Centralizing Telehealth Test-to-Treat Through a Regional Clinical Contact Center: A Veterans Health Administration Pilot.

Background: This project describes a Veterans Health Administration telehealth pilot to facilitate COVID-19 oral antiviral treatment as part of the national test-to-treat (T2T) strategy. The pilot was operationalized for two pilot VA medical centers by the regional clinical contact center (CCC) for a Veteran Integrated Service Network, which offers multiple services through several virtual modalities. Methods: Nurse triage and medical provider evaluation templates were developed for the CCC to standardize clinical interventions with veteran callers reporting positive home COVID-19 test results. When veterans were determined eligible and consented to treatment with an emergency use authorization (EUA) antiviral medication, CCC providers used secure direct messaging for synchronous communication with local pharmacy services to facilitate adjudication and dispensing. Templates for pharmacy documentation and primary care follow-up monitoring were also developed and disseminated. Results: In total, 198 veterans (mean age 65 years, 89% male, 88% non-Hispanic White) were evaluated through telehealth by regional CCC providers using the T2T process and 96% were prescribed an antiviral medication. Primary care follow-up occurred in 86% of cases, a median of 3 days after the telehealth evaluation. The 30-day all-cause hospitalization rate was 1.5% and there were no deaths within 30 days of treatment initiation. Conclusions: Veterans Integrated Service Network's CCC telehealth triage and evaluation processes enabled safe EUA-compliant care delivery, improved evaluator experience and efficiency, and augmented existing EUA processes in place by front-line pharmacy and primary care teams.

Implications of Electronic Consultations for Clinician Communication and Relationships: A Qualitative Study.

BACKGROUND: Strong relationships and effective communication between clinicians support care coordination and contribute to care quality. As a new mechanism of clinician communication, electronic consultations (e-consults) may have downstream effects on care provision and coordination. OBJECTIVE: The objective of this study was to understand primary care providers' and specialists' perspectives on how e-consults affect communication and relationships between clinicians. RESEARCH DESIGN: Qualitative study using thematic analysis of semistructured interviews. SUBJECTS: Six of 8 sites in the VISN 1 (Veterans Integrated Service Network) in New England were chosen, based on variation in organization and received e-consult volume. Seventy-three respondents, including 60 clinicians in primary care and 3 high-volume specialties (cardiology, pulmonology, and neurology) and 13 clinical leaders at the site and VISN level, were recruited. MEASURES: Participants' perspectives on the role and impact of e-consults on communication and relationships between clinicians. RESULTS: Clinicians identified 3 types of e-consults' social affordances: (1) e-consults were praised for allowing specialist advice to be more grounded in patient data and well-documented, but concerns about potential legal liability and increased transparency of communication to patients and others were also noted; (2) e-consults were perceived as an imperfect modality for iterative communication, especially for complex conversations requiring shared deliberation; (3) e-consults were understood as a factor influencing clinician relationships, but clinicians disagreed on whether e-consults promote or undermine relationship building. CONCLUSIONS: Clinicians have diverse concerns about the implications of e-consults for communication and relationships. Our findings may inform efforts to expand and improve the use of e-consults in diverse health care settings.

Front-Line innovation: Rapid implementation of a nurse-driven protocol for care of outpatients with COVID-19.

AIMS AND OBJECTIVES: Our objective was to rapidly adapt and scale a registered nurse-driven Coordinated Transitional Care (C-TraC) programme to provide intensive home monitoring and optimise care for outpatient Veterans with COVID-19 in a large urban Unites States healthcare system. BACKGROUND: Our diffuse primary care network had no existing model of care by which to provide coordinated result tracking and monitoring of outpatients with COVID-19. DESIGN: Quality improvement implementation project. METHODS: We used the Replicating Effective Programs model to guide implementation, iterative Plan-Do-Study-Act cycles and SQUIRE reporting guidelines. Two transitional care registered nurses, and a geriatrician medical director developed a protocol that included detailed initial assessment, overnight delivery of monitoring equipment and phone-based follow-up tailored to risk level and symptom severity. We tripled programme capacity in time for the surge of cases by training Primary Care registered nurses. RESULTS: Between 23 March and 15 May 2020, 120 Veterans with COVID-19 were enrolled for outpatient monitoring; over one-third were aged 65 years or older, and 70% had medical conditions associated with poor COVID-19 outcomes. All Veterans received an initial call within a few hours of the laboratory reporting positive results. The mean length of follow-up was 8.1 days, with an average of 4.2 nurse and 1.3 physician or advanced practice clinician contacts per patient. The majority (85%) were managed entirely in the outpatient setting. After the surge, the model was disseminated to individual primary care teams through educational sessions. CONCLUSION: A model based on experienced registered nurses can provide comprehensive, effective and sustainable outpatient monitoring to high-risk populations with COVID-19.

