Multivariable Logistic Regression Models Research Articles

Comparative Safety of Ibrutinib Versus Zanubrutinib in Patients With Chronic Lymphocytic Leukemia: A Prospective Cohort Study.

This study compares the safety profiles of two Bruton's tyrosine kinase (BTK) inhibitors, Ibrutinib and Zanubrutinib, in patients with chronic lymphocytic leukemia (CLL). While Ibrutinib has transformed CLL treatment, it is associated with significant adverse events (AEs). Zanubrutinib, a second-generation BTK inhibitor, offers potential for improved safety. In this prospective study, 200 CLL patients were enrolled, with 100 receiving Ibrutinib and 100 receiving Zanubrutinib. Baseline characteristics such as age, sex, body mass index (BMI), Eastern Cooperative Oncology Group (ECOG) performance status, and genetic factors were evaluated. AEs and serious AEs (SAEs) were tracked and graded using the Common Terminology Criteria for Adverse Events (CTCAE). Multivariate logistic regression models were conducted to determine predictors of SAE and AEs grade ≥ 3. Adjusted odds ratio (aOR) and 95% confidence interval (CI) were reported. The mean ages of the Ibrutinib and Zanubrutinib groups were 49.65 and 49.16years, respectively (p=0.285). The Zanubrutinib group had a higher percentage of patients with worse ECOG status (71% vs. 57%, p=0.039). Fewer Zanubrutinib patients experienced severe AEs (4% vs. 9%, p=0.152) or SAEs (8% vs. 17%, p=0.054). Neutropenia occurred only in the Ibrutinib group (3%). Subgroup analysis showed a higher complication rate with Zanubrutinib in non-refractory patients (11.40% vs. 5.26%, p=0.065). Stage III CLL was a protective factor of grade ≥ 3 AEs (aOR=0.007; 95% CI: 0.0003-0.1829) and SAE (aOR=0.015; 95% CI: 0.001-0.177). While ECOS status (2 vs. 3) resulted in reduced risk of SAE, chromosome 17p deletion emerged as the main risk factor of SAE (aOR=6.40; 95% CI: 1.33-30.79). Zanubrutinib demonstrated a more favorable safety profile than Ibrutinib, with fewer severe adverse events. It may be a safer alternative for CLL patients, particularly those at higher risk for complications from BTK inhibitors. However, these differences stemmed from variability in baseline clinical characteristics rather than the interventions themselves.

P-616. Sociodemographic and Clinical Factors Affecting Vaccination after Pediatric Solid Organ Transplantation at Duke University

Abstract Background Pediatric solid organ transplant (SOT) recipients are at increased risk for vaccine preventable illnesses (VPI). They frequently receive vaccines after transplantation when immunosuppressive medications and cytopenias may impact their immune response to routine childhood vaccines. Current guidelines recommend monitoring vaccine-specific serologies to ensure optimal vaccine responses and to guide the need for repeat doses. Methods In this single-center retrospective cohort study, a multivariate logistic regression model was used to determine the sociodemographic and clinical factors associated with delays in starting post-transplant vaccines and adherence to post-vaccine serologic monitoring among 199 pediatric patients who received a SOT at Duke University between 2014-2023. The prevalence of cytopenias at the time of post-transplant vaccination was also described. Results Out of 150 children eligible for post-transplant vaccines (Table1), 48 (32%) failed to start catch-up vaccines within 2 years of transplantation. Older children (OR=0.877, 0.83-0.927) and children with private insurance (OR=0.458, 0.211-0.993) had significantly decreased odds of early catch-up vaccines (Table 2). Hepatitis B serologies were obtained in 23% of patients after post-transplant vaccination, but titers against the remaining non-live childhood vaccines were only obtained in 1-8% of children (Table 3). Approximately 53% of all children had neutropenia or lymphopenia (less than 1500 x 10^6 cells/L) at the time of post-transplant vaccination, with heart and intestinal/multi-visceral transplant recipients having the highest rates at ∼75% (Table 4). Conclusion These findings identify pediatric SOT recipients most at risk for delayed post-transplant vaccines. The associations between vaccine delay and private insurance and older age warrant further investigation. The extremely low rates of vaccine-specific serologic monitoring and the high prevalence of cytopenias at the time of vaccination raise concerns that pediatric SOT recipients are insufficiently protected from VPI. Future work will determine the impact of cytopenias on vaccine response and will address inequities in vaccination among pediatric SOT recipients. Disclosures All Authors: No reported disclosures

The Association Between the Triglyceride–Glucose Index, Its Combination with the Body Roundness Index, and Chronic Kidney Disease in Patients with Type 2 Diabetes in Eastern China: A Preliminary Study

Objectives: This study aimed to investigate the relationship between the triglyceride–glucose (TyG) index, its combination with the body roundness index (BRI), and chronic kidney disease (CKD) in patients with type 2 diabetes mellitus (T2DM) based on a cross-sectional analysis conducted in Eastern China. Methods: The research originates from a cross-sectional study performed in Zhejiang Province, Eastern China, between March and November 2018. The TyG-BRI index was calculated based on triglyceride, fasting blood glucose, and the BRI. The correlation between the TyG-BRI index and the risk of CKD was assessed using a restricted cubic spline model. A multivariate logistic regression model was used to investigate the association between the TyG-BRI index and the risk of CKD. Receiver operating characteristic (ROC) analyses was used to evaluate the optimal cut-off and value of the TyG-BRI index for predicting CKD. Results: A total of 1756 T2DM participants were enrolled in this study. The TyG-BRI index was significantly higher in participants with CKD than in those without CKD. In the fully adjusted model, the odds ratios for CKD in the second, third, and fourth TyG-BRI quartiles were 0.93 (95% CI: 0.65–1.33), 1.33 (95% CI: 0.94–1.88), and 1.57 (95% CI: 1.10–2.25), respectively, compared to the first quartile. RCS analysis confirmed a linear dose–response relationship between the TyG-BRI index and CKD risk (all p for nonlinearity > 0.05). ROC curve analysis revealed that the TyG-BRI index had moderate predictive value for CKD, with an area under the curve of 0.626 (95% CI: 0.597–0.656, p < 0.001). The optimal cut-off value for the TyG-BRI index was 42.46, with a sensitivity of 68.2% and specificity of 52.2%. Conclusions: The TyG-BRI index was positively associated with the risk of CKD in a T2DM population, demonstrating a dose–response relationship and moderate predictive value. It may serve as a valuable tool for identifying high-risk individuals and informing targeted interventions to prevent or delay CKD progression in this population.

