Canadian Tertiary Hospital Research Articles

Diagnostic accuracy of an automated classifier for the detection of pleural effusions in patients undergoing lung ultrasound.

Lung ultrasound, the most precise diagnostic tool for pleural effusions, is underutilized due to healthcare providers' limited proficiency. To address this, deep learning models can be trained to recognize pleural effusions. However, current models lack the ability to diagnose effusions in diverse clinical contexts, which presents significant challenges. To develop and validate a deep learning model for detecting pleural effusions in lung ultrasound images, with adaptable performance characteristics tailored to specific clinical scenarios. A retrospective study was conducted at two Canadian tertiary hospitals to evaluate the detection of pleural effusions of varying sizes and complexities using lung ultrasound. A deep learning model incorporating a frame-level convolutional neural network and a clip-level prediction algorithm was developed and validated against expert annotations. The model was evaluated using a holdout dataset of 103 lung ultrasound clips from 46 patients with pleural effusion and 136 clips from 83 patients without effusion. The general model achieved a sensitivity of 0.90 for small-to-large effusions, with a specificity of 0.89. The large effusion model demonstrated a sensitivity of 0.97 for large effusions while maintaining a specificity of 0.90. The trauma model showed high sensitivity to all effusions, including trace (0.91) and small (0.97) effusions. Our research highlights the development of a deep learning model that effectively detects pleural effusions of varying sizes and complexities on lung ultrasound in different clinical settings. This tool has the potential to enhance emergency physicians' ability to quickly and accurately diagnose effusions, particularly in time-sensitive situations.

An anesthesiology-led perioperative outreach service: experience from a Canadian centre and a focused narrative literature review.

Approximately 320 million surgeries occur annually worldwide, increasingly performed on an ageing, comorbid population in whom postoperative complications contribute significantly to mortality. While anesthesiologists have led advances in perioperative care, the optimal structure of the provision of postoperative care has lacked discourse. In this article, we describe the implementation, structure, role, and benefits of an Anesthesiology Perioperative Outreach Service (APOS) at a Canadian tertiary hospital, providing proactive daily review and management of high-risk surgical patients. The APOS involves routine reviews and care on surgical wards, emphasizing collaboration among anesthesiology, internal medicine, surgery, and geriatric medicine teams, with a specific screening pathway to identify patients experiencing myocardial injury after noncardiac surgery. We discuss case vignettes to illustrate common examples of how the APOS enabled early detection and treatment escalation for deteriorating patients and provide a focused narrative literature review. The anesthesiology-led perioperative outreach model described herein could provide an implementable framework for institutions seeking to enhance their quality of postoperative care-particularly among complex, comorbid patients at risk of postoperative morbidity.

Clozapine clinical toolkit optimizes inpatient clozapine monitoring.

Clozapine is the most effective antipsychotic in the management of treatment-resistant schizophrenia; however, its use is challenging due to the risk of severe adverse effects. Despite the risks associated with clozapine, there is no mandatory monitoring in Canada beyond hematologic testing for agranulocytosis surveillance. This study focuses on the development, implementation, and evaluation of a clozapine clinical toolkit (CTK) targeted at optimizing inpatient clozapine use. A comprehensive literature review was conducted to identify clozapine best practices, experts were consulted, and a comprehensive clozapine CTK was developed and implemented at a large Canadian tertiary hospital in December 2018. To evaluate the CTK, a retrospective chart review was conducted to assess for change in guideline-concordant monitoring pre- and post- CTK implementation. Patients were included if they were > 18 years of age and received clozapine during inpatient admission. Results were analyzed using descriptive and inferential statistics. Among the charts reviewed, 185 and 113 admissions met the pre- and post-CTK inclusion criteria, respectively. Staff used the CTK in the care of 96% of clozapine patients post implementation, and its use resulted in improvements in guideline-concordant monitoring for agranulocytosis and myocarditis. Implementation of the clozapine CTK increased the concordance of clozapine monitoring with best practice recommendations. Future research is necessary to assess the impact of the CTK on clinical outcomes and patient satisfaction.

Transition Readiness Assessment Questionnaire: Skill gaps and psychosocial predictors of transition readiness among adolescents and young adults with chronic medical conditions.

