bluuebunny/crossref_metadata_2025_split huggingface dataset:
63. PK-RNN-V: A Deep Learning Model for Vancomycin Therapeutic Drug Monitoring using Electronic Health Record Data
Authors: Masayuki Nigo , Tran Hong Thoai Nga , Xie Ziqian , Feng Han , Bekhet Laila , Hongyu Miao , Zhi Degui 
Published: December 2021

Abstract

Background
Therapeutic drug monitoring (TDM) for vancomycin (VAN) with Bayesian models is recommended by national guidelines. However, limited data incorporating the models may hurt the performance. Our aim is to develop a novel deep learning-based pharmacokinetic model for vancomycin (PK-RNN-V) using electronic medical records (EHRs) data to achieve more accurate and personalized predictions for VAN levels.

Methods
EHR data were retrospectively retrieved from Memorial Hermann Hospital System, comprising 14 hospitals in the greater Houston area. All patients who received VAN and had any VAN levels were eligible. Patients receiving hemodialysis and extracorporeal membrane oxygenation were excluded. Demographic data, vital signs, diagnostic codes, concomitant medications, VAN administration, and laboratory data were preprocessed as longitudinal data. VAN infusion, VAN level measurement, or each hospital day were the time steps for the models. The dataset was splited 70:15:15 for training, validation, and test sets. Our PK-RNN-V model predicted individual patient volume distribution (v) and VAN elimination (k) at each time step using an irregular timesteps GRU model. To compare, Bayesian models were developed from publicly available models, and tuned to feedback the first VAN level to update the v and k. (VTDM)

Results
A total of 12,258 patients with 195,140 encounters were identified from Aug, 2019 and March, 2020. After exclusion of 6,775 patients, 5,483 patients with 8,689 encounters were included. Table 1 summarized the characteristics of patients included in our study. 55,336 doses of VAN were administered with a median dosage of 1.0 gm. VAN levels were measured 18,588 times at various timings. The median VAN level was 14.7 mcg/mL Table 2 described the performance of our models and VTDM models. Our model exhibited better performance compared to VTDM model (RMSE: 5.64 vs. 6.57, respectively). Figure 1 shows example prediction curves of VAN levels from each model.

Conclusion
PK-RNN-V model is a novel approach to predict patient PK and VAN levels. Our results revealed promising performance of this model. Our model can take a wide range of real-world patient data into the model. Further studies are warranted for external validations and model optimizations.

Disclosures
All Authors: No reported disclosures
90. Impact of Infection Control Assessment and Response (ICAR) Visit on Candida auris Colonization Rates at Seven Long Term Acute Care Hospitals (LTACH) in Los Angeles County
Authors: Bhurtyal Kiran , Nguyen Jennifer , Clarke Anthony , OYong Kelsey , Bhaurla Sandeep , Takiguchi Eric , Baldwin Leslie , Rubin Zachary 
Published: December 2021

Abstract

Background
Public health authorities often use Infection Control Assessment and Response (ICAR) visits during Candida auris (C. auris) outbreak investigation to identify facility-level infection prevention and control (IPC) practice gaps and make recommendations to address those gaps. As an adjunct to ICAR visit, point prevalence surveys (PPS) provide an objective measure to determine if IPC recommendations are implemented. Because they require significant public health resources to perform, we evaluated the impact of ICAR visits on C. auris colonization rates.

Methods
PPS were conducted at seven long-term acute-care hospitals (LTACH) with C. auris outbreaks in Los Angeles County from July 2020 to May 2021. Skin swabs collected at PPS were tested for C. auris colonization by PCR technique. Pre-ICAR PPS results were compared with the average of two serial post-ICAR PPS results using repeated measures ANOVA test. Linear regression was used to estimate associations between individual ICAR domains and C. auris colonization.

Results
54 PPS were conducted at seven LTACHs with at least one ICAR visit made for every two PPS. On average, PPS were conducted 14 days (range 1-15 days) before and 10 days (range 4-33 days) after an ICAR visit. PPS positive rates with ICAR visit dates for each LTACH are shown in figure 1. Overall, ICAR visits were associated with a significant decrease (p=0.035) in the average of the positive rates in two serial post-ICAR PPS. When individual domain (hand hygiene, contact precautions, and environmental disinfection) of ICAR tool was analyzed, only adherence to environmental disinfection was significantly associated (p=0.038) with decrease in C. auris colonization rates. There was a moderate negative correlation (R2 = 0.26, β= -0.33) between environmental disinfection adherence and the magnitude of decrease in the colonization rates across all LTACHs (Figure 2).
Figure 1

Figure 2

Conclusion
ICAR visits were found to be significantly associated with a decrease in the average PPS positive rate on serial PPS. Parts of the ICAR tool that assessed environmental disinfection at the facility seemed most correlated with decrease in C. auris colonization rate. Streamlining the ICAR process to focus on the most impactful parts of ICAR tool may be a more efficient intervention to control C. auris outbreaks.

