Outpatient Laboratory Tests Research Articles

Risk of clinical sequelae after the acute phase of SARS-CoV-2 infection: retrospective cohort study

ObjectiveTo evaluate the excess risk and relative hazards for developing incident clinical sequelae after the acute phase of SARS-CoV-2 infection in adults aged 18-65.DesignRetrospective cohort study.SettingThree merged data sources from...

SARS-CoV-2 seroprevalence, and IgG concentration and pseudovirus neutralising antibody titres after infection, compared by HIV status: a matched case-control observational study

BackgroundMost cohorts show similar or lower COVID-19 incidence among people living with HIV compared with the general population. However, incidence might be affected by lower testing rates among vulnerable populations. We aimed to compare SARS-CoV-2 IgG seroprevalence, disease severity, and neutralising antibody activity after infection among people with and without HIV receiving care in a county hospital system over a 3-month period.MethodsIn this matched case-control observational study, remnant serum samples were collected between Aug 1 and Oct 31, 2020, from all people living with HIV who underwent routine outpatient laboratory testing in a municipal health-care system (San Francisco General Hospital, CA, USA). Samples from people living with HIV were date of collection-matched (same day) and age-matched (±5 years) to samples from randomly selected adults (aged 18 years or older) without HIV receiving care for chronic conditions at the same hospital. We compared seroprevalence by HIV status via mixed-effects logistic regression models, accounting for the matched structure of the data (random effects for the matched group), adjusting for age, sex, race or ethnicity, and clinical factors (ie, history of cardiovascular or pulmonary disease, and type 2 diabetes). Severe COVID-19 was assessed in participants with past SARS-CoV-2 (IgG or PCR) infection by chart review and compared with multivariable mixed-effects logistic regression, adjusting for age and sex. SARS-CoV-2 IgG, neutralising antibody titres, and antibody avidity were measured in serum of participants with previous positive PCR tests and compared with multivariable mixed-effects models, adjusting for age, sex, and time since PCR-confirmed SARS-CoV-2 infection.Findings1138 samples from 955 people living with HIV and 1118 samples from 1062 people without HIV were tested. SARS-CoV-2 IgG seroprevalence was 3·7% (95% CI 2·4 to 5·0) among people with HIV compared with 7·4% (5·7 to 9·2) among people without HIV (adjusted odds ratio 0·50, 95% CI 0·30 to 0·83). Among 31 people with HIV and 70 people without HIV who had evidence of past infection, the odds of severe COVID-19 were 5·52 (95% CI 1·01 to 64·48) times higher among people living with HIV. Adjusting for time since PCR-confirmed infection, SARS-CoV-2 IgG concentrations were lower (percentage change −53%, 95% CI −4 to −76), pseudovirus neutralising antibody titres were lower (−67%, −25 to −86), and avidity was similar (7%, −73 to 87) among people living with HIV compared with those without HIV.InterpretationAlthough fewer infections were detected by SARS-CoV-2 IgG testing among people living with HIV than among those without HIV, people with HIV had more cases of severe COVID-19. Among people living with HIV with past SARS-CoV-2 infection, lower IgG concentrations and pseudovirus neutralising antibody titres might reflect a diminished serological response to infection, and the similar avidity could be driven by similar time since infection.FundingUS National Institute of Allergy and Infectious Diseases, US National Institutes of Health.

Perspectives of health care use and access to care for individuals living with inflammatory bowel disease in rural Canada.