Transferring from paediatric to adult care can be challenging. Adolescents and young adults (AYAs) with chronic health conditions need to develop a specific set of skills to ensure lifelong medical follow-up due to the chronicity of their condition. The Transition Readiness Assessment Questionnaire-French version (TRAQ-FR) is a 19-item questionnaire measuring such skills. The aims of the study were to (1) describe participant characteristics and (2) identify constructs related to, and predictors of, having learned domain-specific transition readiness skills. Participants included 216 AYAs aged 14-20 years (M = 15.93; SD = 1.35; 54.1% male) recruited from five outpatient clinics in a Canadian tertiary hospital. AYAs completed the TRAQ-FR, the Pediatric Quality of Life Inventory 4.0 (PedsQL) and a sociodemographic questionnaire. Descriptive, bivariate and binary logistic regression analyses were conducted. Overall, participants reported significantly higher scores on the Talking with Providers, Managing Daily Activities and Managing Medications subscales than on the Appointment Keeping and Tracking Health Issues subscales (F[41075] = 168.970, p < .001). At the item level, median scores (on a 5-point Likert scale) suggest that AYAs had begun practising five of the 19 skills (median scores ≥4; 'Yes, I have started doing this'), while a median score of 1 ('No, I don't know how') was found for one item ('Do you get financial help with school or work?'). At the subscale level, TRAQ-FR skills and skill gaps were related to AYAs' age, sex and PedsQL scores (ps < .05). Older and female AYAs were more likely to have begun practising specific TRAQ-FR subscale skills. Better psychosocial functioning was also related to having learned specific transition readiness skills. AYAs show several gaps in transition readiness. Targeted intervention in transition readiness skill development could take into account AYAs' age, sex and psychosocial functioning for a successful transfer to adult care.

Using network analyses to characterise Australian and Canadian frequent attenders to the emergency department.

To explore and compare the characteristics of frequent attenders to the ED at an Australian and a Canadian tertiary hospitals by utilising a network analysis approach. We conducted a retrospective population-based study using administrative data over the 2018 and 2019 calendar years. Participants were from a tertiary hospital in Melbourne, Australia, and Toronto, Canada. Frequent attenders were defined as patients with four or more visits in 12 months. Characteristics of younger (18-39 years), middle-aged (40-69 years) and older (70 years and older) frequent attenders were described using descriptive statistics and network analyses. Younger frequent attenders were characterised by mental illness and substance use, while older frequent attenders had high rates of physical (including chronic) diseases. Middle-aged frequent attenders were characterised by a combination of mental and physical illnesses. These findings were observed at both hospitals. Across all age groups, the network analyses between the Melbourne and Toronto hospitals were different. Among older frequent attender visits, more diagnoses were associated with high triage acuity at the Toronto hospital than at the Melbourne hospital. Some associations were similar at both sites, for example, the negative correlation between high triage acuity and joint pain. Younger, middle-aged and older frequent attenders have distinct characteristics, made readily apparent by using network analyses. Future interventions to reduce ED visits should consider the heterogeneity of frequent attenders who have needs specific to their age, presenting problems and jurisdiction.

Cost-effective analysis of preliminary single-operator cholangioscopy for management of difficult biliary stones.

Background and study aims Single-operator peroral cholangioscopy (SOC) is a therapeutic modality for difficult biliary stone disease. Given its high success rate and increasing availability, analysis of the economic impact of early SOC utilization is critical for clinical decision-making. Our aim is to compare the cost-effectiveness of different first and second-line endoscopic modalities for difficult-to-treat choledocholithiasis. Patients and methods A decision-tree model with a 1-year time horizon and a hypothetical cohort of 200 patients was used to analyze the cost-effectiveness of SOC for first, second and third-line intervention in presumed difficult biliary stones. We adopted the perspective of a Canadian tertiary hospital, omitting recurrence rates associated with endoscopic retrograde cholangiopancreatography (ERCP). Effectiveness estimates were obtained from updated meta-analyses. One-way sensitivity analyses and probabilistic sensitivity analyses were also performed to assess how changes in key parameters affected model conclusions. Results First- and second-line SOC achieved comparable clinical efficacy from 96.3 % to 97. 6 % stone clearance. The least expensive strategy is third-line SOC (SOC-3: $800,936). Performing SOC during the second ERCP was marginally more expensive (SOC-2: $ 816,584) but 9 % more effective. The strategy of first-line SOC incurred the highest hospital expenditures (SOC-1: $ 851,457) but decreased total procedures performed by 16.9 % when compared with SOC-2. Sensitivity analysis was robust in showing SOC-2 as the most optimal approach. Conclusions Second-line SOC was superior to first and third-line SOC for treatment of difficult biliary stones. When based on meta-analysis of non-heterogeneous trials, SOC-2 is more cost-effective and cost-efficient. Our study warrants a larger pragmatic effectiveness trial.