Disclosures
All Authors: No reported disclosures
817. Appropriate Sites for the Active Surveillance of Carbapenemase-producing Enterobacteriaceae
Authors: Park Joung Ha , Choi Hye-Suk , Yang Hyejin , Lee Hyun-Ju , Kwak Sun Hee , Kim Eun Ok , Chong Yong Pil , Choi Sang-Ho , Lee Sang-Oh , Kim Yang Soo , Sung Heungsup , Kim Mi-Na , Kim Sung-Han , Jung Jiwon 
Published: December 2021

Abstract

Background
Active surveillance tests for carbapenemase-producing Enterobacteriaceae (CPE) are recommended in patients showing risk factors for colonization by these bacteria. There are limited data however on whether surveillance tests for anatomic sites other than the stool would be useful to detect CPE colonization, and we investigated this in our present study.

Methods
Retrospective analysis was performed on cases at our tertiary care hospital during a 5-year period. The study patients with CPE colonization had been admitted to our surgical intensive care unit (SICU) or sub-ICU for liver transplantation in this period and undergone surveillance tests for both the stool and other sites. Patients were grouped as stool CPE negative (but which included CPE positive cases from initial sputum and other site tests) or positive.

Results
Among the total study cohort of 158 patients, 138 (87.3%) were included in the stool CPE positive group and the remaining 20 (12.7%) in the stool CPE negative group. While the sensitivity of CPE surveillance testing of the stool was 87.3% (95% CI 81.1-92.1), the sensitivity when combining stool and sputum samples was 93.7% (88.7-96.9). The transmission rates were similar for patients showing CPE positivity in the stool, sputum and other sites, at 4.8% (27/557), 4.7% (3/64), and 6.7% (1/15), respectively (p = 0.95).

Conclusion
The sensitivity of CPE detection in a stool sample is suboptimal for ruling out CPE colonization and the transmission rates are similar between stool-positive or -negative cases. Combining surveillance of the stool with other sites may be needed for detecting CPE.

Disclosures
All Authors: No reported disclosures
824. Analysis of Comorbidities and Use of Co-medications in 28,089 HIV-positive Patients: A Nationwide Cohort Study From 2009 to 2019 in Japan
Authors: Naito Toshio , Suzuki Mai , Fukushima Shinichi , Yuda Mayumi , Fukui Nobuyuki , Tsukamoto Shotaro , Fujibayashi Kazutoshi , Goto-Hirano Keiko , Kuwatsuru Ryohei 
Published: December 2021

Abstract

Background
Comorbidities are associated with a high burden of disease in human immunodeficiency virus (HIV)- positive patients. The objective was to investigate the prevalence of chronic comorbidities and the use of co-medications in HIV-positive patients in Japan.

Methods
This longitudinal cohort study retrospectively analyzed clinical information from HIV-positive patients using antiretroviral therapy (ART) between April 2009 and April 2019. Demographic characteristics, numbers and types of chronic comorbidities and numbers and types of co-medications, were described by age groups. This is the first report to analyze comorbidities and the polypharmacy of all patients in the cross-sectional National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), which contains data on the largest number of HIV-positive patients in Japan, available to date.

Results
Overall, 28,089 HIV-positive patients (male 91·9%) who used ART were identified. About 40% of 28,089 patients had at least one chronic comorbidity. The number of acquired immunodeficiency syndrome (AIDS)-defining cancers and non-AIDS-defining cancers in this Japanese cohort was 2,432 (8·7%) and 2,485 (8·8%), respectively. The incidence of AIDS-defining cancers was 6·4% for non-Hodgkin lymphoma and 2·5% for Kaposi’s sarcoma, with bronchus or lung cancer being the most common of the non-AIDS-defining cancers. Syphilis was the most common infection (47·2%). The cumulative burden of vascular disease and AIDS-free cancer increased with age. The most common therapeutic categories of co-medications were systemic antibacterials (42%) and antacids, antiflatulents and antiulcerants (38·8%). Most of the patients used at least one co-medication (71·4%), and the numbers of co-medications used were greater in the older age groups.