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with no known cure. Management of IBD is complex and requires those with IBD to have lifelong interactions with the healthcare system. Individuals with IBD who live in rural areas are at risk of poorer health outcomes due to their limited access to care. This study examined healthcare utilization and access to care for rural adults with IBD. The research questions explored in this study were: What are the care experiences of healthcare providers (HCPs) and persons living with IBD in rural areas? What are the enablers and barriers to optimal IBD care in rural environments? What strategies are necessary to enhance care delivery for these individuals with IBD? This patient-oriented research initiative involved patient and family advisors as active and equal team members in decision-making throughout the project. This article reports on the qualitative findings of a larger mixed-methods study. The setting was one western Canadian province. Fourteen individuals with IBD living in rural areas and three HCPs working in rural areas participated. Interview data were analyzed using thematic analysis. Three themes were identified: communication, stressors and support systems, and coordination of care. Communication with and between HCPs was challenging due to the distance to access care. Participants described challenges related to rural HCPs' lack of IBD-related knowledge. Virtual communication, such as telehealth and phone clinics, was infrequently used yet highly recommended by participants. Individuals with IBD described various stressors and feelings of isolation while living in rural environments, and both participant groups described the need for additional formal and informal support systems to ease these stressors. Coordination of care was considered essential to optimal health outcomes, but individuals frequently experienced gaps in care. Lack of local services such as outpatient clinics, hospitals, laboratory testing, infusion clinics, and pharmacies meant individuals with IBD frequently had to travel to access care. Some participants reported bypassing existing local services, instead preferring the expedited, specialist care within larger centers. Most participants described challenges associated with living in rural areas and suggested health system improvements. Access to multidisciplinary care teams, including IBD physicians and nurses, psychologists, and dieticians, for individuals in rural areas is encouraged, as is the use of virtual care delivery options such as telehealth, online clinics, telephone clinics or advice lines, web-based video-conferencing, and email communication to increase access to care. Continued efforts to recruit and retain rural HCPs with knowledge of IBD are deemed necessary to provide continuity of care within rural environments. Strengthening formal and informal support systems and enhancing psychosocial supports in rural communities are warranted to ensure optimal wellbeing. Online strategies to provide individual and group education related to IBD are strongly recommended. Facilitating access to care in rural areas can increase disease remission, decrease direct and indirect care costs, and promote quality of life in individuals with IBD.

Economic burden of severe asthma in Turkey: a cost of illness study from payer perspective.

Objective. To estimate economic burden of severe asthma in Turkey from payer perspective based on expert panel opinion on practice patterns in clinical practice. Methods. This cost of illness study was based on identification of per patient annual direct medical costs for the management of sever easthma in Turkey from payer perspective. Average per patient direct medical cost was calculated based on cost items related to outpatient visits, laboratory and radiological tests, hospitalizations and interventions, drug treatment and equipment, and co-morbidities/complications. Results. Based on total annual per patient costs calculated for outpatient admission ($ 177.91), laboratory and radiological tests ($ 82.32), hospitalizations/interventions ($ 1,154.55), drug treatment/equipment ($ 2,289.63) and co-morbidities ($ 665.39) cost items, total per patient annual direct medical costrelated to management of severe asthma was calculated to be $ 4,369.76 from payer perspective. Drug treatment/equipment (52.4%) was the main cost driver in the management of severe asthma in Turkey, as followed by hospitalizations/interventions (26.4%) and co-morbidities (15.2%). Conclusions. In conclusion, our findings indicate that managing patients with severe asthma pose a considerable burden to health economics in Turkey, with medications as the main cost driver.

Seroprevalence, Neutralizing Antibody Titers Following Infection, and COVID-19 Disease Severity Differ Among People With and Without HIV

Background: Most cohorts show similar or lower COVID-19 incidence among people living with HIV (PLWH) compared to the general population. However, incidence may be impacted by lower testing rates among vulnerable populations. We compared SARS-CoV-2 IgG seroprevalence, disease severity, and neutralizing antibody activity after infection among people with and without HIV receiving care within a county hospital system over a three-month period.Methods: From August through October 2020, remnant serum samples were collected from all PLWH who underwent routine outpatient laboratory testing in a municipal healthcare system which houses a large HIV clinic. Patients with HIV were date-of-collection and age-matched (same day, +/- 5 years respectively) to adults without HIV. SARS-CoV-2 IgG and neutralizing antibody titers were measured in serum. Severe disease was assessed by chart review.Findings: Overall, 2,256 samples from 955 PLWH and 1062 people without HIV were tested. Among PLWH, the seroprevalence was 3.7% as compared to 7.4% among people without HIV (adjusted odds ratio (AOR) 0·48; 95% Confidence Interval (CI): 0·34; 0·71). Among those with evidence of prior infection (IgG or PCR), the odds of severe disease were more than 5-fold higher among PLWH (OR 5·13 95% CI: 1·05; 38·9). Among those with past infection, SARS-CoV-2 IgG levels were 45% lower among PLWH vs. those without HIV (95% CI: 22%; 61%); neutralizing antibody titers were 63% lower among PLWH (2%-78%).Interpretation: Among PLWH, there were approximately 50% lower odds of past SARS-CoV-2 infection, possibly due to greater non-pharmaceutical intervention adherence among a population with experience of the HIV epidemic. However, in spite of fewer infections, PLWH experienced more cases of severe disease. Among PLWH with past SARS-CoV-2 infection, lower neutralizing antibody titers were observed and may lead to increased risk of severe COVID-19 disease or reinfection. PLWH should be followed after vaccination to ensure they mount and maintain sufficient responses.Funding Statement: This work was funded by NIH/NIAID R01AI158013.Declaration of Interests: MAS, DVG, TJH, MG, and LBB report funding from the NIH during conduct of the study. DVG reports personal fees from Gilead Sciences outside the submitted work. All other authors have nothing to declare. Ethics Approval Statement: As only remnant samples were used, the University of California, San Francisco IRB did not require informed consent for study participation.The UCSF IRB # is 20-30387.

