EGD (OR 0.50, 95% CI 0.28-0.89, p=0.02) or advanced endoscopy (OR 0.18, 95% CI 0.07-0.49, p=0.001) had lower odds of cancellation [Table 1]. The odds of cancelling due to COVID-19 testing was significantly higher among black patients (OR 3.12, 95% CI 1.03-9.46, p=0.05), patients with Medi-Cal insurance (OR 2.89, 95% CI 1.21-6.89, p=0.02), and patients undergoing sigmoidoscopy (OR 11.6, 95% CI 1.23-108.5, p=0.03) and diagnostic indications (OR 2.96, 95% CI 1.22-7.21, p=0.02). Patients with older age (≥65) had higher odds of COVID-19 fear related cancellation (OR 0.29, 95% CI 0.10-0.81, p=0.02) [Table 2]. Conclusion: COVID-19 has negatively impacted endoscopy scheduling. Diagnostic or therapeutic procedures are associated with a lower risk of cancellation related to COVID-19. Black race is associated with an increased risk of COVID-19 related cancellation. Specifically, black patients and those with Medi-Cal are at increased risk of cancellation related to COVID-19 testing logistics. Racial and socioeconomic disparities in access to endoscopy may be further amplified by the COVID-19 pandemic and warrant further study.(Table Presented)(Table Presented)

Prevalence Of Covid-19 Among Outpatients Presenting For Non-Urgent Endoscopy In A Large Healthcare Network

Background In Response To The Covid-19 Pandemic And National Professional Gastroenterology Society Guidelines, Ucla Health Implemented System-Wide Policies For Safe Non-Urgent Endoscopy On 4/13/2020. These Policies Included Mandatory Nasopharyngeal Covid-19 Testing 48 Hours Prior To All Outpatient Procedures. We Aimed To Determine The Covid-19 Positive Rate Among Outpatients Presenting For Elective Gastrointestinal (Gi) Procedures And To Characterize Patients Who Tested Positive For Covid-19. Methods Ucla Health Is A Large, Integrated Healthcare System With 5 Outpatient Endoscopy Units Across Southern California. Our Study Cohort Included All Patients Scheduled For One Or More Outpatient Procedures (Colonoscopy, Egd, Sigmoidoscopy, Manometry, Ph Study, Small Bowel Enteroscopy, Manometry, Eus, Ercp) Who Underwent Pre-Procedure Covid-19 Testing From 4/13/2020 To 11/5/2020. We Developed An Electronic Dashboard To Track Procedure Date, Type, And Completion Status, Pre-Procedure Covid-19 Test Results 48 Hours Prior To Procedure, And Post-Procedure Covid-19 Test Results Up To 14 Days After A Procedure. We Queried The Electronic Health Record For Patient Data, Performed Manual Chart Review To Identify Covid-19 Symptoms, And Used Administrative Data To Determine Covid-19 Exposures To Gastroenterology Providers And Staff. Our Primary Outcome Was The Preprocedure Covid-19 Positive Rate. We Also Determined Covid-19 Symptom Prevalence And Cases Of New Covid-19 Positivity Post-Procedure. We Used Univariate And Multivariable Logistic Regression To Determine Factors Associated With A Positive Pre-Procedure Covid-19 Test, Controlling For Age, Sex, Race/Ethnicity, And Bmi. Results The Study Cohort Included 9,645 Patients, Representing 10,056 Total Outpatient Scheduled Gi Procedures (Table 1). The Cumulative Pre-Procedure Positive Rate Was 0.3% (N=28), And The Inconclusive Rate Was <0.1% (N=7, Figure 1). One Patient Had A New Positive Covid-19 Result Post-Procedure (Day 4), Associated With New Cough. There Were No Known Covid-19 Exposures Among Gastroenterology Faculty And Staff. Of Patients With A Preprocedure Positive Covid-19 Result, 13 (46.4%) Were Asymptomatic And 10 (35.7%) Had Symptoms Possibly Consistent With Covid-19 (25% Cough, 14.3% Fevers/Chills, 7.1% Diarrhea, 3.6% Myalgias, 3.6% Dyspnea). No Factors Were Significantly Associated With A Positive Pre-Procedure Covid-19 Result In The Multivariable Model. The Covid-19 Testing Positivity Rate Was 3-13% In Los Angeles County During The Study Period. Discussion Implementation Of Mandatory Covid-19 Testing Before Outpatient Gi Procedures Was Successful, And The Positive Rate Was Low. Common Symptoms Among Patients With A Positive Pre-Procedure Covid-19 Result Were Cough, Fevers, And Chills. Although They Were Not Mandated, Post-Procedure Positive Covid-19 Results Were Rare (Table Presented) Patient Characteristics Overall And By Pre-Procedure Covid-19 Test Result (Figure Presented) Pre-Procedure Covid-19 Testing By Result (Per Month And Overall).