P-786. Rates of Treatment Discontinuation over Time with Rifampin versus Isoniazid for Latent Tuberculosis Infection: A 6-year Experience at a Large Safety-Net Clinic

Abstract Background Treatment of latent tuberculosis infection (LTBI) is a crucial component of tuberculosis (TB) eradication plans in the United States (US). It is estimated that 80% of active TB cases arise from LTBI reactivation. Numerous gaps have been identified in the LTBI care cascade, leading to low rates of treatment initiation and completion. Treatment duration has shown to be a significant factor influencing completion rates for LTBI treatment. Since 2020, the Center for Disease Control and Prevention (CDC) recommends 4 months of daily rifampin (4R) as the preferred regimen for LTBI, while 6 to 9 months of isoniazid (9H) is now considered an alternative regimen.Table 1.Characteristics of the Patients by Drug Used Methods We conducted a retrospective cohort analysis including all patients treated for LTBI with 4R or 9H (May 2015 - September 2021) at the Boston Medical Center/Boston Public Health Commission TB Clinic. The primary objective was to compare completion rates between patients with LTBI treated with 4R versus 9H. For this, completion of 95% of the planned course was considered sufficient. We also compared rates of treatment discontinuation by plotting a survival curve. Data analysis was performed with R statistical software (version 4.3.2). The study was approved by the Institutional Review Board (IRB) of Boston University.Figure 1.Rates of Treatment Discontinuation over Time for Rifampin versus Isoniazid Results A total of 2178 patients with a median age of 40 years-old were treated for LTBI during the study period, 958 (43.99%) with 4R and 1220 (56.01%) with 9H (Table 1). The completion rates differed significantly, with 652 (68.1%) completing 4R compared to 550 (45.1%) completing 9H (p < 0.001). A Kaplan-Meier curve showed similar rates of discontinuation over time between the 2 regimens (Figure 1). After adjusting for key confounders using multivariable logistic regression model, the sole variable significantly associated with LTBI treatment completion was the use of 4R with an odds ratio of 2.805 (95% CI: 2.313 - 3.406) (p < 0.001) (Table 2).Table 2.Factor's Association with Treatment CompletionOR: odds ratio; CI: confidence interval Conclusion Our findings confirm that 4R has better completion rates than 9H. Importantly, treatment completion on the survival curve was similar in the first 4 months of therapy, supporting the notion that treatment duration is a key factor determining LTBI treatment completion rate regardless of the drug used. Disclosures All Authors: No reported disclosures

P-204. Contemporary Economic and Healthcare Burden Associated with Clostridiodes difficle Infections (CDI) in the United States

Abstract Background Centers for Disease Control and Prevention (CDC) estimated that in 2017, there were 223,900 cases of CDI in hospitalized patients and 12,800 deaths in the United States. CDI is the most common health care-associated infection, and a leading cause of diarrhea in the hospitalized patients (Magill et. al., 2015). Incidence of Community-associated CDI is rising in recent years (Chitnis et. al., 2013; Gerding & Lessa 2015). Methods The National Inpatient Samples (NIS) datasets include de-identified patient-specific and hospital-specific information for hospitalized patients across the U.S. We utilized these datasets to study the economic and healthcare burden associated with CDI. Data were downloaded and SAS software was used for analyses. Continuous variables were summarized by means and standard deviations and compared using Student’s t-tests. Categorical variables were summarized by percentages and compared using Chi-squared or Fisher’s tests, as appropriate. Bivariate and multivariable logistic regression models were created to determine factors that are associated with the primary outcome.Table 1:Patient Characteristics Results A total of 10,806 cases of CDI were identified among in-patient samples of 1818,090 patients during 2017-2019 in 9 geographic regions across the United States. This constitutes 10% sample of the NIS dataset. Compared to 2017, significant increase in CDI was observed in 2018 and 2019 (12% vs 46 and 41% respectively). Of the patient population, mean age at admission was 66 years; white had the highest cases of CDI compared to any other race (p < 0.001). Majority of the CDI cases were observed in teaching hospitals compared to community hospitals (71% vs 9.3%; p=< 0.001). South Atlantic region had the highest CDI burden (20%) followed by East North Central region (18%). Large hospitals based on bed size observed significantly higher cases of CDI (51%, p = 0.017). Hospitalization charges was significantly higher among CDI patients (mean $ 109,798 vs $56,530; p = < 0.001). Conclusion These results highlight the significant disease morbidity and mortality as well as economic burden caused by CDI and warrants effective mitigation strategies to address the risk factors to minimize CDI. Disclosures All Authors: No reported disclosures

P-234. Clinical Factors Associated with Central Line Associated Blood Stream Infections (CLABSI) in Hospitalized Dialysis Patients

Abstract Background We sought to understand factors associated with Central Line Associated Blood Stream Infections (CLABSI) in hospitalized patients receiving dialysis. Methods 7353 patients hospitalized between 2019 and 2021 with an ICD-10 code for dialysis and who had a central line accessed during their stay were identified. Demographics, comorbidities, central line characteristics, and length of stay data were collated from the electronic health record and linked to infection prevention CLABSI data. 38 cases on dialysis at the time of CLABSI were identified and matched to controls who did not have a CLABSI. Controls were matched to cases (2:1) by age (+/- 10 years), race, facility, admission date (+/-6 months) and intensive care unit admission during their stay. 2 cases were excluded due to inability to match. Descriptive statistics were performed. Univariate and multivariable logistic regression models were used to assess for factors associated with increased odds of CLABSI. Results Dialysis patients with CLABSI were predominantly Black and male. 76% of cases were admitted to the ICU during their stay and 33% died within 30 days of CLABSI. Tunneled catheters, non-tunneled catheters and arteriovenous fistula/graft (AVF/G) were present in 50%, 31% and 14% of patients respectively at time of CLABSI. Cases were more likely than controls to have a non-tunneled catheter for hemodialysis access, longer length of stay, longer central line duration, and have had a transplant. (Table 1) Patients with non-tunneled catheters were 13 times more likely to have a CLABSI than those with AVF/G (p 0.02). Patients who received dialysis prior to admission had lower odds of CLABSI compared to acute dialysis patients (OR 0.5, p 0.08). (Table 2) After adjustment for age, sex, history of transplant, and being on dialysis prior to admission, increased length of stay (OR 1.03, p 0.01) and use of non-tunneled catheter for dialysis (OR 10.2, p 0.03) remained associated with increased odds of CLABSI. (Table 3) Conclusion The use of non-tunneled catheters and longer length of stay were identified as key predictors of CLABSI in patients on dialysis. These findings emphasize the need for strict infection control measures and careful monitoring of catheter types in this vulnerable population. Disclosures All Authors: No reported disclosures