Post-Mrna Vaccination SARS-CoV-2 IGG Concentrations and Surrogate Virus Neutralization Response Compared by HIV Status and Type of Vaccine: A Matched Case-Control Observational Study

Background: Limited data is available on whether there are differences in the humoral response to mRNA SARS-CoV-2 vaccination by HIV status. We compared surrogate virus neutralization tests (sVNT) and anti-receptor-binding-domain (RBD) IgG concentrations by HIV status, as well as if responses differed by mRNA vaccine type. Methods: Remnant serum samples were collected during the month of May 2021 from all people living with HIV (PLWH) undergoing outpatient laboratory testing in a U.S. municipal health-care system. Samples from 100 PLWH were then matched on the same number of days following second mRNA vaccination, age (+/- 5 years), birth sex, and type of mRNA vaccine to samples from 100 adults receiving care for chronic conditions at the same hospital. Antibody responses were measured using a previously validated sVNT and anti-RBD IgG, with non-response defined as the limit of detection at <10 reciprocal titer and <10 relative fluorescent units respectively. Responses were compared by HIV status using mixed-effects models. Findings: In each matched group there were 13 women; 25 received the mRNA-1273 vaccine and 75 received the BNT162b2 vaccine. There were 2.43-fold higher odds of sVNT non-response among PLWH [95% confidence interval (CI)=1.09-5.39]. Although few individuals did not mount an anti-RBD IgG response (12 among PLWH vs. 5; p=0.08), continuous anti-RBD concentrations were 43% lower among PLWH (GMR 0.57; 95% CI=0.36-0.88). After adjusting for age, sex, and days post-second-vaccination, receipt of the BNT162b2 vs. mRNA-1273 vaccine was associated with 77% lower sVNT titers, each 100-cell increase in CD4+ T-cell count was associated with 22% higher titers (GMR 1.22; 95% CI=1.09-1.37), while unsuppressed RNA>200 copies/mL was associated with 89% lower titers (GMR 0.11; 95% CI=0.01-0.84). Interpretation: PLWH had lower than expected response to mRNA SARS-CoV-2 vaccines, particularly among those with low CD4+ T-cell counts, unsuppressed HIV RNA, and those who received the BNT162b2 vaccine. Funding: This research was supported by U.S. National Institute of Allergy and Infectious Diseases (NIAID) R01AI158013 (M.A.S. and M.G.), and U.S. NIAID P30AI027763 (M.G.) Declaration of Interest: DVG reports personal fees from Gilead Sciences outside the submitted work. All other authors declare no competing interests. Ethical Approval: As only remnant samples were used, the University of California, San Francisco IRB did not require informed consent for study participation. The UCSF IRB # is 20-30387.