COVID-19 AND THE GUT IN HUMAN OBESITY: OVEREXPRESSION OF SARS-COV-2 RECEPTORS REVEALED BY DEEP SINGLE CELL RNA-SEQ

Introduction: Obesity is a major risk factor for severe coronavirus disease, and clinical evidence now supports the GI tract, in addition to the respiratory system, as a potential route for SARS-CoV-2 infection. Expression of viral entry factors ACE2, TMPRSS2, and CTSL have been detected along the human GI tract including gastric, ileal and colonic mucosa. It is unclear whether obesity confers increased susceptibility to initial SARS-CoV-2 infection, or what gut mechanisms in obesity predispose to vulnerability to SARS-CoV-2. Thus, we aimed to investigate, by single cell RNA-sequencing (scRNA-Seq) of human colonic mucosa, whether patients with obesity may be more susceptible to SARS-CoV-2 infection, by virtue of enhanced expression of SARS-CoV2 entry cofactors followed protein assessment in colon biopsies. Methods: We studied 19 patients: 10 lean (age 33±3y, BMI 23±1kg/m2, 90% female), and 9 with obesity (age 43±3y, BMI 36±1kg/m2, 89% female). Human colonic biopsies from lean (n=4 scRNA-Seq;n=6 validation) and obesity (n=6 scRNASeq;n=3 validation) participants were obtained by sigmoidoscopy. Biopsies were dissociated, and viable cells were FACS-isolated. Chromium-10X Genomics was used for scRNA-Seq library prep, followed by Illumina HiSeq4000 sequencing. COVID-19 entry factors displaying significant differential expression between lean and obesity were then validated for gene, and protein expression in the validation cohort using Illumina TruSeq, and quantitative immunofluorescence confocal microscopy, respectively. Results: The initial dataset analysis revealed sequencing of 59,653 cells, 705 million reads, at 127,000 reads per cell. The human colonic mucosa partitioned into 20 cell subsets (Fig1A,B), and 15 of the 20 clusters displayed detectable expression of at least one of the COVID-19 entry factors: TMPRSS2, CTSL, or ACE2 (Fig1C,D,E). Goblet cell expression of TMPRSS2 was increased 4.6-fold (p<0.05), stromal cell expression of CTSL was increased 1.2-fold (p<0.0001), and ACE2 expression was increased 1.27-fold (p<0.001) in crypt-top (CT) colonocytes of obesity compared to lean controls (Fig2A). Colonic overexpression of TMPRSS2 mRNA (p<0.05) and protein (p<0.05), and CTSL (p<0.05) mRNA, but not ACE2 mRNA, in obesity was further validated in a second validation cohort (Fig2B-F). Conclusions: scRNA-Seq analysis of human colonic epithelium in obesity compared to healthy controls revealed multiple epithelial cell subsets (goblet cell, stromal, and colonocytes) with overexpression of COVID-19 entry factors TMPRSS2, CTSL, and ACE2, confirming the digestive system as a portal for infection by SARS-CoV-2.Furthermore goblet, stromal, and colonocyte-specific overexpression of TMPRSS2, CTSL, and ACE2 in obesity may play a significant role in increased initial susceptibility to COVID-19, and worse disease outcomes in human obesity.(Figure Presented) Single-Cell RNA-Seq Profiling of Human Colonic Epithelium in Obesity. A) t-SNE plot of single-cell RNA-seq profiles of native human colonic epithelial cells, colored by cluster number and identity, listed by largest to smallest population, and annotated by cluster identity, determined by highest ranking gene marker for the colonic cells clustered and profiled between lean and obesity, where dotted blue, red, and green circles represents goblet cells, stromal cells, and CT colonocytes, respectively. B) Proposed cluster identities based on conserved expression of known markers for annotated cell types. Clusters identified displayed expression of at least one of the COVID-19 entry factors: TMPRSS2, CTSL, or ACE2. The average proportion of cells in annotated clusters expressing, C) TMPRSS2, D) CTSL, and E) ACE2 among all studied participants.