P-604. Preliminary real-world Abrysvo vaccine effectiveness (VE) against Respiratory Syncytial Virus (RSV)-related lower respiratory tract disease (LRTD) hospitalizations and emergency department (ED) visits—Kaiser Permanente of Southern California (KPSC), November 2023-April 2024

Abstract Background While the pivotal randomized clinical trial documented the efficacy of the RSVpreF vaccine (Abrysvo) against RSV-related LRTD, the limited number of hospitalizations and ED visits hampered VE assessment for these clinical outcomes. We evaluated Abrysvo’s effectiveness against 1st occurrence of RSV-related inpatient or ED LRTD in KPSC, a large US healthcare system.Table 1.Characteristics of study population, KPSC Methods In this test-negative case control study, we assessed VE among adults ≥60 years of age by analyzing KPSC members’ electronic health records and enhancing specimen testing from 11/24/2023-4/9/2024. Events from inpatient or ED settings meeting an ICD-10 code-based LRTD case definition with a respiratory specimen tested on GenMark RP2 expanded multiplex PCR assay were included. Cases were defined as RSV+ episodes. Analyses were conducted using two sets of pre-specified controls: 1) ‘Strict’: RSV- and positive for a non-vaccine preventable disease (VPD) etiology, and 2) ‘Broad’: all RSV-. The strict approach accounted for lower sensitivity of RSV testing among adults and potential bias associated with VPD controls. Exposure was defined as Abrysvo receipt ≥21 days before encounter. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated from a multivariable logistic regression model with adjustment for patient demographic and clinical characteristics. VE was calculated as 1−OR multiplied by 100%.Table 1.Characteristics of study population, KPSC, cont. Results The overall study population included 4,469 KPSC members: >50% were ≥75 years, 93% had ≥1 comorbidities, and 15% immunocompromised. In the strict analysis, there were 425 cases and 522 controls who received Abrysvo a median of 59 days before illness onset; VE compared to no vaccine receipt was 84% (95% CI: 29–97). In the broad analysis, there were 425 cases and 4,044 controls who received Abrysvo a median of 53 days before illness onset; adjusted VE was 82% (95% CI: 28–96).Table 2.Abrysvo Vaccine Effectiveness against RSV LRTD hospitalizations and ED visits, KPSC Conclusion This study demonstrated real world VE of Abrysvo during its first 5 months of use against severe LRTD in the hospital and ED settings among US adults ≥60 years of age. These results expand on efficacy results from clinical trial populations by including a substantial number of persons age 75+ years and with comorbidities and immunocompromising conditions. Disclosures Sara Y. Tartof, PhD MPH, GSK: Grant/Research Support|Pfizer Inc: Grant/Research Support Negar Aliabadi, MD, MS, Pfizer Inc: employment|Pfizer Inc: Stocks/Bonds (Public Company) Jeff Slezak, MS, Dynavax Technologies: Grant/Research Support|Pfizer: Grant/Research Support Vennis Hong, MPH, Pfizer: Grant/Research Support Bradley Ackerson, MD, Dynavax: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Moderna: Grant/Research Support|Pfizer: Grant/Research Support Qing Liu, M.S., Pfizer Inc.: Stocks/Bonds (Public Company) Sally Shaw, DrPH, MPH, Pfizer: Grant/Research Support Sabrina Welsh, MPH, Pfizer Inc: Stocks/Bonds (Public Company) Julie Stern, MPH, GlaxoSmithKline: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi: Grant/Research Support Michael Dutro, PharmD, Pfizer: Stocks/Bonds (Public Company) Erica Chilson, PharmD, Pfizer Inc: Employee|Pfizer Inc: Stocks/Bonds (Public Company) Elisa Gonzalez, MS, Pfizer: Stocks/Bonds (Private Company) Robin Hubler, MS, Pfizer, Inc.: Employee of Pfizer Inc.|Pfizer, Inc.: Stocks/Bonds (Private Company) Luis Jodar, PhD, Pfizer Inc: Employment|Pfizer Inc: Stocks/Bonds (Public Company) Bradford D. Gessner, M.D., M.P.H., Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Elizabeth Begier, MD, M.P.H., Pfizer Vaccines: Employee|Pfizer Vaccines: Stocks/Bonds (Private Company)

P-193. Risk Factors Associated with Patients Diagnosed with Clostridioides difficile Infection with no Documented Antibiotic Exposures

Abstract Background Clostridioides difficile infection (CDI) is a common healthcare-associated infection leading to significant morbidity and mortality. Antibiotic exposure is a primary risk factor associated with CDI, but other common risk factors for include advanced age, frequent hospitalization, immunosuppression, previous CDI, and gastric acid suppression. This study aimed to evaluate factors associated with CDI with no documented antibiotic exposure. Methods This is a case-control study of 131 patients with a positive C. difficile (CD) test between 7/2022 - 6/2023 at the Edward Hines Jr., VA Hospital. Incident cases were defined as a patient with a positive CD test with no documented antibiotic exposures within 120 days prior to diagnosis, and controls were patients with a positive CD test with documented antibiotic exposures. A multivariable logistic regression model was constructed to determine the adjusted odds ratio (aOR) and 95% confidence intervals (CI) for key CDI risk factors associated with primary CDI and no antibiotic exposure. Available stools were cultured, and recovered CD isolates underwent PCR-ribotyping (RT). Results Among all patients, 60% (78/131) had primary CDI, 20% (26/131) had recurrent CDI, and 20% (27/131) were presumed colonized. Among patients with primary CDI, 20% (16/78) had no documented antibiotic exposure. (Table 1) Unadjusted analysis revealed that patients with primary CDI and no antibiotic exposure had increased odds of 1) being age < 65 (crude OR [cOR] 4.41; CI 1.41 – 14.50) 2) having a stool toxin EIA negative test (cOR 5.06; CI 1.27 – 34.00), 3) being classified as a community onset CDI (CO-CDI) (cOR 5.32; CI 1.63 – 20.90). After adjusting for potential confounding variables, patients had increased odds of being age < 65 (aOR 3.52; CI 1.02 – 12.80) and being classified as a CO-CDI (aOR 4.58; CI 1.30 – 19.10). (Table 2) RT106 was the most common strain identified, but there was no strain type associated with a lack of antibiotic exposure. Conclusion Patients diagnosed with CDI and no antibiotic exposures appear to be younger, frequently toxin EIA negative, and are more likely to have a community-onset CDI. Further research is required to determine if there are atypical risk factors within the community that place these patients at risk of developing a CDI. Disclosures Larry K. Kociolek, MD, MSCI, Merck: Grant/Research Support Curtis Donskey, MD, Clorox: Grant/Research Support|Pfizer: Grant/Research Support Stuart Johnson, M.D., Acurx Pharmaceuticals: Advisor/Consultant|Bio-K Plus International: Advisor/Consultant|Ferring Phamraceuticals: Advisor/Consultant Dale N. Gerding, MD, AstraZeneca: Advisor/Consultant|Destiny Pharma: Advisor/Consultant|Destiny Pharma: Licensed IP to Destiny|Sebela: Advisor/Consultant|Sebela: Licensed IP Andrew M. Skinner, MD, BioK plus: Advisor/Consultant|Ferring Pharmaceuticals: Advisor/Consultant|Recursion pharmaceutical: Advisor/Consultant