What Is the Primary Driver of Preoperative Vancomycin Use? It's Not Methicillin-resistant Staphylococcus aureus-or Allergy.

Factors driving vancomycin surgical prophylaxis are poorly understood. In a national Veterans Affairs cohort with manually validated data, surgical specialty (cardiac, orthopedics) and perception of high facility methicillin-resistant Staphylococcus aureus (MRSA) prevalence-not MRSA colonization-were the primary drivers of prescribing. A ß-lactam allergy was the second most common reason. These data may inform perioperative stewardship.

How Testing Drives Treatment in Asymptomatic Patients: Level of Pyuria Directly Predicts Probability of Antimicrobial Prescribing.

BACKGROUND: Urinalysis is a readily available test often used for screening. Pyuria is a common finding in asymptomatic patients; however, it is unknown how often identification of pyuria in the absence of confirmatory cultures leads to antimicrobial prescribing. The objective of this study was to measure the association between pyuria and antimicrobial initiation during the perioperative period and assess harms versus benefits of treatment. METHODS: A retrospective cohort of preoperative patients within the national healthcare system during the period 1 October 2008-30 September 2013 who had a urinalysis performed during the 30-day preoperative period was created; patients with positive urine cultures were excluded. The primary exposure was pyuria on preoperative urinalysis. The primary outcome was antimicrobial initiation. Secondary outcomes included postoperative surgical site (SSI), urinary tract (UTI), and Clostridioides difficile infections. Trend and logistic regression analyses were performed. RESULTS: Among 41 373 patients, 3617 had pyuria. 887 (24.5%) patients with pyuria received antimicrobials versus 1918 (5.1%) patients without pyuria. As the degree of pyuria increased, the odds of receiving antimicrobials also increased linearly (low, 14.7%; moderate, 24.0%; high pyuria, 37.4%). Preoperative pyuria was associated with postoperative C. difficile infections (aOR, 1.7; 95% CI, 1.2-2.4); risk was higher in patients who received antimicrobials (aOR, 2.4; 1.7-3.4). Pyuria was not associated with SSI but was associated with increases in UTI after orthopedic and vascular procedures; this risk was not mitigated by antimicrobial therapy. CONCLUSIONS: Urine screening during the preoperative period is a low-value intervention that increases antimicrobial exposure but does not improve postoperative outcomes.

Clostridium difficile Screening for Colonization During an Outbreak Setting.

A rapidly deployed ward-based screen and isolate initiative for Clostridium difficile carriers during an outbreak averted 5 of 10 expected hospital-acquired infections without identified harms. Each infection avoided required screening 197 and isolating 4.4 patients. Targeted C. difficile screening resulted in outbreak mitigation.

Electronic Consultations (E-consults): Advancing Infectious Disease Care in a Large Veterans Affairs Healthcare System.

The impact of e-consults on total consultative services was evaluated. After implementing infectious diseases e-consults within an electronically integrated healthcare system, consultation volume increased. As compared with face-to-face consultations, e-consults were more often related to antimicrobial guidance and were requested by off-site providers. E-consults increased the breadth and volume of total consults.

Risk of surgical site infection, acute kidney injury, and Clostridium difficile infection following antibiotic prophylaxis with vancomycin plus a beta-lactam versus either drug alone: A national propensity-score-adjusted retrospective cohort study.