1709. Influenza Surveillance in the U.S. Department of Veterans Affairs (VA): 2019-2020 Season

BackgroundVA conducts annual surveillance for seasonal influenza. VA’s large elderly population is at higher risk for influenza complications, including hospitalization and death. Herein we summarize VA’s 2019-20 national surveillance data for influenza activity and vaccinations.MethodsInfluenza telephone triage, influenza-like-illness (ILI) encounters and antiviral prescriptions plus outpatient visits, laboratory testing (antibody tests excluded), hospitalizations and deaths for influenza were obtained from VA data sources (9/29/19-5/16/20) and compared to prior seasons and national CDC FluView data. Influenza vaccinations were captured starting 8/1/2019. Vaccination rates were calculated based on VA users during the fiscal year.ResultsSurveillance metrics are presented (Table). ILI visits ranged from 0.9%-3.1% during the season. Influenza activity peaked during 2020 Weeks 6-7 and dropped rapidly beginning in Week 12, matching trends reported by CDC for influenza activity (Figure 1). Testing revealed 23,357 influenza positives out of 162,102 tests performed (14.4%). 17% of laboratory-confirmed influenza cases were hospitalized (compared to 23% during the prior season) with a median length of 3 days. Total influenza positives, telephone triage encounters, outpatient visits and antiviral use were higher than the prior season, whereas coded hospitalizations and deaths were fewer (Table, Figure 2).Table. VA Influenza Surveillance Measures, 2014-2015 through 2019-2020 Seasons. Figure 1. Comparison of select VA and CDC Influenza Indicators. Influenza positive laboratory tests and % positive (top) and influenza hospitalizations (bottom), by Season. Figure 2. Comparison of Key VA Influenza Indicators, by Season. ConclusionThe 2019-20 influenza season was of moderate severity when compared to prior seasons and continues to track well with national CDC data. Overall, vaccination levels have increased modestly and high-dose/adjuvanted vaccine administration increased from 6 to 26% of total vaccine given over the seasons evaluated. Influenza activity dropped precipitously after Week 12 even though testing for influenza remained high in the setting of COVID-19. This may have been influenced by widespread social distancing and masking measures adopted in response to COVID-19.Disclosures All Authors: No reported disclosures

Access to health care for patients with thalassaemia in Greece: a cross-sectional study.

The prevalence and clinical burden of beta-thalassaemia in Greece is high. Little information is available on the unmet needs of patients with beta-thalassaemia and barriers to access to care. This study investigated barriers that patients with transfusion-dependent beta-thalassaemia in Greece face when accessing care and the associations between socioeconomic factors and access to care. A cross-sectional study was conducted between November 2018 and January 2019. The sample consisted of 116 beta-thalassaemia patient-members of two Panhellenic patient associations for people with thalassaemia. All respondents were transfusion-dependent. The survey customized and used the Patient Access Partnership 5As of access tool to measure participants' access to health care services (subscales: accessibility, adequacy, affordability, appropriateness and availability). Data on their socioeconomic characteristics were also recorded. The association between the total score of each subscale and patient characteristics was examined using the Mann-Whitney or Kruskal-Wallis tests. Respondents considered inpatient services less adequate and appropriate, and outpatient services and laboratory tests less affordable. Outpatient services were also perceived as less available. Participants' income was statistically significantly associated with all the subscales except accessibility, and rural residence was significantly associated with all five subscales. Barriers in access to health care among beta-thalassaemia patients receiving transfusions still persist, especially for those who live far from transfusion centres and have lower incomes. It is important to understand and map current unmet medical and social needs of beta-thalassaemia patients in Greece, in order to design and implement a targeted health policy that can measurably improve patients' lives.

Inpatient-outpatient shared electronic health records: telemedicine and laboratory follow-up after hospital discharge.

Continuity of patient information across settings can improve transitions after hospital discharge, but outpatient clinicians often have limited access to complete information from recent hospitalizations. We examined whether providers' timely access to clinical information through shared inpatient-outpatient electronic health records (EHRs) was associated with follow-up visits, return emergency department (ED) visits, or readmissions after hospital discharge in patients with diabetes. Stepped-wedge observational study. As an integrated delivery system staggered implementation of a shared inpatient-outpatient EHR, we studied 241,510 hospital discharges in patients with diabetes (2005-2011), examining rates of outpatient follow-up office visits, telemedicine (phone visits and asynchronous secure messages), laboratory tests, and return ED visits or readmissions (as adverse events). We used multivariate logistic regression adjusting for time trends, patient characteristics, and medical center and accounting for patient clustering to calculate adjusted follow-up rates. For patients with diabetes, provider use of a shared inpatient-outpatient EHR was associated with a statistically significant shift toward follow-up delivered through a combination of telemedicine and outpatient laboratory tests, without a traditional in-person visit (from 22.9% with an outpatient-only EHR to 27.0% with a shared inpatient-outpatient EHR; P < .05). We found no statistically significant differences in 30-day return ED visits (odds ratio, 1.02; 95% CI, 0.96-1.09) or readmissions (odds ratio, 0.98; 95% CI, 0.91-1.06) with the shared EHR compared with the outpatient-only EHR. Real-time clinical information availability during transitions between health care settings, along with robust telemedicine access, may shift the method of care delivery without adversely affecting patient health outcomes. Efforts to expand interoperability and information exchange may support follow-up care efficiency.