Conclusion
The burden of chronic comorbidities and co-medication were found to be greater in older than younger patients, among 28,089 HIV-positive patients in a nationwide study in Japan. This finding suggests the need to identify elderly persons living with HIV and to appropriately manage their HIV and comorbidities.

Disclosures
All Authors: No reported disclosures
843. Targeted HIV Testing for Patients Hospitalized for COVID-19
Authors: Virata Michael D , Villanueva Merceditas , Miceli Janet 
Published: December 2021

Abstract

Background
SARS-CoV-2 causes a severe respiratory illness known as COVID-19. Treatment options in the early portion of the COVID-19 pandemic included the use of antiretroviral agents i.e. protease inhibitors (PIs) such as lopinavir (LPV) that had been shown to have activity against the main proteases of SARS-CoV-2 in vitro but with very limited clinical data. Prior to the use of PIs, HIV testing would be indicated to ensure that patients who were not previously diagnosed with HIV would start appropriate HIV treatment. In this unique situation, HIV testing would be utilized not based on traditional HIV risk factors.

Methods
We performed a retrospective search from a specific systems database of patients admitted to Yale-New Haven Health System (YNHHS) with a diagnosis of COVID-19 infection. We identified a subset of patients who were HIV tested. Most were done prior to initiating PI treatment. Demographics, comorbidity scores and specific underlying conditions were also tabulated. We performed Kruskal Wallis and Chi-Squared analysis to test for significance between HIV- and HIV+ patients.

Results
The total no. of patients admitted to the YNHHS with COVID-19 infection between the period from January 6, 2020 to January 6, 2021 was 5776. A cohort 964 (16.7%) patients were screened for HIV. Much of the testing occurred in the early COVID periods (Figure 1) when PIs were considered as part of the treatment algorithm. Sixty-seven (0.07%) patients tested HIV+ with 3 (0.003%) being newly diagnosed (Fig 2). Compared to HIV- patients, HIV+ were more likely to be identified as Black, with higher mean Elixhauser Comorbidity scores and significant associations with conditions such as hypertension, pulmonary disease, complicated diabetes, liver disease, renal failure and depression (Table 1). These co-morbidities have been correlated with higher risk of hospitalization for people living with HIV (PWH).
Figure 2. COVID Admission and HIV Status

The graph represents HIV testing results over the entire study period.
Table 1. Demographics and Comorbidites

Represents demographics and comorbidities of HIV- & HIV+ patients
Figure 1. COVID Admissions and HIV Testing

COVID admissions over time and the performance of HIV testing

Conclusion
This is one of the first reports on targeted HIV testing for patients not using identifiable traditional HIV risk factors who were admitted to a large healthcare system for COVID19 infections. The percentage of newly HIV diagnosed patients from this cohort was considered to be &lt; known HIV infection rates for our population. The majority of PWH were already established in care prior to their COVID19 diagnosis.

Disclosures
All Authors: No reported disclosures
845. Impact of the COVID-19 Pandemic on Routine HIV Screening in an Emergency Department
Authors: Aguilera Elizabeth A , Rodriguez Gilhen , Del Bianco Gabriela P , Heresi Gloria , Murphy James , Prater Samuel 
Published: December 2021

Abstract

Background
The Emergency Department (ED) at Memorial Hermann Hospital (MHH) - Texas Medical Center (TMC), Houston, Texas has a long established screening program targeted at detection of HIV infections. The impact of the COVID-19 pandemic on this screening program is unknown.

Methods
The Routine HIV screening program includes opt-out testing of all adults 18 years and older with Glasgow score &gt; 9. HIV 4th generation Ag/Ab screening, with reflex to Gennius confirmatory tests are used. Pre-pandemic (March 2019 to February 2020) to Pandemic period (March 2020 to February 2021) intervals were compared.

Results
72,929 patients visited MHH_ED during the pre-pandemic period and 57,128 in the pandemic period, a 22% decline. The number of patients tested for HIV pre-pandemic was 9433 and 6718 pandemic, a 29% decline. When the pandemic year was parsed into first and last 6 months interval and compared to similar intervals in the year pre pandemic, 39% followed by 16% declines in HIV testing were found. In total, 354 patients were HIV positives, 209, (59%) in the pre-pandemic and 145 (41%) in the pandemic period.The reduction in new HIV infections found was directly proportional to the decline in patients visiting the MHH-ED where the percent of patients HIV positive was constant across intervals (2.21% vs 2.26%). Demographic and outcome characteristics were constant across the compared intervals.