Colorectal cancer diagnosed at sigmoidoscopy, is colonoscopy necessary to assess for synchronous cancer?

Introduction The Association of Coloproctology of Great Britain & Ireland (ACGBI) 2017 colorectal cancer (CRC) guidelines reaffirmed the longstanding practice of assessing for synchronous cancer in patients diagnosed with CRC at sigmoidoscopy (f-sig). Ideally by colonoscopy in addition to CT staging of chest, abdomen & pelvis (CT CAP), or alternatively CT colonography (CTC) and CT thorax if complete colonoscopy not possible. In the literature, approximately 3.5% of patients had synchronous CRC. Scheduling colonoscopy may delay treatment and be onerous for patients. Access to prompt colonoscopy can be challenging due to capacity issues, especially in the COVID-19 pandemic era. Methods Data were retrospectively analysed from electronic endoscopy, radiology and pathology records from patients diagnosed with CRC at f-sig and colonoscopy over 11 years (2010-2020 inclusive). Results Analysis 1: 680 patients who had CRC diagnosed at fsig: 230 underwent pre-treatment colonoscopy (33.8%). Interval between f-sig and colonoscopy;mean 17.5 days/ median 15.0 days. Two synchronous cancers identified at colonoscopy;0.9% 1. 57 years old man with primary rectal cancer and synchronous transverse colon cancer - both lesions reported on staging imaging scans. • 69 years old woman with a primary rectal cancer and synchronous sigmoid colon cancer (not seen at f-sig due to poor preparation) - both lesions reported on staging imaging scans. Analysis 2: 796 patients who had CRC diagnosed at colonoscopy: 48/796 have a significant 2nd finding (6.0%) • 24 had synchronous CRC (3.0%)/24 had a significant polyp >20 mm (3.0%) In these 48 cases, if F-sig was performed instead of colon, what would have been the outcome? • Only in one case would a significant lesion be missed. 72 years old man with a primary rectal cancer and a 30 mm ascending colon polyp (not seen on staging CT scan). • In the other 47 cases;staging CT scans pick up lesions or metastases, or lesions are all left sided and would be seen at F-sig, or lesions are all right sided and would not be seen at f-sig, or missed lesion was a benign polyp. Conclusions This is a large analysis of 1476 patients diagnosed with CRC. Of the 796 diagnosed at colonoscopy, 6.0% had a synchronous lesion (48 patients), 3.0% had a synchronous CRC, only 1 patient would have had a missed lesion if they'd had a f-sig alone. Of the 680 patients diagnosed with CRC at f-sig, 230 had a colonoscopy (33.5%), the rest were precluded due to advanced disease/obstruction or weren't fit due to advanced age/co-morbidity. Colonoscopy was undertaken at a median of 15.0 days. The yield of identifying a synchronous cancer at colonoscopy in this cohort is < 1%, in both cases these lesions were reported on staging imaging scans. British Society of Gastroenterology and ACPGBI guidelines from 2019 suggest that in patients who are fit/suitable they should undergo a surveillance colonoscopy at 12 months post CRC diagnosis. Given the capacity issues affecting colonoscopy services in the pandemic era, a proposed pathway for patients diagnosed with CRC at sigmoidoscopy;if staging imaging scans shows resectable CRC without synchronous lesion, is to consider undergoing surgery and to utilise 12-month colonoscopy to clear any adenomas. Alternatively CTC and CT thorax could be utilised though capacity issues may limit this approach. This data supports the consideration of alternative approaches as the likelihood of a synchronous cancer not seen at sigmoidoscopy and staging imaging scan appears to be very low.