Economic Burden of Pediatric Asthma in Turkey: A Cost of Illness Study from Payer Perspective.

To estimate economic burden of pediatric asthma in Turkey from payer perspective. This cost of illness study was based on identification of per patient annual direct medical costs for the management of pediatric asthma in Turkey from payer perspective. Average per patient direct medical cost was calculated based on cost items related to outpatient visits, laboratory and radiological tests, hospitalizations and interventions, drug treatment and equipment, and co-morbidities/complications. Based on total annual per patient costs calculated for outpatient admission ($113.14), laboratory-radiological tests ($35.94), hospitalizations ($725.92), drug treatment/equipment ($212.90) and co-morbidities/complications ($144.62) cost items, total per patient annual direct medical cost related to management of pediatric asthma was calculated to be $1,232.53 from payer perspective. Hospitalizations and interventions (58.9%) was the main cost driver. Direct cost for managing controlled and uncontrolled pediatric asthma were calculated to be $530.17 [key cost driver: drugs/equipment (40.0%)] and $1,023.16 [key cost driver: hospitalization/interventions (59.0%)], respectively. Our findings indicate that managing patients with pediatric asthma pose a considerable burden to health economics in Turkey, with hospitalizations identified as the main cost driver and two-fold cost increment in case of uncontrolled disease.

2313. Influenza and Respiratory Syncytial Virus (RSV) Surveillance in the US Department of Veterans Affairs (VA): 2018–2019 Season

BackgroundVA conducts ongoing surveillance for viral respiratory infections, notably influenza and more recently RSV. VA’s large elderly population is at higher risk for influenza and RSV complications, including hospitalization and death. Herein we summarize VA’s 2018–19 national surveillance data.MethodsInfluenza telephone triage, influenza-like-illness (ILI) encounters and antiviral prescriptions plus outpatient visits, laboratory testing (antibody tests excluded), hospitalizations and deaths for both influenza and RSV were obtained from VA data sources (9/30/18–3/31/19) and compared with prior seasons. Influenza vaccinations were captured starting 8/1/2018. Vaccination rates were calculated based on VA users during the fiscal year.ResultsSurveillance metrics are presented (Table, Figure). ILI visits ranged from 0.9%-3.3% during the season. RSV peaked earlier than influenza (Week 1 vs. Week 11). Testing revealed 1,674 RSV positives out of 31,404 tests performed (5.3%) and 15,052 influenza positives out of 105,760 tests performed (14.2%). We identified 22 cases of RSV and influenza co-infection (positive test results on the same date or within 3 days). 22% of laboratory-confirmed influenza cases were hospitalized (same proportion as the prior season) while 35% of RSV cases were hospitalized. Median length of stay was longer for RSV hospitalizations (4 days vs. 3 days for influenza).ConclusionThe 2018–2019 influenza season was less severe than the 2017–2018 season, and most like the 2016–2017 season. 2018–2019 saw relatively little Influenza B in VA patients, despite elevated activity into the spring. High-dose/adjuvanted vaccine administration increased over the seasons evaluated. RSV surveillance for 2018–2019 demonstrated an earlier peak in activity and the percentage of patients with laboratory-confirmed RSV who were hospitalized and died during their hospitalization was higher compared with influenza. Although fewer RSV tests were performed and testing practices were variable across VA facilities, the weekly trend aligned closely with influenza. Surveillance for both viruses is important in VA given their associated morbidity and mortality. Disclosures All authors: No reported disclosures.