P-691. Characteristics Associated with the Presence of One or More Risk Factors for Severe Respiratory Syncytial Virus Disease among Adults in the United States

Abstract Background Respiratory syncytial virus (RSV) can cause severe disease in older adults and adults with certain medical conditions. In June 2023, RSV vaccination was recommended for United States (US) adults ≥60 years of age (YoA) using shared clinical decision-making. This study explored factors associated with having diagnosed and undiagnosed risk factors (RFs) for severe RSV disease among US adults. Methods A retrospective analysis of pooled National Health and Nutrition Examination Survey data from 4 survey waves (January 2011 - March 2020) was conducted, comprising adult respondents (≥20 YoA), and weighted to allow extrapolation to all non-institutionalized US adults (Table 1). Diagnosed RFs were identified via self-report; undiagnosed RFs were assessed via lab test/exam results (limited to diabetes and renal disease). Multivariable logistic regression models were developed to assess associations between respondents’ sociodemographic characteristics and presence of ≥1 RF for severe RSV disease (cardiopulmonary, endocrine, and metabolic conditions). Results After extrapolation to the US population, 35.5% of adults ≥20 YoA (n=82,715,916/233,102,301) had ≥1 RF (diagnosed or undiagnosed) for severe RSV disease. For both diagnosed and undiagnosed RFs, older age, lower income, being a smoker, and obesity were associated with significantly higher odds of having ≥1 RF (Table 2). Adults with government insurance had a higher likelihood of having ≥1 diagnosed RF compared with those with private insurance (p < 0.05). Adults from racial and ethnic minority groups were more likely than non-Hispanic White adults to have ≥1 undiagnosed RF (p < 0.01). Compared to adults whose routine place for healthcare was doctors’ offices, adults with no routine place were less likely to have ≥1 diagnosed RF (p < 0.001), while those whose routine place was the emergency room were less likely to have ≥1 undiagnosed RF (p < 0.05). Conclusion Among US adults, several social determinants of health are associated with the presence of ≥1 diagnosed and undiagnosed RF for severe RSV disease. Understanding characteristics associated with RFs for severe RSV disease can help to ensure RSV vaccination among these higher risk groups. Funding: GSK (GSK study identifier: VEO-000686) Disclosures Emily K. Horn, MSc, GSK: employee|GSK: Stocks/Bonds (Private Company) David Singer, PharmD, MS, GSK: employee|GSK: Stocks/Bonds (Public Company) Alison Booth, MSc, GSK: Grant/Research Support|Other pharmaceutical, biotech, and medical device companies: Grant/Research Support Cynthia Saiontz-Martinez, MSc, GSK: Grant/Research Support|Other pharmaceutical, biotech, and medical device companies: Grant/Research Support Ariel Berger, MPH, GSK: Grant/Research Support|Other pharmaceutical, biotech, and medical device companies: Grant/Research Support

Cardiometabolic index as a predictor of gallstone incidence in U.S. adults: insights from NHANES 2017–2020

BackgroundGallstone disease (GSD) is associated with obesity. The Cardiometabolic Index (CMI), a metric that accurately assesses central adiposity and visceral fat, has not been extensively studied in relation to GSD risk. This study investigates the link between CMI and GSD incidence in U.S. adults.MethodsThis study utilized data from the National Health and Nutrition Examination Survey(NHANES)(2017–2020) to assess the association between CMI and GSD, adjusting for confounders such as age, sex, race, chronic diseases, and lifestyle factors. Multivariable logistic regression models and subgroup analyses were employed. Generalized Additive Models (GAM) and advanced curve fitting techniques were used to explore potential non-linear relationships, with threshold effects determined via piecewise linear regression if such relationships were identified. Receiver Operating Characteristic (ROC) curves evaluated and compared the predictive performance of CMI, Body Mass Index (BMI), and Waist Circumference (WC), establishing optimal cutoff values along with their sensitivity and specificity.ResultsThis study included 3,706 participants, of whom 10.6% (392) had GSD. Participants with GSD showed significantly higher CMI values (0.57 vs. 0.44, P = 0.0002). The GSD group included more females and older adults, with increased risks for hypertension, diabetes, higher serum cholesterol and creatinine levels, and a higher risk of cancer. Logistic regression analysis revealed that higher CMI was significantly associated with greater GSD incidence (OR = 1.19, 95% CI = 1.02–1.38, P < 0.0001). The ROC curve demonstrated superior predictive performance (AUC = 0.778), outperforming conventional metrics like BMI and WC. GAM analysis indicated a non-linear positive correlation between CMI and GSD, with an optimal threshold of 0.996. Subgroup analysis found the strongest association among females, individuals aged 20–39, non-Hispanic Whites, those without a history of coronary heart disease, and alcohol consumers.ConclusionOur study reveals a nonlinear positive correlation between the CMI and the incidence of GSD among U.S. adults, with a threshold value of 0.996. Despite limitations in sample size that constrained the analysis of a fully adjusted model, after adjusting for confounding factors, the AUC for predicting GSD using CMI reached 0.778, surpassing traditional metrics. These findings underscore the importance of CMI as a critical risk factor and emphasize the necessity of targeted interventions for high-risk populations.