Exploring the Needs of Adults Living With Type 1 or Type 2 Diabetes Distress Using the Problem Areas in Diabetes 5 Tool

This study investigated the feasibility and acceptability of implementing a screening tool as a part of routine care and the subsequent screening experiences of patients and clinicians. Additionally, potential sources of diabetes distress (DD) were identified in this clinical population. Our investigation was a cross-sectional, mixed-methods, convenience sample of 203 patients living with type 1 or type 2 diabetes from 2 Canadian tertiary hospital-based clinics. The Problem Areas in Diabetes 5 (PAID5) scale was used to assess DD. Structured telephone interviews of patients with high DD scores and care provider focus group transcriptions were analyzed using a deductive thematic content analysis. The prevalence of DD was 45%. Lack of medication coverage (p=0.02) and presence of neuropathy (p=0.04) were approximately 5- and 2-fold more likely to be predictors of high DD, respectively. Patient interviews identified DD screening as an opportunity to share and feel supported but demonstrated their fear of discussing mental health concerns. Patients found discussion about mental health helpful and often did not require a referral to a mental health specialist. Staff focus groups discussed screening as a feasible tool, but also acknowledged barriers and knowledge gaps that preclude DD screening integration in routine clinical practice. Specialized training for clinicians may help increase confidence and improve uptake of DD screening into routine clinical practice. The prevalence of DD in outpatient care settings is high. Findings suggest that integrating the PAID5 screening tool into regular clinical practice is feasible by patients and care providers.

Comparison of single- versus double-anastomosis duodenal switch: A single-center experience with 2-year follow-up

Abstract Objective Single-anastomosis duodenal switch (SADS) has emerged in recent years as an alternative to the standard double-anastomosis duodenal switch (DADS). The objective of this study was to compare short- and medium-term outcomes between SADS and DADS. Methods Data collected in the Ontario Bariatric Registry between 2010 and 2019 were used for this retrospective study to determine outcomes of patients undergoing primary laparoscopic SADS versus DADS at a Canadian tertiary hospital and bariatric center of excellence. The primary outcome was weight loss at 1 and 2 years after surgery. Short-term secondary outcomes included operative times, intra- and early postoperative complications, hospital length of stay (LOS), and 30-day readmissions. Medium-term secondary outcomes included late postoperative complications as well as nutritional deficiencies and persistent diarrhea at 1 and 2 years after surgery. Subgroup analyses were performed to compare patients undergoing one- and two-stage procedures. Results Data of 107 patients who underwent SADS (n = 25) or DADS (n = 82) were included in the study. Follow-up data were available for 59/107 (55.1%) patients at 1 year and 47/107 (43.9%) at 2 years after surgery. Patients in the SADS and DADS groups had similar %TBWL at 1 year (23.6 versus 26.2, P = 0.617) and 2 years (24.8 versus 30.2, P = 0.116) after surgery. Short- and medium-term outcomes were similar between groups. There was no difference between patients undergoing one- versus two-stage procedures. Conclusion This study showed that patients undergoing SADS and DADS had similar weight loss at 1 and 2 years. Early and late postoperative morbidity, operative times, early readmissions, and LOS were also similar between groups. Further studies with longer follow-up are required to confirm these results.