The financial and time burden associated with phenylketonuria treatment in the United States

BackgroundPhenylketonuria (PKU) imposes a substantial burden on people living with the condition and their families. However, little is known about the time cost and financial burden of having PKU or caring for a child with the condition. Methods and findingsPrimary data were collected with a detailed cost and utilization survey. Primary outcomes included utilization and out-of-pocket costs of medical services, medical formula, and prescribed low-protein food consumption, as well as the time and perceived effort involved in following the PKU diet. Respondents were people living with PKU or parents of children with PKU identified through a state newborn screening program database. Secondary administrative claims data were also used to calculate mean total, insurer, and out-of-pocket payments in inpatient, outpatient (office visits, emergency room, and laboratory tests), and pharmacy settings for privately insured persons with PKU. Payments were calculated for sapropterin and for PKU formula.In primary data analysis (children n = 32, adults n = 52), annual out-of-pocket costs were highest for low-protein foods (child = $1651; adult = $967) compared with other categories of care. The time burden of PKU care was high; families reported spending more than 300 h per year shopping for and preparing special diet foods.In secondary data analysis, children 12–17 years old had the highest average medical expenditures ($54,147; n = 140) compared to children 0–11 years old ($19,057; n = 396) and adults 18 years and older ($40,705; n = 454). Medication costs were the largest contributor to medical costs, accounting for 61–81% of total costs across age groups. Sapropterin was the largest driver of medication costs, accounting for 85% of child medication costs and 92% of adult medication costs. ConclusionTreatment for PKU incurs a substantial time and cost burden on persons with PKU and their families. Estimated medical expenditures using claims data varied by age group, but sapropterin represented the largest cost for PKU treatment from a payer perspective across age groups.

Outcome of surgery in neck of femur fracture patients with poor pre-fracture mobility.

Hip fractures are common with a UK incidence of over 70,000 cases and total healthcare costs of over £2 billion per year. Mortality rates of 10% at 30 days and up to 30% at 1-year have been reported. We wanted to assess the outcome of hip fracture surgery in patients with reduced pre-fracture mobility as this has not been exclusively studied previously. We retrospectively reviewed 168 hip fracture patients with reduced pre-fracture mobility (wheelchair bound, bed bound, walking with 2 aids or a frame) who underwent hip fracture surgery at our institution between 2008 and 2013 using case notes, discharge letters, outpatient clinic letters and laboratory test results. Measured outcomes included 30-day renal, cardiac and respiratory morbidity as well as 30-day and 1-year mortality. Our study comprised 27% males and 73% females with a mean age of 82 years. The 30-day chest infection, acute renal failure and acute coronary syndrome rates were 26%, 7.7% and 4% respectively. In those patients who were either wheelchair or bed bound, 30-day and 1-year mortality rates were 11.8% and 52% respectively whereas in those who could mobilise with the help of 2 aids or frame, 30-day and 1-year mortality rates were 4.34% and 39.70% respectively. Our study highlighted increased 30-day and 1-year morbidity and mortality rates following hip fracture surgery with notable high rates of respiratory and renal complications in patients with reduced pre-fracture mobility. We would recommend pre- and postoperative optimisation with orthogeriatric review, chest physiotherapy and intravenous fluid hydration to reduce complication rates and improve morbidity and mortality.

Laboratory Diagnosis of HIV in the Outpatient Setting: One Hospital’s Perspective

Abstract Traditional methods for the diagnosis of human immunodeficiency virus types 1 and 2 (HIV-1, HIV-2) involve initial screening by an immunoassay followed by a specific method Western blot. However, Western blot is not sensitive compared to third-generation immunoassay, which detects both IgG and IgM antibodies against viral envelope proteins causing false-positive results. In addition, neither initial screening nor confirmatory Western blot is capable of detecting acute infection earlier in the disease process, when the virus is more adaptable and highly infectious. To detect both acute and established infection, Abbott Architect platform introduced a new fourth-generation antigen/antibody initial screening assay in 2013. Also, to reduce false-negative results from Western blot, an alternate method Bio-Rad multisport immunoassay was recommended by the Centers for Disease Control and Prevention (CDC) that has higher sensitivity and can differentiate HIV-1 and HIV-2 infections. In 2014, the CDC released updated recommendations for the laboratory diagnosis of HIV. The CDC diagnostic algorithm recommends an initial combination immunoassay that detects HIV-1 and HIV-2 antibodies, followed by supplemental testing with an immunoassay that differentiates HIV-1 and HIV-2 antibodies. Specimens reactive on the initial antigen/antibody immunoassay but nonreactive or indeterminate on the differentiation immunoassay should be followed by nucleic acid testing (NAT) for resolution of this discrepancy. The objective of our study was to review the effect of this updated testing algorithm on HIV testing results in the outpatient setting at Banner University Medical Center–Tucson in Tucson, Arizona. Our study utilized laboratory information system queries to retroactively review all outpatient HIV laboratory testing results obtained from 2013 to 2017. A total of 17,397 HIV-1/2 antigen/antibody immunoassays were performed during this time period. Of the initial antigen/antibody immunoassays, 1.1% were reactive (n = 183). Of these reactive tests, 85% were collected from individuals with established HIV infections (n = 155). HIV-1/HIV-2 antibody differentiation assays were performed on 175 patients, with 86% reactive (n = 150), 2.3% indeterminate (n = 4), and 12% nonreactive (n = 21). Acute HIV-1 infections (antigen/antibody immunoassay reactive, antibody differentiation immunoassay nonreactive or indeterminate, and NAT positive) accounted for 2.7% of patients with reactive initial antigen/antibody immunoassays and 0.03% of all patients screened for HIV infection with the initial antigen/antibody immunoassay (n = 5). Viral loads in the patients with acute HIV-1 infection ranged from 173,000 to &gt;10,000,000 copies/mL. No HIV-2 infections were identified in our patient population. Given that the previous CDC testing algorithm for HIV-1 failed to identify acute HIV-1 infections, our data, which confirm the ability of the current CDC algorithm to detect HIV-1 infections, represent important information for infectious disease practitioners, public health officials, and laboratory directors.