Conclusion
The COVID -19 pandemic reduced detection of new HIV infections by screening in direct proportion to the reduction in MHH-ED patient visits. The impact of COVID-19 pandemic decreased with duration of the pandemic.

Disclosures
All Authors: No reported disclosures
850. Reasons for not Using PrEP and Actions that May Facilitate PrEP Uptake in Ontario and British Columbia, Canada
Authors: Espinosa Oscar Javier Pico , Hull Mark , Lachowsky Nathan , Hall David , Mohammed Saira , Fisher Karla , Grace Daniel , Gaspar Mark , Truong Robinson , Mitterni Leo , Harding Matthew , MacPherson Paul , Woodward Kevin , Rayek Simon , Peters Eric , Jollimore Jody , Kilduff Marshall , Maxwell John , Greene Warren , Durrant Garfield , Arkell Camille , Cordeiro Tyllin , Tan Darrell 
Published: December 2021

Abstract

Background
HIV Pre-exposure prophylaxis (PrEP) is an underutilized intervention to prevent HIV infection in Canada. Known barriers to PrEP uptake include lack of awareness, low HIV risk perception, side effects, PrEP not being publicly funded (which is the case in Ontario) and stigma. We aimed to identify barriers to PrEP use and actions that may facilitate PrEP uptake in Ontario and British Columbia.

Methods
Gay, bisexual and other men who have sex with men 19 years or older living in Ontario and British Columbia, Canada, answered a survey between July 2019 and August 2020. Participants who met Canadian PrEP guideline criteria for PrEP and not already using PrEP indicated which barriers were relevant to them and which actions would make them more likely to start PrEP. We used descriptive statistics and tested differences between Ontario and British Columbia using Chi-square tests for proportions and t-tests or Wilcoxon rank-sum tests for continuous variables.

Results
Of 1527 survey responses, 260 (184 in Ontario and 76 in British Columbia) who were never PrEP users and met criteria for PrEP were included. In Ontario, the most common barriers were affordability (43%) and concern about side effects (42%). In British Columbia, the most common reasons were concern about side effects (41%) and not feeling at high enough risk (36%). In Ontario, the actions that would most likely encourage the respondent to start PrEP were short waiting time (63%), the healthcare provider informing about their HIV risk being higher than perceived (62%) and a written step-by-step guide (60%). In British Columbia, the actions that would most likely encourage the respondent to start PrEP were short waiting time (68%), people speaking publicly about PrEP (68%) and their healthcare provider counselling about: their HIV risk being higher than perceived (64%), side effects of PrEP (64%) and about how PrEP works (62%).
Table. Top reasons for not using PrEP and top actions that might influence the decision to start PrEP stratified by province. (n= 184 in Ontario, n= 76 in British Columbia).

Conclusion
Concern about side effects and not feeling at high enough risk were common barriers. Short waiting times may increase PrEP uptake. In Ontario, the findings suggested lack of affordability. In British Columbia, actions involving healthcare providers were valued.

Disclosures
Kevin Woodward, MD FRCPC, Gilead (Independent Contractor) Darrell Tan, MD PhD, Abbvie (Grant/Research Support)Gilead (Grant/Research Support)GlaxoSmithKline (Scientific Research Study Investigator)ViiV Healthcare (Grant/Research Support)
857. Discussion and Initiation of HIV Pre-exposure Prophylaxis Were Rare Following Diagnoses of Sexually Transmitted Infections among Veterans
Authors: Kobayashi Takaaki , Van Epps Puja , Maier Marissa , Beste Lauren , Beck Brice , Alexander Bruce , Ohl Michael 
Published: December 2021

Abstract

Background
Healthcare encounters for the diagnosis and treatment of sexually transmitted infections (STIs) are common and represent a window of opportunity to discuss and initiate HIV pre-exposure prophylaxis (PrEP). Little is known about how frequently PrEP is discussed and initiated in association with encounters for STIs.