BACKGROUND: The optimal regimen for perioperative antimicrobial prophylaxis is controversial. Use of combination prophylaxis with a beta-lactam plus vancomycin is increasing; however, the relative risks and benefits associated with this strategy are unknown. Thus, we sought to compare postoperative outcomes following administration of 2 antimicrobials versus a single agent for the prevention of surgical site infections (SSIs). Potential harms associated with combination regimens, including acute kidney injury (AKI) and Clostridium difficile infection (CDI), were also considered. METHODS AND FINDINGS: Using a multicenter, national Veterans Affairs (VA) cohort, all patients who underwent cardiac, orthopedic joint replacement, vascular, colorectal, and hysterectomy procedures during the period from 1 October 2008 to 30 September 2013 and who received planned manual review of perioperative antimicrobial prophylaxis regimen and manual review for the 30-day incidence of SSI were included. Using a propensity-adjusted log-binomial regression model stratified by type of surgical procedure, the association between receipt of 2 antimicrobials (vancomycin plus a beta-lactam) versus either single agent alone (vancomycin or a beta-lactam) and SSI was evaluated. Measures of association were adjusted for age, diabetes, smoking, American Society of Anesthesiologists score, preoperative methicillin-resistant Staphylococcus aureus (MRSA) status, and receipt of mupirocin. The 7-day incidence of postoperative AKI and 90-day incidence of CDI were also measured. In all, 70,101 procedures (52,504 beta-lactam only, 5,089 vancomycin only, and 12,508 combination) with 2,466 (3.5%) SSIs from 109 medical centers were included. Among cardiac surgery patients, combination prophylaxis was associated with a lower incidence of SSI (66/6,953, 0.95%) than single-agent prophylaxis (190/12,834, 1.48%; crude risk ratio [RR] 0.64, 95% CI 0.49, 0.85; adjusted RR 0.61, 95% CI 0.46, 0.83). After adjusting for SSI risk, no association between receipt of combination prophylaxis and SSI was found for the other types of surgeries evaluated, including orthopedic joint replacement procedures. In MRSA-colonized patients undergoing cardiac surgery, SSI occurred in 8/346 (2.3%) patients who received combination prophylaxis versus 4/100 (4.0%) patients who received vancomycin alone (crude RR 0.58, 95% CI 0.18, 1.88). Among MRSA-negative and -unknown cardiac surgery patients, SSIs occurred in 58/6,607 (0.9%) patients receiving combination prophylaxis versus 146/10,215 (1.4%) patients who received a beta-lactam alone (crude RR 0.61, 95% CI 0.45, 0.83). Based on these associations, the number needed to treat to prevent 1 SSI in MRSA-colonized patients is estimated to be 53, compared to 176 in non-MRSA patients. CDI incidence was similar in both exposure groups. Across all types of surgical procedures, risk of AKI was increased in the combination antimicrobial prophylaxis group (2,971/12,508 [23.8%] receiving combination versus 1,058/5,089 [20.8%] receiving vancomycin alone versus 7,314/52,504 [13.9%] receiving beta-lactam alone). We found a significant association between absolute risk of AKI and receipt of combination regimens across all types of procedures. If the observed association is causal, the number needed to harm for severe AKI following cardiac surgery would be 167. The major limitation of our investigation is that it is an observational study in a predominantly male population, which may limit generalizability and lead to unmeasured confounding. CONCLUSIONS: There are benefits but also unintended consequences of antimicrobial and infection prevention strategies aimed at "getting to zero" healthcare-associated infections. In our study, combination prophylaxis was associated with both benefits (reduction in SSIs following cardiac surgical procedures) and harms (increase in postoperative AKI). In cardiac surgery patients, the difference in risk-benefit profile by MRSA status suggests that MRSA-screening-directed prophylaxis may optimize benefits while minimizing harms in this selected population. More information about long-term outcomes and patient and societal preferences regarding risk of SSI versus risk of AKI is needed to improve clinical decision-making.

Detecting the presence of an indwelling urinary catheter and urinary symptoms in hospitalized patients using natural language processing.

OBJECTIVE: To develop a natural language processing pipeline to extract positively asserted concepts related to the presence of an indwelling urinary catheter in hospitalized patients from the free text of the electronic medical note. The goal is to assist infection preventionists and other healthcare professionals in determining whether a patient has an indwelling urinary catheter when a catheter-associated urinary tract infection is suspected. Currently, data on indwelling urinary catheters is not consistently captured in the electronic medical record in structured format and thus cannot be reliably extracted for clinical and research purposes. MATERIALS AND METHODS: We developed a lexicon of terms related to indwelling urinary catheters and urinary symptoms based on domain knowledge, prior experience in the field, and review of medical notes. A reference standard of 1595 randomly selected documents from inpatient admissions was annotated by human reviewers to identify all positively and negatively asserted concepts related to indwelling urinary catheters. We trained a natural language processing pipeline based on the V3NLP framework using 1050 documents and tested on 545 documents to determine agreement with the human reference standard. Metrics reported are positive predictive value and recall. RESULTS: The lexicon contained 590 terms related to the presence of an indwelling urinary catheter in various categories including insertion, care, change, and removal of urinary catheters and 67 terms for urinary symptoms. Nursing notes were the most frequent inpatient note titles in the reference standard document corpus; these also yielded the highest number of positively asserted concepts with respect to urinary catheters. Comparing the performance of the natural language processing pipeline against the human reference standard, the overall recall was 75% and positive predictive value was 99% on the training set; on the testing set, the recall was 72% and positive predictive value was 98%. The performance on extracting urinary symptoms (including fever) was high with recall and precision greater than 90%. CONCLUSIONS: We have shown that it is possible to identify the presence of an indwelling urinary catheter and urinary symptoms from the free text of electronic medical notes from inpatients using natural language processing. These are two key steps in developing automated protocols to assist humans in large-scale review of patient charts for catheter-associated urinary tract infection. The challenges associated with extracting indwelling urinary catheter-related concepts also inform the design of electronic medical record templates to reliably and consistently capture data on indwelling urinary catheters.