Oxytocin Use in Trial of Labour After Cesarean Section in a Canadian Tertiary Hospital: A Retrospective Cohort Analysis

Induction of labour and oxytocin use have been associated with an increased risk of uterine rupture (UR) in patients undergoing trial of labour after cesarean (TOLAC). We aimed to quantify the risk of UR among a Canadian cohort of patients undergoing TOLAC.

Safety of direct oral challenge to amoxicillin in pregnant patients at a Canadian tertiary hospital

Penicillin allergy assessment during pregnancy relies heavily on penicillin skin testing (PST).1 Recently, Trubiano et al2 have published a validated, point-of-care penicillin allergy clinical decision tool called PEN-FAST, which predicts the chance of a positive skin test with a negative predictive value of 96.3%. However, even after negative skin testing, very few pregnant patients receive oral challenge to penicillin because of unfounded risks.3 A 2019 systematic review evaluating PST and desensitization in 231 pregnant women reported that of 203 who underwent PST, 170 tested negative.

A86 COST-EFFECTIVE ANALYSIS OF PRELIMINARY SINGLE-OPERATOR CHOLANGIOSCOPY IN MANAGEMENT OF DIFFICULT STONES

BackgroundSingle-operator peroral cholangioscopy (POC) is a therapeutic modality for difficult biliary stone disease. Given its high success rate and increasing availability, analysis of the economic impact of early POC utilization is critical for clinical decision-making.AimsWe aim to compare the cost-effectiveness of different first and second-line endoscopic modalities for difficult-to-treat choledocholithiasis.MethodsA decision tree model with a 1-year time horizon and a hypothetical cohort of 200 patients was used to analyze the cost-effectiveness of POC for first, second and third-line intervention in presumed difficult biliary stones. We adopted the perspective of a Canadian tertiary hospital, omitting complications and recurrence rates associated with ERCP. Effectiveness estimates were obtained from updated meta-analyses. One-way sensitivity analyses and probabilistic sensitivity analyses were also performed to assess how changes in key parameters affected model conclusions.ResultsFirst and second-line POC achieved comparable clinical efficacy from 95.5% to 96.5% stone clearance. The least expensive strategy is third-line POC (POC-3: $769,151). Performing POC during the second ERCP was marginally more expensive (POC-2: $770,832) but 9% more effective. The strategy of first-line POC incurred the highest hospital expenditures (POC-1: $848,141) but decreased total procedures performed by 13.4% when compared with POC-2. Sensitivity analysis was robust in showing POC-2 as the most optimal approach.ConclusionsSecond-line POC was superior to first and third-line POC for treatment of difficult biliary stones. When based on meta-analysis of non-heterogeneous trials, POC-2 is more cost-effective and cost-efficient. Our study warrants a larger pragmatic effectiveness trial. FIGURE 1: Management model for treating difficult biliary stonesPOC, peroral cholangioscopy; ERCP, endoscopic retrograde cholangioscopy. M1 indicates a decision to use ERCP. M2 indicates a decision to use POC. POC-1 – POC used as initial step. POC-2 – POC delayed until after ERCP failure. POC-3 – POC delayed until two failed ERCP attempts.Funding AgenciesNone

Mifepristone-Misoprostol Use for Second- and Third-Trimester Medical Termination of Pregnancy in a Canadian Tertiary Care Centre

This study aims to evaluate the impact of the implementation a mifepristone-misoprostol protocol (MIFE/MISO) on the induction-to-expulsion interval in the context of second- and third-trimester pregnancy termination or intrauterine fetal death (IUFD) compared with misoprostol alone (MISO), and to share the experience of a Canadian tertiary hospital concerning the feasibility and safety of such a protocol. This is a single-centre retrospective pre-post cohort study carried out at the Centre Hospitalier Universitaire (CHU) Sainte-Justine between 2017 and 2019. Women in the MIFE/MISO group were instructed to take mifepristone 24-48 hours before induction. Induction in the MIFE/MISO group was performed with misoprostol dosages adjusted to gestational age and the presence of previous uterine scars, while, in the MISO group, all patients received 400 μg of misoprostol vaginally every 4 hours. Ninety-four patients were included in the MIFE/MISO group and 103 patients, in the MISO group. Median time to expulsion was significantly lower in the MIFE/MISO group than the MISO group (13.5 and 19.5 h respectively; P < 0.001). The total dose of misoprostol administered was significantly lower in the MIFE/MISO group than the MISO group, and adverse effects were reported in 60% and 82% of patient records, respectively (P < 0.001). Complication rates were similar between the 2 groups. The MIFE/MISO protocol is highly effective for second- and third-trimester induction for pregnancy termination or IUFD, without increasing complication rates and with fewer reported adverse effects. Its implementation is safe and feasible in a tertiary medical centre.