P-473. Health Care Resource Use Burden Among People With HIV (PWH) and Concurrent Mental Health Disorders (MHDs): Claims Analysis of Treatment-Naïve Medicaid Population Initiating Multi-Tablet Regimens (MTRs) vs. Single-Table Regimens (STRs)

Abstract Background Multi-tablet antiretroviral (ART) regimens (MTRs) have been largely replaced by single-tablet ART regimens (STRs) for treating people with HIV(PWH). STRs provide lower pill burden, increased patient adherence, and lower health care resource utilization (HCRU) among PWH. However, their effects among vulnerable sub-populations of PWH with coexisting mental health disorders (PWH/MHDs) in real-world settings are not well understood. This analysis examined the characteristics and HCRU patterns among PWH/MHDs who initiated MTRs vs STRs in a US Medicaid population. Methods A retrospective analysis of treatment-naïve Medicaid PWH/MHDs (based on claims for MHD-related diagnosis or treatments) using Anlitiks All Payor Claims database from 01/01/16-06/30/23 was conducted. The study included MTR or STR initiators (i.e., MTR/STR initiation date=index date) with ≥12-months pre- and post-index continuous enrollment. Baseline characteristics and post-index all-cause HCRU outcomes (PWH/MHD with ≥1 inpatient (IP) hospitalization, outpatient (OP) visits, emergency department (ED) visits, office visits, and other visits) were described using Chi-square, t-tests and Wilcoxon rank-sum tests as appropriate. HCRU outcomes were assessed using multivariate logistic regression models and reported as adjusted odds ratios (aOR) and 95% confidence intervals (CI). Results Among PWH/MHDs, MTR initiators (n=7,874) vs. STR initiators (n=46,024) were younger (43.6 vs. 47.2 years; p&amp;lt; 0.05), more likely to be female (64.3% vs. 53.6%; p&amp;lt; 0.05), and more likely to use substances (32.1% vs 29.4%; p&amp;lt; 0.05). MTR initiators had significantly higher aOR for: IP hospitalizations (1.49; CI:1.41-1.56), ER visits (1.38; CI: 1.31-1.44), OP visits (1.19; 1.44-1.26), and other visits (1.19; 1.44-1.26) compared to STR initiators. However, MTR initiators had significantly lower aOR (0.94; 0.89-0.99) for office visits compared to STR initiators. Conclusion This analysis indicates that PWH with MHDs in the Medicaid population are more likely to have higher HCRU while taking MTR compared to STR. The analysis also highlights that PWH with MHDs may be the underserved population who may benefit from receiving more tailored and simplified ART regimens. Disclosures Megan Chen, MSPH, Gilead Sciences, Inc.: Honoraria|Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Private Company) Mary J. Christoph, PhD, MPH, AstraZeneca: Advisor/Consultant|AstraZeneca: Former employee|AstraZeneca: Stocks/Bonds (Private Company)|Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Private Company) Seojin Park, PharmD, MS, Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Public Company) Woodie Zachry, RPh, PhD, Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Public Company) Amy Weinberg, DNP, MS, Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Private Company) Cassidy Trom, PharmD, AAHIVE, Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Private Company) Joshua Gruber, PhD MPH, Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Public Company) Krithika Rajagopalan, PhD, Gilead Sciences, Inc.: Advisor/Consultant

Association between vitamin D levels and preserved ratio impaired spirometry: an investigation of mediating roles of systemic inflammation and metabolic indicators

BackgroundPreserved ratio impaired spirometry (PRISm) represents an abnormal lung function state distinct from traditional chronic obstructive pulmonary disease, characterized by unique clinical and epidemiological features. PRISm has been associated with various health issues, including an increased risk of metabolic disorders and cardiovascular diseases. Vitamin D, known for its anti-inflammatory, immunomodulatory, and antioxidant properties, may play a role in reducing the risk of PRISm. This study aims to investigate the relationship between vitamin D levels and PRISm, including the mediating effects of systemic inflammation markers and metabolic indicators in a population of U.S. adults.MethodsThis cross-sectional study analyzed data from 17,333 participants from the U.S. National Health and Nutrition Examination Survey, including 1,577 individuals with PRISm and 15,756 without. Baseline characteristics were assessed, and multivariate logistic regression models were employed to examine the relationship between vitamin D and PRISm. Mediation analysis was conducted to explore potential mediating roles of systemic immune-inflammation index (SII), triglyceride-glucose (TyG) index, and bilirubin. Nonlinear relationships were assessed using restricted cubic spline (RCS) models.ResultsThe PRISm group had lower median vitamin D levels and distinct inflammatory and metabolic profiles compared to the non-PRISm group. Multivariate analysis confirmed an inverse association between vitamin D levels and PRISm (adjusted OR: 0.989, 95% CI: 0.984–0.994, p &amp;lt; 0.001). RCS analysis showed a nonlinear protective effect of vitamin D, with risk stabilizing at levels above 50 nmol/mL. Mediation analysis highlighted bilirubin as a positive mediator (ACME = −4.11 × 10−5, p &amp;lt; 0.001), while TyG demonstrated a suppressive mediation effect (ACME = 2.68 × 10−5, p &amp;lt; 0.001). SII did not show significant mediation.ConclusionElevated vitamin D levels are linked to a lower risk of PRISm, with bilirubin potentially acting as a mediator in this protective relationship. This underscores the clinical significance of maintaining sufficient vitamin D levels to promote lung health and mitigate the prevalence of PRISm among U.S. adults. Further research is warranted to investigate personalized vitamin D supplementation strategies as a potential preventive approach.

P-1577. Healthcare utilization, antibiotic spectrum index, and outcomes associated with complicated urinary tract infections in the United States

Abstract Background Despite a recent increase in the burden of complicated urinary tract infections (cUTI), contemporary data on healthcare utilization, outcomes and antimicrobial use related to cUTIs are lacking. We describe healthcare utilization, inpatient antibiotic use, and mortality associated with cUTI across a nationwide US hospital network. Methods This cohort study included inpatients aged ≥18 years with cUTI (using ICD-10 diagnostic codes) from 240 hospitals in the Premier Healthcare Claims Database between January 2016 – June 2020. Demographics, clinical characteristics, antibiotic use, and healthcare utilization measures were evaluated. In addition to antibiotic days of therapy, we calculated daily average Antibiotic Spectrum Index (ASI) which measures the spectrum of antimicrobial action based on number of organisms susceptible to that drug (total = 14 organism categories, e.g. ASI of penicillin is 2 while meropenem is 10, validated by Gerber et. al, PMID: 28560946). Primary outcome of inpatient mortality was assessed in a multivariable logistic regression model. Results In this cohort of 16,011 inpatients with cUTI, median age was 67 years (IQR 54- 77], 52.6% (N=8419) were female and 76.1% (N=12181) were white (Table 1). Over two thirds of patients with cUTI required intensive care unit care, while over 25% were bacteremic and required vasopressors. Median duration of antimicrobial therapy was 11 days [IQR: 7, 18] and median daily ASI was 10.40 [IQR: 7.80, 13.87]. Inpatient mortality was 6.4% and 30 day readmission rates were 17.7%. On multivariable analysis, significant risk factors for inpatient mortality in patients with cUTI included increasing age, with highest risk over 80 years of age (adjusted odds ratio (aOR) 3.25 (2.50 - 4.23); higher Charleston’s comorbidity index (aOR 1.05 (1.04 - 1.06)); admission from skilled nursing facility (aOR 1.39 (1.11 - 1.76) and higher ASI (aOR 1.05 (1.04 - 1.05, Table 2)). Conclusion In our cohort of 240 US hospitals, older adults and men experienced more than half of inpatient cUTIs. A large proportion of cUTIs were associated with high severity of illness requiring higher acuity of care. Older age, more comorbidities, and higher ASI were associated with increased mortality in patients with cUTI. Disclosures Sonali Advani, MBBS, MPH, FIDSA, Biomerieux: Advisor/Consultant|GSK: Advisor/Consultant|Locus Biosciences: Advisor/Consultant|Sysmex America: Advisor/Consultant Charles Scales, MD MSHS, BMS: Grant/Research Support|Exelixis: Grant/Research Support|Flume Catheter: Grant/Research Support|Lilac Therapeutics: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support