Activity of Fosfomycin against Extended-Spectrum-ß-Lactamase-Producing Uropathogens in Patients in the Community and Hospitalized Patients.

Few oral antibiotics exist for the empirical treatment of extended-spectrum ß-lactamase (ESBL) urinary tract infections (UTI). In this study, we sought to determine the activity of fosfomycin against ESBL-producing uropathogens from patients at 3 Veterans Affairs (VA) facilities between 2010 and 2013. Among the ESBL uropathogens, 19.9% were fosfomycin resistant. Klebsiella species were more likely than Escherichia coli to be resistant (46% versus 4%; P < 0.001). Fosfomycin remains active against a majority of the ESBL uropathogens, although resistance among Klebsiella spp. was higher than that in previous reports.

Two Simple Rules for Improving the Accuracy of Empiric Treatment of Multidrug-Resistant Urinary Tract Infections.

The emergence of multidrug-resistant (MDR) uropathogens is making the treatment of urinary tract infections (UTIs) more challenging. We sought to evaluate the accuracy of empiric therapy for MDR UTIs and the utility of prior culture data in improving the accuracy of the therapy chosen. The electronic health records from three U.S. Department of Veterans Affairs facilities were retrospectively reviewed for the treatments used for MDR UTIs over 4 years. An MDR UTI was defined as an infection caused by a uropathogen resistant to three or more classes of drugs and identified by a clinician to require therapy. Previous data on culture results, antimicrobial use, and outcomes were captured from records from inpatient and outpatient settings. Among 126 patient episodes of MDR UTIs, the choices of empiric therapy against the index pathogen were accurate in 66 (52%) episodes. For the 95 patient episodes for which prior microbiologic data were available, when empiric therapy was concordant with the prior microbiologic data, the rate of accuracy of the treatment against the uropathogen improved from 32% to 76% (odds ratio, 6.9; 95% confidence interval, 2.7 to 17.1; P < 0.001). Genitourinary tract (GU)-directed agents (nitrofurantoin or sulfa agents) were equally as likely as broad-spectrum agents to be accurate (P = 0.3). Choosing an agent concordant with previous microbiologic data significantly increased the chance of accuracy of therapy for MDR UTIs, even if the previous uropathogen was a different species. Also, GU-directed or broad-spectrum therapy choices were equally likely to be accurate. The accuracy of empiric therapy could be improved by the use of these simple rules.

Comparative Effectiveness of Single versus Combination Antibiotic Prophylaxis for Infections after Transrectal Prostate Biopsy.

An increase in fluoroquinolone resistance and transrectal ultrasound-guided prostate (TRUS) biopsy infections has prompted the need for alternative effective antibiotic prophylaxis. We aimed to compare ciprofloxacin and other single-agent therapies to combination therapy for efficacy and adverse effects. Men who underwent a TRUS biopsy within the VA Boston health care system with documented receipt of prophylactic antibiotics periprocedure were eligible for inclusion. Postprocedure infections within 30 days were ascertained by chart review from electronic records, including any inpatient, outpatient, or urgent-care visits. Among 455 evaluable men over a 3-year period, there were 25 infections (5.49%), with sepsis occurring in 2.4%, urinary tract infections (UTI) in 1.54%, and bacteremia in 0.44% of patients. Escherichia coli was the most common urine (89%) and blood (92%) pathogen, with fluoroquinolone resistance rates of 88% and 91%, respectively. Ciprofloxacin alone was associated with significantly more infections than ciprofloxacin plus an additional agent (P = 0.014). Intramuscular gentamicin alone was also significantly associated with a higher infection rate obtained with all other regimens (P = 0.004). Any single-agent regimen, including ciprofloxacin, ceftriaxone, or gentamicin, was associated with significantly higher infection rates than any combination regimen (odds ratio [OR], 4; 95% confidence interval [CI], 1.47, 10.85; P = 0.004). Diabetes, immunosuppressive condition or medication, hospitalization within the previous year, and UTI within the previous 6 months were not associated with infection risk. Clostridium difficile infections were similar. These findings suggest that ciprofloxacin, ceftriaxone, and gentamicin alone are inferior to a combination regimen. Institutions with high failure rates of prophylaxis for TRUS biopsies should consider combination regimens derived from their local data.