Articulating viewpoints to better define and respond to the needs of adolescents and young adult survivors of pediatric brain tumors

Purpose Adolescents and young adult survivors of pediatric brain tumors (AYA-PBTS) often experience difficulties with social skills, pursuit of studies and employment. This study explored pediatric long-term survivors’ perspective on their post-treatment needs and ways to improve resources and interventions. Methods We used an original method of three sequential focus group interviews by adding the perspectives of survivors (15–22 years), parents and health professionals (total N = 22). Participants were recruited using purposive sampling from the long-term follow-up clinic at a Canadian tertiary hospital. We used computer-assisted analysis to draw themes from each group and compare thematic content across groups. Results Categorization of participants’ responses resulted in three domains: personal life, education and work. Participants mentioned the improvement of communication tools to facilitate access to timely information, the organization of counseling to improve employment integration, and tailoring interventions to optimize the return to daily activities in aftercare. Subsequent inductive analysis revealed three overarching trends among groups: multipurpose social networking, AYA-PBTS-specific information websites and transition tools and procedures. Conclusion and implications for psychosocial providers This study identified solutions for AYA-PBTS’ specific needs in aftercare. This population needs up-to-date post-treatment information and refined outreach procedures. Future research should define and prioritize these suggested solutions.

Recognition of Long-COVID-19 Patients in a Canadian Tertiary Hospital Setting: A Retrospective Analysis of Their Clinical and Laboratory Characteristics.

A proportion of patients with COVID-19 have symptoms past the acute disease phase, which may affect quality of life. It is important for clinicians to be aware of this “long-COVID-19” syndrome to better diagnose, treat, and prevent it. We reviewed clinical and laboratory characteristics of a COVID-19 cohort in a Toronto, Ontario tertiary care center. Demographic, clinical, and laboratory data were collected, and patients were classified as “long-COVID-19” or “non-long-COVID-19” using consensus criteria. Of 397 patients who tested positive for COVID-19, 223 met inclusion criteria, and 62 (27%) had long-COVID-19. These patients had a similar age distribution compared to non-long-COVID-19 patients overall but were younger in the admitted long COVID-19 group. The long-COVID-19 group had more inpatients compared to the non-long-COVID-19 group (39% vs. 25%) and more frequent supplemental oxygen or mechanical ventilation use. However, long-COVID-19 patients did not differ by duration of mechanical ventilation, length of stay, comorbidities, or values of common laboratory tests ordered. The most frequent symptoms associated with long-COVID-19 were fatigue and weakness, as reported most commonly by the infectious disease, respirology and cardiology disciplines. In conclusion, by retrospective chart review, 27% of COVID-19 patients presenting to a tertiary care center in Toronto, Canada, were found to meet criteria for long-COVID-19. Past medical history and routine laboratory testing at presentation did not predict for long-COVID-19 development.

The Bowel CLEANsing National Initiative: High-Volume Split-Dose Vs Low-Volume Split-Dose Polyethylene Glycol Preparations: A Randomized Controlled Trial