Comparison of endoscopic activity before and during the covid pandemic at a tertiary care hospital in South Punjab

Introduction: Coronavirus disease 2019 (COVID-19) has resulted in dramatic changes to health-care delivery. Endoscopic activity has had frequent disruptions during this pandemic. The objective of the study was to see the influence of pandemic over the endoscopic activity. Methods: This retrospective analysis of endoscopic activity was undertaken at Nishtar Hospital Multan. Procedural analysis was done in the three months immediately after covid lockdown (1st April till 30th June 2020) and was compared to a similar period one year back. Results: Five hundred and fifty-four (68.5%) patients underwent endoscopic procedures during the three months of pre-COVID era, while this number reduced to half (n=255, 31.5%) patients during the covid pandemic. Even though the absolute number of Esophagogastroduodenoscopies (EGDs) reduced during the pandemic, patients were more likely to undergo EGDs during the COVID pandemic in contrast to the era before the pandemic (79% versus 66%, p = 0.002). The most common indication for EGD was upper gastrointestinal bleeding (UGIB). The percentage of EGDs done for UGIB rose from almost 60% to 80% during the covid pandemic (p < 0.001). The most common findings were esophageal varices and portal gastropathy (non-significant difference during and before the pandemic). Percentage of ERCPs done for obstructive jaundice doubled during the COVID pandemic (33% versus 65%, p = 0.002).The most common indication for sigmoidoscopy or colonoscopy was lower gastrointestinal bleeding. However, no significant difference was found before and during the covid pandemic (41.7% and 45.8% respectively, p=0.72). Internal hemorrhoids were the most common endoscopic finding. Colon cancer diagnosis reduced from 10% to undetected during the pandemic period. Conclusion: COVID pandemic resulted in considerable reduction in all type of endoscopic procedures. Majority of procedures were done for emergency indications like gastrointestinal bleeding. Rates of cancer detection was significantly reduced.

Reduction in Standard Cancer Screening in 2020 throughout the U.S.

Cancer screening is an important way to reduce the burden of cancer. The COVID-19 pandemic created delays in screening with the potential to increase cancer disparities in the United States (U.S.). Data from the 2014-2020 Behavioral Risk Factor Surveillance System (BRFSS) survey were analyzed to estimate the percentages of adults who reported cancer screening in the last 12 months consistent with the U.S. Preventive Services Task Force (USPSTF) recommendation for cervical (ages 21-65), breast (ages 50-74), and colorectal cancer (ages 50-75) prior to the pandemic. Cancer screening percentages for 2020 (April-December excluding January-March) were compared to screening percentages for 2014-2019 to begin to look at the impact of the COVID-19 pandemic. Screening percentages for 2020 were decreased from those for 2014-2019 including several underserved racial groups. Decreases in mammography and colonoscopy or sigmoidoscopy were higher among American Indian/Alaskan Natives, Hispanics, and multiracial participants, but decreases in pap test were also highest among Hispanics, Whites, Asians, and African-Americans/Blacks. Decreases in mammograms among women ages 40-49 were also seen. As the 2020 comparison is conservative, the 2021 decreases in cancer screening are expected to be much greater and are likely to increase cancer disparities substantially.

Implementation of long-term non-participant reminders for flexible sigmoidoscopy screening.

The clinical effectiveness of screening is highly dependent on uptake. Previous randomised controlled trials suggest that non-participant reminders, which highlight the opportunity to re-book an appointment, can improve participation. The present analysis examines the impact of implementing these reminders within the English Flexible Sigmoidoscopy (FS) Screening Programme, which offers once-only FS screening to adults aged 55-59 years. We assessed the screening status of 26,339 individuals invited for once-only FS screening in England. A total of 10,952 (41.6%) had attended screening, and were subsequently ineligible. The remaining 15,387 had not attended screening, and were selected to receive a reminder, 1-2 years after their invitation. Descriptive statistics were used to assess the increase in uptake and the adenoma detection rate (ADR) of those who self-referred, six months after the delivery of the final reminder. Pearson's Chi-Square was used to compare the ADR between those who attended when invited and those who self-referred. Of the 15,387 adults eligible to receive a reminder, 13,626 (88.6%) were sent a reminder as intended (1,761 were not sent a reminder, due to endoscopy capacity). Of these, 8.0% (n = 1,086) booked and attended an appointment, which equated to a 4.1% increase in uptake from 41.6% at baseline, to 45.7% at follow-up. The ADR was significantly higher for those who self-referred, compared with those who attended when invited (13.3% and 9.5%, respectively; X 2 = 16.138, p = 0.000059). The implementation of non-participant reminders led to a moderate increase in uptake. Implementing non-participant reminders could help mitigate the negative effects of COVID-19 on uptake.