Methods
We conducted a retrospective cohort and nested case control study in the national Veterans Administration (VA) healthcare system to determine the frequency of PrEP discussion and initiation in association with clinical encounters for bacterial STIs (i.e. early syphilis, gonorrhea, and chlamydia). We used administrative data to identify patients with a first STI based on ICD 9 / 10 codes from January 2013–December 2018 , excluding patients with prior HIV diagnosis or PrEP use, or STI diagnosed in context of a visit to initiate PrEP (Figure 1). We used pharmacy data to determine the frequency of PrEP initiation within 90 days of the encounter for STI in this cohort. In the case control study, we matched 90 PrEP starters to 180 non-starters by day of STI diagnosis and reviewed chart notes from the STI diagnosis encounter to determine frequency of documentation of sexual history taking and PrEP discussions among subsequent PrEP initiators and non-initiators.

Results
We identified 23,312 patients with a first STI, of whom 90 (0.4%) started PrEP within 90 days. Adjusting for age, PrEP initiation was associated with urban residence (OR=5.0, 95Cl 1.8–13.4), White compared to Black race (OR=1.7, 95 Cl 1.1–2.8), and syphilis diagnosis (OR = 7.4, 95 Cl 4.7–11.6, table 1). Chart review revealed that discussion of PrEP was rare among people with STIs who did not subsequently start PrEP (1.1%, 95 CI 0.1–4.0, table 2). PrEP initiation was associated with documentation of any sexual history (80.0% of initiators vs. 51.0% of non-initiators, p &lt; 0.01) and discussion of PrEP (52.2% vs. 1.1%, p &lt; 0.01) during the initial STI diagnosis encounter.

Figure 1. Study flow chart
Table 1. Characteristics of patients with a first healthcare encounter with an STI diagnosis, by PrEP initiation within 90 days of encounter. N= 23,312

Table 2. Chart review findings from case control study. Ninety people who initiated PrEP (i.e., “cases”) were randomly matched to 180 who did not initiate PrEP (i.e., “controls”) by date of STI.

Conclusion
Discussion and initiation of PrEP were rare in association with healthcare encounters for STIs. Not all individuals with STIs will benefit from starting PrEP, but interventions are needed to improve low rates of sexual history-taking and discussion of PrEP during healthcare encounters for STIs.

Disclosures
Bruce Alexander, PharmD, Bruce Alexander Consulting (Independent Contractor)
869. A Qualitative Review of Social Barriers Impeding Retention in HIV Care at a Ryan White Clinic
Authors: Florakis Eleni , Johanna Smith , Kennedy Alyssa , Spacek Lisa A 
Published: December 2021

Abstract

Background
Ending the HIV Epidemic: A Plan for America aims to decrease new HIV diagnoses 75% by 2025 and 90% by 2030. To achieve this, we identified patients unable to achieve viral suppression with social-behavioral needs deemed ‘high-hanging fruit.’ Via extensive outreach efforts and creation of shared problem solving, we pursued the goals of rapid and effective treatment leading to viral suppression and prevention of HIV transmission. We (1) exhausted all avenues of outreach to re-engage patients in HIV care and (2) identified personal or social characteristics related to difficulties in visit retention and achieving viral suppression.

Methods
Of 446 Ryan White-eligible patients seen in an urban, academic medical center, 46 did not achieve and/or maintain viral suppression, and qualified for the study. We conducted a mixed methods survey comprised of both multiple choice and open-ended questions to ascertain what barriers patients face to continuous engagement in care and to achieving viral suppression. We developed a re-engagement outreach cycle which included: text messages and phone calls, electronic messages via patient portal or email, phone call to pharmacy to cross-check contact information, outreach to patients’ emergency contact, and sending a letter by mail.

Results
Of 46 participants, 32 were reached and 14 were not found. Sixteen re-engaged in care and of these, 14 completed the survey (see Figure). Those who completed the survey noted the following barriers to care: poor mental health, financial issues, problems committing to an appointment due to work/family/transportation, and COVID-19. Out of all 46 participants, the 14 who were not found had an overall a higher index of chaos. This index of chaos included, but was not limited to: homelessness, IV drug use, domestic violence, and stigma.
Outreach to re-engage in HIV care

A. Participants in study, B. Outreach outcomes, C. Common survey themes

Conclusion
Intensive efforts are required to re-engage patients, counsel on adherence, and achieve viral suppression. The reasons for lack of engagement in care are real and challenging. Multiple cycles of continuous outreach serve to establish trust, address barriers, and connect to HIV care.

Disclosures
All Authors: No reported disclosures