The aim of this study was to compare high-volume polyethylene glycol (PEG) with low-volume PEG with bisacodyl split-dosing regimens. Adult outpatients in 10 Canadian tertiary hospitals were randomized, stratified by morning or afternoon colonoscopy, to high-volume split-dose PEG (2 L+ 2 L) (High-SD) or low volume (1 L+ 1 L)+ bisacodyl (15 mg) PEG (Low-SD), with a second randomization to liquid or low-residue diets. The primary end point, using noninferiority hypothesis testing, was adequate bowel cleansing (Boston Bowel Preparation Scale total score of ≥6, with each of 3 colonic segments subscores ≥2). Secondary objectives were willingness to repeat the preparation, withdrawal time, cecal intubation, and polyp detection rates. Over 29 months, 2314 subjects were randomized to High-SD (N= 1157) or Low-SD (N= 1157) (mean age, 56.2 ± 13.4 y; 52.1% women). Colonoscopy indications were 38.2% diagnostic, 36.8% screening, and 25.0% surveillance, with no between-group imbalances in patient characteristics. Low-SD satisfied noninferiority criteria vs High-SD for adequate bowel cleanliness with only marginally inferior results (90.1% vs 88.1%; P= .02; difference, 2.0%; 95% CI [0.0%; 4.5%]). High-SD was associated with lower willingness to repeat (66.9% vs 91.9%; P < .01), was less well tolerated (7.3 ± 2.3 vs 8.1 ± 1.9; P < .01), causing more symptoms. No differences in procedural outcomes were noted except for more frequent cecal intubation rates after High-SD (97.4% vs 95.6%; P= .02). Among the High-SD group, adequate bowel preparation was greater after a clear liquid diet (93.6% vs 87.9%; P < .01), a finding not seen in the Low-SD group. Low-SD is noninferior to High-SD in providing adequate bowel preparation. Low-SD results in fewer symptoms, with greater willingness to repeat and tolerability. The overall impact of diet was modest.The study was approved by the research ethic boards from all sites and was registered at ClinicalTrials.gov (NCT02547571).

Comparison of single- versus double-anastomosis duodenal switch: a single-center experience with 2-year follow-up.

Single-anastomosis duodenal switch (SADS) has emerged in recent years as an alternative to the standard double-anastomosis duodenal switch (DADS). The objective of this study was to compare short- and medium-term outcomes between SADS and DADS. Data collected in the Ontario Bariatric Registry between 2010 and 2019 were used for this retrospective study to determine outcomes of patients undergoing primary laparoscopic SADS versus DADS at a Canadian tertiary hospital and bariatric center of excellence. The primary outcome was weight loss at 1 and 2 years after surgery. Short-term secondary outcomes included operative times, intra- and early postoperative complications, hospital length of stay (LOS), and 30-day readmissions. Medium-term secondary outcomes included late postoperative complications as well as nutritional deficiencies and persistent diarrhea at 1 and 2 years after surgery. Subgroup analyses were performed to compare patients undergoing one- and two-stage procedures. Data of 107 patients who underwent SADS (n = 25) or DADS (n = 82) were included in the study. Follow-up data were available for 59/107 (55.1%) patients at 1 year and 47/107 (43.9%) at 2 years after surgery. Patients in the SADS and DADS groups had similar %TBWL at 1 year (23.6 versus 26.2, P = 0.617) and 2 years (24.8 versus 30.2, P = 0.116) after surgery. Short- and medium-term outcomes were similar between groups. There was no difference between patients undergoing one- versus two-stage procedures. This study showed that patients undergoing SADS and DADS had similar weight loss at 1 and 2 years. Early and late postoperative morbidity, operative times, early readmissions, and LOS were also similar between groups. Further studies with longer follow-up are required to confirm these results.

Cross-sectional study of pediatric pain prevalence, assessment, and treatment at a Canadian tertiary hospital

ABSTRACT Background Painful experiences are common among hospitalized children. Long-term negative biopsychosocial consequences of undertreated pain are recognized. Aims The study benchmarks pain prevalence, assessment, and treatment as first steps to improve pain care in a Canadian tertiary hospital. Methods Single-day audits were undertaken on the pediatric ward (PW), pediatric emergency department (ED), and maternal services (MS). Participants (child or caregiver proxy) reported hospital pain experiences in the preceding 24 h; medical records were reviewed for assessment and treatment. Results Among 84 participants, pain prevalence ranged from 75% to 88%; mean pain intensity ranged from 5.7 to 6.5/10. Prevalence of moderate to severe pain was 78% on PW, 65% in ED, and 55% on MS; needle pokes were the most frequent cause of worst pain. Documentation of pain assessment varied by setting (PW, 93%; ED, 13%; MS, 0%). Documented maximum pain scores were significantly lower compared to participant report (mean difference 4.5/10, SD 3.1, P < 0.0001). A total 29% (6/21) of infants with heel lance or injection received breastfeeding or sucrose, and 29% (7/24) of participants receiving other needle procedures had documented or reported topical lidocaine use. All participants on MS underwent needle procedures. Conclusions Pain is experienced commonly by infants and children in PW, ED, and MS. Pain assessment documentation is not routine and underestimates participant report. Evidence-based pain management strategies are underutilized. An institution-wide quality improvement approach is required to address pain care. Pain assessment and needle pain prevention and treatment should be prioritized in these pediatric acute care and newborn care settings.