P-195. Clinical Clostridioides difficile Diagnostic Test Types and Results are Associated with the Likelihood of Recovering C. difficile in Stool Cultures

Abstract Background Active Clostridioides difficile infection (CDI) surveillance is conducted by the U.S. CDC’s Emerging Infections Program (EIP) and includes collection of a convenience sample of stool specimens from C. difficile positive cases. Accurate molecular epidemiology relies on recovering C. difficile from clinical specimens. We sought to determine whether CDI diagnostic testing approach was associated with the likelihood of culturing C. difficile from stool.Table 1.Characteristics of stool specimens collected from Clostridioides difficile positive stool specimens identified through Emerging Infections Program surveillance in Colorado and Georgia, January 2020 through December 2022 Methods We performed a cross-sectional study of the recovery of C. difficile from C. difficile positive stools collected from 1/2020 – 12/2022 from the Colorado and Georgia EIP sites. Stools were collected and stored per site protocols (i.e. Cary-Blair transport medium [CBTM] or fresh stool), frozen, and cultured at a reference laboratory. Multivariable logistic regression models were constructed to determine the adjusted odds ratio (aOR) for key variables in relationship to C. difficile recovery. A separate semi-quantitative experiment evaluating the impact of CBTM on recovery was conducted by placing stools in which C. difficile had been recovered into CBTM vs. phosphate-buffered saline (PBS).Table 2.Multivariable logistic regression models for Clostridioides difficile recovery from C. difficile positive stool specimens identified through Emerging Infections Program surveillance in Colorado and Georgia, January 2020 through December 2022 Results C. difficile was cultured from 1569 of 1921 stools (81.7%, Table 1). Semi-quantitative experiments revealed that CBTM had no impact on C. difficile recovery. Recovery of C. difficile from stool cultures was less likely among cases in which C. difficile was detected: 1) by multiplex PCR (aOR 0.45, 95% confidence interval [CI]: 0.32-0.62); 2) with a negative toxin enzyme immunoassay (EIA) (aOR 0.12, 95% CI: 0.06-0.22); and 3) by a PCR-only testing strategy (aOR 0.24, 95% CI: 0.12-0.45). Among 1056 cases with known toxin EIA test results, C. difficile recovery was less likely when C. difficile detection was associated with a multiplex PCR and in those with a negative toxin EIA (Table 2). Conclusion The ability to culture C. difficile from stool specimens was reduced when C. difficile was detected with a multiplex PCR, a PCR-only testing strategy, or with negative toxin EIA results. These findings can be used to maximize the yield of surveillance stool submission and culture protocols, thereby enhancing the ability to generate robust molecular epidemiology data to inform prevention and control efforts. Disclosures Andrew M. Skinner, MD, BioK plus: Advisor/Consultant|Ferring Pharmaceuticals: Advisor/Consultant|Recursion pharmaceutical: Advisor/Consultant Stuart Johnson, M.D., Acurx Pharmaceuticals: Advisor/Consultant|Bio-K Plus International: Advisor/Consultant|Ferring Phamraceuticals: Advisor/Consultant Dale N. Gerding, MD, AstraZeneca: Advisor/Consultant|Destiny Pharma: Advisor/Consultant|Destiny Pharma: Licensed IP to Destiny|Sebela: Advisor/Consultant|Sebela: Licensed IP

P-857. Serratia Bacteremia: Risk Factors, Complications and Outcomes

Abstract Background Previously considered a rare opportunistic pathogen, Serratia is now an emerging cause of bacteremia. However, the demographics and outcomes of patients with Serratia bacteremia remain poorly understood. We thus compared the risk factors and outcomes of patients with Serratia bacteremia relative to other Enterobacterales species in a prospectively ascertained cohort of hospitalized patients. Rates of device infection in patients with medical devices. Rates of device infection in patients with medical devices stratified by device type. P values ≤0.05 are considered statistically significant and indicated (*). Methods Patients with gram-negative bacteremia (GNB) were prospectively enrolled from 2002-2021 at Duke University. Clinical characteristics and outcomes were compared among patients with bacteremia due to Serratia and other Enterobacterales. Multivariable logistic regression models were used to determine features independently associated with outcomes. Risk factors associated with device-associated infection. Risk factors associated with device-associated infection. The multivariable models of factors associated with underlying device infection in patients with any medical device (A) and only cardiac devices (B) and gram-negative bacteremia are shown. P values ≤0.05 are considered statistically significant and indicated (*). Results Among 2676 patients with GNB, 173 (6.5%) had Serratia bacteremia. Patients with Serratia bacteremia, relative to GNB caused by other Enterobacterales, were more likely to have a medical device (59% vs 35.6%; P&amp;lt; 0.001), device-associated infection (42.2% vs. 21.3%, P&amp;lt; 0.001), and persistent bacteremia (23.2% vs. 12.9%; P&amp;lt; 0.001). Among all patients with a medical device (n = 993; 37.1%), Serratia was associated with an increased risk of any device infection in an adjusted model (odds ratio (OR) 2.031; 95% confidence interval (CI), 1.234-3.343). The risk for device infection was highest among patients with cardiac devices (OR 3.947, 95% CI 1.449-10.751). Conclusion Compared to patients with GNB due to other Enterobacterales, patients with Serratia bacteremia were more likely to have a device infection in general, a cardiac device-associated infection in particular, and persistent bacteremia. Disclosures Antonella Castagna, MD, Bristol-Myers Squibb: Advisor/Consultant|Gilead Sciences, Inc.: Advisor/Consultant|Gilead Sciences, Inc.: Grant/Research Support|Gilead Sciences, Inc.: Honoraria|Janssen: Advisor/Consultant|Janssen: Grant/Research Support|Janssen: Honoraria|Merck Sharp &amp; Dohme: Advisor/Consultant|Merck Sharp &amp; Dohme: Grant/Research Support|Merck Sharp &amp; Dohme: Honoraria|ViiV Healthcare: Advisor/Consultant|ViiV Healthcare: Grant/Research Support|ViiV Healthcare: Honoraria Vance G. Fowler, MD, MHS, Affinergy: Advisor/Consultant|ArcBio: Stocks/Bonds (Private Company)|Armata: Advisor/Consultant|Astra Zeneca: Advisor/Consultant|Astra Zeneca: Grant/Research Support|Basilea: Advisor/Consultant|Basilea: Grant/Research Support|ContraFect: Advisor/Consultant|ContraFect: Grant/Research Support|Debiopharm: Advisor/Consultant|Destiny: Advisor/Consultant|EDE: Grant/Research Support|Genentech: Advisor/Consultant|Genentech: Grant/Research Support|GSK: Advisor/Consultant|Janssen: Advisor/Consultant|Karius: Grant/Research Support|MedImmune: Grant/Research Support|Merck: Grant/Research Support|sepsis diagnostics: Patent pending|UptoDate: Royalties|Valanbuio: Stocks/Bonds (Private Company)|Valanbuio: Stocks/Bonds (Private Company) Joshua T. Thaden, MD, PhD, National Institutes of Health K08 AI171183 (Thaden): Grant/Research Support Stacey Maskarinec, MD, PHD, National Institutes of Health K23 HL159275 (Maskarinec): Grant/Research Support