Evidence from whole genome sequencing of aerosol transmission of SARS-CoV-2 almost 5 hours after hospital room turnover.

Experimental evidence suggests that Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) remains viable within aerosols with a half-life of approximately 3 hours; however, it remains unclear how long airborne SARS-CoV-2 can transmit infection. Whole genome sequencing during an outbreak suggested in-room transmission of SARS-CoV-2 to two patients admitted nearly 2 and 5 hours, respectively, after discharge of an asymptomatic infected patient. These findings suggest that airborne SARS-CoV-2 may transmit infection for over 4 hours, even in a hospital setting.

Propensity Score-Weighted Analysis of Postoperative Infection in Patients With and Without Preoperative Urine Culture.

Importance: Although recent guidelines recommend against performance of preoperative urine culture before nongenitourinary surgery, many clinicians still order preoperative urine cultures and prescribe antibiotics for treatment of asymptomatic bacteriuria in an effort to reduce infection risk. Objective: To assess the association between preoperative urine culture testing and postoperative urinary tract infection (UTI) or surgical site infection (SSI), independent of baseline patient characteristics or type of surgery. Design, Setting, and Participants: This cohort study analyzed surgical procedures performed from January 1, 2017, to December 31, 2019, at any of 112 US Department of Veterans Affairs (VA) medical centers. The cohort comprised VA enrollees who underwent major elective noncardiac, nonurological operations. Machine learning and inverse probability of treatment weighting (IPTW) were used to balance the characteristics between those who did and did not undergo a urine culture. Data analyses were performed between January 2023 and January 2024. Exposures: Performance of urine culture within 30 days prior to surgery. Main Outcomes and Measures: The 2 main outcomes were UTI and SSI occurring within 30 days after surgery. Weighted logistic regression was used to estimate odds ratios (ORs) for postoperative infection based on treatment status. Results: A total of 250 389 VA enrollees who underwent 288 858 surgical procedures were included, with 88.9% (256 753) of surgical procedures received by males and 48.9% (141 340) received by patients 65 years or older. Baseline characteristics were well balanced among treatment groups after applying IPTW weights. Preoperative urine culture was performed for 10.5% of surgical procedures (30 384 of 288 858). The IPTW analysis found that preoperative urine culture was not associated with SSI (adjusted OR [AOR], 0.99; 95% CI, 0.90-1.10) or postoperative UTI (AOR, 1.18; 95% CI, 0.98-1.40). In analyses limited to orthopedic surgery and neurosurgery as a proxy for prosthetic implants, the adjusted risks for UTI and SSI were also not associated with preoperative urine culture performance. Conclusions and Relevance: This cohort study found no association between performance of a preoperative urine culture and lower risk of postoperative UTI or SSI. The results support the deimplementation of urine cultures and associated antibiotic treatment prior to surgery, even when using prosthetic implants.

Facilitators and Barriers to Verifying Penicillin Allergies in a Veteran Nursing Home Population.

BACKGROUND: Unconfirmed penicillin allergies are common and may contribute to adverse outcomes, especially in frail older patients. Evidence-based clinical pathways for evaluating penicillin allergies have been effectively and safely applied in selected settings, but not in nursing home populations. OBJECTIVE: To identify potential facilitators and barriers to implementing a strategy to verify penicillin allergies in Veterans Health Administration nursing homes, known as Community Living Centers (CLCs). METHODS: We conducted semistructured interviews with staff, patients, and family members at 1 CLC to assess their understanding of penicillin allergies and receptiveness to verifying the allergy. We also asked staff about the proposed allergy assessment strategy, including willingness to delabel by history and feasibility of performing oral challenges or skin testing on their unit. RESULTS: From 24 interviews (11 front-line staff, 4 leadership, 3 patients, 6 family members), we identified several facilitators or barriers. Staff recognized the importance of allergy verification and were willing to support and assist in implementing verification strategies. The CLC residents were willing to have their allergy status verified. However, some family members expressed reluctance to verifying their relative's allergy status owing to safety concerns. Front-line staff also expressed concern over having the necessary resources, including time and expertise, to implement the strategy. Staff suggested involving clinical pharmacists and educating staff, patients, and family members as ways to overcome these barriers. CONCLUSIONS: Concerns about safety and staff resources are important potential barriers to implementing verification strategies. Involvement of pharmacists and education of both staff and patients and family members will be important components of any successful intervention.