16177 Assessment of conjunctivitis occurring in patients with long-term use of dupilumab for the treatment of atopic dermatitis in clinical practice

An ongoing safety concern with dupilumab treatment for atopic dermatitis has been the high incidences of conjunctivitis. While incidences of conjunctivitis ranged from 5%-28% in clinical trials, subsequent real-world studies have reported rates of up to 50%. However, implications of the adverse event (AE) with long-term use of dupilumab remains largely unknown. To further characterize conjunctivitis and other ocular surface disorders (OSD) with long-term dupilumab treatment, a retrospective chart review was conducted of consecutive patients receiving dupilumab at two Canadian tertiary hospitals. Fifty-eight patients met inclusion criteria (≥52 weeks of dupilumab or discontinued before 52 weeks due to an OSD) and 2 patients were excluded for missing 52-week appointment data. 21/58 patients (36%) reported conjunctivitis or other OSDs. Onset of symptoms ranged from week 1-32 of treatment, with 17/21 cases (81%) occurring in the first 16 weeks. Despite high incidences of OSDs early on, only 52% of cases resolved, 14% of cases improved, and 24% of cases were ongoing by week 52. Two patients discontinued due to ocular AEs. While one patient discontinued solely due to ocular symptoms at week 48, another discontinued due to watery eyes in conjunction with nonocular symptoms (arthralgia, symmetric numbness) at week 19. Although a majority (81%) of the onset of conjunctivitis occurred in the first 16 weeks, many patients (38%) experienced persistent symptoms even at week 52. Therefore, closer follow-up appointments are recommended to optimize management of patients with ocular symptoms at week 16, as symptoms may persist and impact treatment adherence.

16280 Sixteen-week efficacy and safety results of 93 patients treated with dupilumab for moderate to severe atopic dermatitis

Despite promising efficacy and safety results demonstrated by dupilumab for the treatment of moderate to severe atopic dermatitis in clinical trials, our understanding of dupilumab in clinical practice remains limited in literature. Real-world studies are especially important with strict inclusion and exclusion criteria of RCTs limiting generalizability of data to patients in everyday practice. Therefore, a retrospective chart review was conducted of consecutive patients on dupilumab from December 2017 to May 2019 at 2 Canadian tertiary hospitals.

Budget Impact Analysis of Preoperative Radioactive Seed Localization.

This study models costs in implementing a radioactive seed localization (RSL) program for nonpalpable breast lesions at a large Canadian tertiary hospital to replace existing wire-guided localization (WGL). All direct and indirect operating costs of localization per lesion from the hospital's perspective were determinedby retrospectively reviewing patient data and costs from January 2014to December 2016. A budget impact analysis and sensitivity analysis were performed to calculate the mean cost per lesion, the minimum and maximum cost per lesion, operational costs, and initial costs. There were 265 WGL lesions in 2014 and 170 RSL lesions in 2016 included in cost calculation. The mean cost per localization was $185 CAD for WGL ($148-$311) and $283 CAD ($245-$517) for RSL using preloaded seeds, adjusted to 2016 Canadian dollars. The annual operational expenditure including all localizations and overhead costs was $49,835 for WGL and $80,803 for RSL. Initial costs for RSL were $22,000, including external training and new equipment purchases. Our budget impact analysis shows that RSL using preloaded radioactive seeds was more expensive than WGL when considering per-lesion localization costs and specific costs related to radiation safety. Manually loading radioactive seed could be a cost-saving alternative to purchasing preloaded seeds.Our breakdown of costs can provide a framework for other centres to determine which localization method best suit their departments.