P-836. Non-Beta Lactam Agents for Definitive Treatment of Ampicillin-Susceptible Enterococcus Bacteremia: A Single Center Experience

Abstract Background Enterococcus bacteremia (EB) is a serious infection with high morbidity and mortality. While anti-enterococcal beta-lactams (BL) remain the mainstay of therapy against ampicillin-susceptible (AS) EB, non-beta-lactam (NBL) antimicrobial agents are also used to treat ASEB. Few studies evaluate NBL use for definitive therapy of ASEB. CONSORT flow diagram of patients included in study. Methods A single-center retrospective study identified all ASEB episodes between 1/1/2016-12/31/2021 (Figure 1). Patient, microbiological, infection, treatment and outcomes were compared between those who received NBL versus BL for ASEB. Multivariable logistic regression analysis was used to determine factors associated with NBL use. Baseline characteristics of patients treated with non-beta-lactam vs beta-lactam for definitive therapy for ampicillin-susceptible Enterococcus bacteremia. Results 158 episodes of ASEB in 153 patients were included (Table 1). 43 episodes (27%) were treated with NBL for definitive therapy. Factors associated with NBL therapy were younger age (58 vs 66 years old, p=0.02), reported history of any penicillin allergy (42% vs 9%, p&amp;lt; 0.01) and serious penicillin allergy (14% vs 1%, p&amp;lt; 0.01), history of cancer (37% vs 17%, p=0.01), end-stage renal disease (ESRD; 23% vs 3%, p&amp;lt; 0.01), unknown source of bacteremia (24% vs 8%, p&amp;lt; 0.01), polymicrobial bacteremia (40% vs 16%, p&amp;lt; 0.01), lack of metastatic foci of infection (12% vs 31%, p=0.02), and lack of endocarditis (7 vs 23%, p=0.02). Combination therapy was used in 23% of those treated with BL therapy compared to no patients receiving NBL therapy (p&amp;lt; 0.01). For NBL vs BL therapy, there was no difference between all-cause 30-day mortality, all-cause 90-day mortality, or 30-day relapse rate. In a multivariable logistic regression model (Table 2), NBL therapy was more likely in those with: younger age (AOR 0.95, p=0.001), any penicillin allergy (AOR 5.76, p=0.001), history of cancer (AOR 5.23, p=0.001), ESRD (AOR 11.70, p=0), and polymicrobial bacteremia (AOR 4.20, p=0.001). Factors associated with use of non-beta-lactam antibiotic for definitive therapy of ampicillin-susceptible Enterococcus bacteremia: multivariable analysis. Conclusion NBL was used as definitive treatment in 27% of ASEB. Penicillin allergy, access and dosing for patients on hemodialysis, younger host, and polymicrobial infection are factors associated with NBL use. This real-life experience suggests NBL can be successfully used to treat non-severe ASEB. Further studies are needed to determine the efficacy and stewardship implications of NBL use for ASEB. Disclosures All Authors: No reported disclosures

P-1889. Penicillin Allergy and Its Impact on Clinical Outcomes in OPAT Patients: A Retrospective Cohort Study

Abstract Background 10% of the U.S. population is labeled as allergic to penicillin, with higher rates among women and older adults. These individuals often experience worse clinical outcomes. Despite the extensive use of Outpatient Parenteral Antimicrobial Therapy (OPAT), data on the prevalence of penicillin allergy in this population and its impact on clinical outcomes are scarce. Our study aims to address this knowledge gap by assessing rates of penicillin allergy in OPAT patients and its associations with OPAT-related clinical outcomes. Table 1 Comparison of characteristics and complications among OPAT patients considering penicillin allergy status Methods We conducted a retrospective cohort study at Tufts Medical Center, including all patients aged ≥18 years discharged on OPAT between April 2022 and October 2022. Data on demographics, penicillin allergy status, complications, and outcomes were extracted through chart reviews. The primary outcomes were: (1) rates of penicillin allergy, and (2) association between penicillin allergy and OPAT complication rate (line- or antibiotic-related), OPAT extension, 30-day ED visits, and readmission rates. We used a multivariable logistic regression model to examine these associations, adjusting for age, sex, race, ethnicity, and Charlson comorbidity index. Two-sided p values were considered statistically significant at .05. Table 2 Association of documented penicillin allergy and complications related to OPAT Results A total of 231 patients received OPAT; 39 (17.9%) had documented penicillin allergy. Females and white patients had higher rates of penicillin allergy compared to their counterparts; 24.4% vs 12.4% and 19.1% vs 9.4%, respectively (Table 1). In the final multivariable logistic regression model, penicillin allergy status was not associated with OPAT extension (adjusted odds ratios[aOR] 0.83; 95% confidence interval[CI] 0.36-1.89), OPAT-related complications (aOR 1.04; 95%CI 0.42-2.57), 30-day ED visits (aOR 0.38, 95%CI 0.05-3.13), and 30-day readmissions (aOR 0.24; 95%CI 0.03-1.87) (Table 2). Conclusion Our findings suggest that the rates of PCN allergy were higher than in hospital settings (∼15%), but these do not significantly influence the OPAT clinical outcomes. However, neither group met the required 248 subjects to reliably detect a 10% increase in complication rates, limiting the significance of the findings. Further research with a larger sample size is needed to validate these findings. Disclosures Shira Doron, MD, Medtronic: Expert Testimony|Sunovion: Advisor/Consultant|Vertex: Speaker

The effect of environmental hypothermia on survival in isolated blunt traumatic brain injury.