Understanding suboptimal e-consult requests: lessons from the VA.

OBJECTIVES: Electronic consultations, or e-consults, which are requests for specialist advice without direct patient interaction, are becoming increasingly common across health systems. We sought to identify clinicians' perspectives on the quality of e-consult requests that they send and receive. STUDY DESIGN: A qualitative research study at the US Department of Veterans Affairs (VA) New England Healthcare System. METHODS: We interviewed a total of 73 clinicians, including 38 specialists across 3 specialties (cardiology, neurology, pulmonology) and 35 primary care clinicians (PCCs), between March and June 2019. The interviews were analyzed using thematic analysis. RESULTS: VA specialists and PCCs generally agreed that e-consult requests should be focused and precise, not require lengthy chart review, and include adequate preliminary workup results. At the same time, specialists expressed frustration with what they perceived as suboptimal e-consult requests. Interviewees attributed this gap to 3 factors: limitations of the electronic health record user interface, divergence between PCCs and specialists in the areas of expertise, and organizational pressures on the 2 groups. CONCLUSIONS: VA clinicians' perspectives on suboptimal requests contain lessons that are broadly applicable to other health systems that seek to maximize the potential of e-consults to facilitate clinician collaboration and care coordination.

A Novel Informatics Tool to Detect Periprocedural Antibiotic Allergy Adverse Events for Near Real-time Surveillance to Support Audit and Feedback.

Importance: Standardized processes for identifying when allergic-type reactions occur and linking reactions to drug exposures are limited. Objective: To develop an informatics tool to improve detection of antibiotic allergic-type events. Design, Setting, and Participants: This retrospective cohort study was conducted from October 1, 2015, to September 30, 2019, with data analyzed between July 1, 2021, and January 31, 2022. The study was conducted across Veteran Affairs hospitals among patients who underwent cardiovascular implantable electronic device (CIED) procedures and received periprocedural antibiotic prophylaxis. The cohort was split into training and test cohorts, and cases were manually reviewed to determine presence of allergic-type reaction and its severity. Variables potentially indicative of allergic-type reactions were selected a priori and included allergies entered in the Veteran Affair's Allergy Reaction Tracking (ART) system (either historical [reported] or observed), allergy diagnosis codes, medications administered to treat allergic reactions, and text searches of clinical notes for keywords and phrases indicative of a potential allergic-type reaction. A model to detect allergic-type reaction events was iteratively developed on the training cohort and then applied to the test cohort. Algorithm test characteristics were assessed. Exposure: Preprocedural and postprocedural prophylactic antibiotic administration. Main Outcomes and Measures: Antibiotic allergic-type reactions. Results: The cohort of 36 344 patients included 34 703 CIED procedures with antibiotic exposures (mean [SD] age, 72 [10] years; 34 008 [98%] male patients); median duration of postprocedural prophylaxis was 4 days (IQR, 2-7 days; maximum, 45 days). The final algorithm included 7 variables: entries in the Veteran Affair's hospitals ART, either historic (odds ratio [OR], 42.37; 95% CI, 11.33-158.43) or observed (OR, 175.10; 95% CI, 44.84-683.76); PheCodes for "symptoms affecting skin" (OR, 8.49; 95% CI, 1.90-37.82), "urticaria" (OR, 7.01; 95% CI, 1.76-27.89), and "allergy or adverse event to an antibiotic" (OR, 11.84, 95% CI, 2.88-48.69); keyword detection in clinical notes (OR, 3.21; 95% CI, 1.27-8.08); and antihistamine administration alone or in combination (OR, 6.51; 95% CI, 1.90-22.30). In the final model, antibiotic allergic-type reactions were identified with an estimated probability of 30% or more; positive predictive value was 61% (95% CI, 45%-76%); and sensitivity was 87% (95% CI, 70%-96%). Conclusions and Relevance: In this retrospective cohort study of patients receiving periprocedural antibiotic prophylaxis, an algorithm with a high sensitivity to detect incident antibiotic allergic-type reactions that can be used to provide clinician feedback about antibiotic harms from unnecessarily prolonged antibiotic exposures was developed.