Environmental hypothermia increases mortality in patients with major trauma, however the impact of exposure hypothermia on outcomes in isolated traumatic brain injury (TBI) is under-explored in literature. The aim of this study is to determine the relationship between environmental hypothermia and survival in patients with isolated blunt TBI. We analyzed data from the Trauma Quality Improvement Program database. We included patients who were ≥15 years of age, had an abbreviated injury scale (AIS) ≥1 for the head/neck body region, an arrival Glasgow Coma Scale (GCS) of <14, an AIS of 0 for all other body regions, and a blunt mechanism. We defined hypothermia as <35 degrees Celsius. From 2020 to 2022, there were 16,697 patient encounters that met inclusion for this analysis. There were 670 (4%) patient encounters that met our definition of hypothermia. Hypothermic patients had lower unadjusted survival at 24 hours (79% versus 92%) and throughout their hospital stay (47% versus 77%, all p<0.001). In our multivariable logistic regression model, after adjusting for age, sex, arrival GCS, arrival shock index, mechanism of injury, and imaging findings, hypothermia was associated with lower survival at 24 hours (OR 0.59, 0.48-0.74) and lower total in-hospital survival (OR 0.44, 0.36-0.53). Environmental hypothermia is associated with increased mortality at 24 hours and at hospital discharge in patients with isolated blunt TBI. Further investigation is needed to identify optimal treatment strategies for TBI patients with hypothermia and to determine whether hypothermia prevention decreases mortality.

P-1958. Impact of COVID-19 on Acute Diverticulitis: Evidence of United States Hospitals in 2020

Abstract Background Acute diverticulitis, a prevalent gastrointestinal condition, frequently necessitates hospitalization and is associated with potential adverse in-hospital outcomes. Recent data showed the detrimental effects of COVID-19 infection on acute diverticulitis, particularly in patients with severe COVID-19 infections. However, limited information exists on the specific impacts of COVID-19 infection in patients hospitalized for acute diverticulitis. Methods We analyzed the 2020 U.S. National Inpatient Sample (NIS) to investigate the effects of COVID-19 infection on cases primarily admitted due to acute diverticulitis. Participants aged 18 and above were identified using relevant ICD-10 CM codes. Adjusted odds ratios (aORs) for specified outcomes were calculated through multivariable logistic and linear regression analyses. The primary outcome was inpatient mortality, with secondary outcomes including system-based complications. Statistical significance was established at a P value of 0.05. Results We identified 167,170 patients with a primary discharge diagnosis of acute pancreatitis. The mean age was 60.1 years; 56.8% were female. Caucasians accounted for the majority, followed by Hispanics. Of these, 0.90% (1,504/167,170) had a concurrent diagnosis of COVID-19 infection. In a survey multivariable logistic and linear regression model adjusting for patient and hospital factors, COVID-19 infection was associated with higher in-hospital mortality (aOR 8.43; 95% CI 4.32, 16.42, P &amp;lt; 0.001), prolonged length of stay (β LOS 2.02; 95% CI 1.27, 2.77, P &amp;lt; 0.001) and increased hospitalization charge ( β charge 17,813.27; 95% CI 4,080, 31,546, P &amp;lt; 0.001), We observed non-significant, but increased, risks of shock, acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), and mechanical ventilation in COVID-19 positive patients. Conclusion In conclusion, our study revealed that COVID-19 infection is associated with higher in-hospital mortality, prolonged hospital stays, and increased hospitalization charges in patients diagnosed with acute diverticulitis. Future longitudinal studies are warranted to comprehensively assess the long-term health sequelae in this population. Disclosures All Authors: No reported disclosures

P-1906. Early COVID-19 and Severity of Subsequent Omicron Infection in Ontario, Canada

Abstract Background As SARS-CoV-2 evolves, assessing changes in COVID-19 severity over time, and the impact of prior infection on repeat infection, is important. We determined whether developing COVID-19 early in the pandemic was associated with reduced severity of subsequent infection with Omicron sub-lineages. Methods We evaluated COVID-19 severity among patients infected during the Omicron wave. Severity was measured in 3 ways:(1) an ordinal measure combining activities of daily living (ADL) and presence of fever,(2) healthcare required (yes/no),(3) an ordinal measure of illness duration. We compared these outcomes in a study of age and time-period matched cohorts in Toronto, Canada: one with symptomatic COVID-19 between Mar 1 &amp; Sep 30/2020 ('early COVID-19') and another who did not test positive for SARS-CoV-2 during the same period. Participants completed baseline, then biweekly surveys to identify SARS-CoV-2 infection episodes from Jan 2020 to Jan 2023. Multivariable binary and ordinal logistic regression models were used to construct ORs and 95% CI for impact of early COVID-19 on severity, adjusted for social/demographic characteristics, comorbidities, COVID-19 vaccination status, and time from early COVID-19 to first Omicron infection. Results Of 261 participants with COVID-19 due to Omicron (Table 1), 177 had early COVID-19 at a median of 26 months prior. In adjusted analyses, those with early COVID-19 occurring &amp;lt; 24 months prior to their Omicron infection had lower odds of having severe Omicron-related illness; OR 0.35 (95%CI 0.15-0.80); with non-significant lower odds of requirement for healthcare (OR 0.49,95%CI 0.14-1.8) and illness duration (OR 0.80, 95%CI 0.32-2.0) (Table 2). Immunocompromise was associated with more severe illness based on all 3 outcomes; other non-immunocompromising comorbidities were associated with requiring healthcare and longer illness duration, and females reported longer illness duration (Table 2). Conclusion Developing COVID-19 early in the pandemic was associated with reduced severity of first Omicron infection if it occurred &amp;lt; 24 months later. Immunocompromise and the presence of other underlying comorbidities were associated with increased severity, and women reported longer duration of illness. Disclosures Moe H. Kyaw, PhD, Pfizer: Employee Catherine Martin, PhD, Pfizer: employee|Pfizer: Stocks/Bonds (Private Company) Maria Major, B.Sc., M.P.H., Pfizer: Employee Samira Mubareka, MD, Pfizer: Grant/Research Support Srinivas Valluri, PhD, Pfizer: Employee John M. McLaughlin, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Allison McGeer, MD, AstraZeneca: Honoraria|GSK: Honoraria|Merck: Honoraria|Moderna: Honoraria|Novavax: Honoraria|Pfizer: Grant/Research Support|Pfizer: Honoraria|Roche: Honoraria|Seqirus: Grant/Research Support|Seqirus: Honoraria