Treatment for human visceral leishmaniasis: a cost-effectiveness analysis for Brazil.

To estimate the cost-effectiveness of strategies for the treatment of VL in Brazil. Cost-effectiveness study comparing three therapeutic options: meglumine antimoniate (MA), liposomal amphotericin B (LAMB) and a combination of LAMB plus MA (LAMB plus MA), from public health system and societal perspectives. An analytical decision-making model was used to compare strategies for the following outcomes: early therapeutic failure avoided at 30days, days of hospitalisation avoided and VL cure at 180days. The efficacy and safety parameters of the drugs came from a randomised, open-label trial and the cost data came from a cost-of-illness study, both carried out in Brazil. For all outcomes analysed, the LAMB strategy was more effective. The MA strategy was inferior to the LAMB plus MA strategy for the outcomes early therapeutic failure avoided and cure. When only LAMB and MA were compared from a societal perspective, a cost of US$ 278.56 was estimated for each additional early therapeutic failure avoided, a cost of US$ 26.88 for each additional day of hospitalisation avoided and a cost of US$ 89.88 for each additional case of cured VL, for the LAMB strategy vs. MA. In Brazil, the LAMB strategy proved to be cost-effective for treating VL, considering a GDP per capita as the willingness-to-pay threshold, for all of the outcomes analysed in comparison to MA.

Abstract 27: Mining Big Data to Estimate the Frailty Index in Patients with Congestive Heart Failure: Clinical Expert vs Machine Learning

Introduction: Early recognition of frailty in older adults with Congestive Heart Failure (CHF) is needed to target interventions to slow functional decline and improve patient-centered outcomes. Previous studies have used laboratory values and vital signs to measure a frailty index (FI) to predict mortality; however, variable selection was based on expert opinion alone. Hypothesis: We hypothesize that a FI for CHF patients developed by mining laboratory values and vital signs with a machine learning algorithm will better predict mortality compared to a FI developed with expert opinion. Methods: This is a retrospective cohort study of patients with hospital admissions for CHF in the Veterans Health Administration from 2012 to 2014. Outpatient laboratory tests and vital signs where more than 50% of the cohort had a reported value were collected for the year prior to admission. Two physicians reviewed the laboratory tests and vital signs and used expert opinion to determine which variables may be associated with physical frailty. The laboratory tests and vital signs were also fed to a machine learning algorithm to select variables. We used the accumulation of deficits method to calculate the FI. Cox survival models were developed with the machine variables, expert opinion variables, and a combination (machine and expert). The outcome of interest was mortality. The performance of the models was compared by time dependent area under the curve (AUC) with 10-fold cross validation. Results: The cohort consisted of 24,457 patients (age 72±11 years, male 98%) with 70% mortality rate in six years. Out of 53 variables (49 laboratory tests and 4 vital signs), the physicians selected 29 variables, the machine selected 23, and the physicians and machine agreed on 14. The average AUC (95%CI) was 0.561 (0.561,0.562) for the expert opinion FI, 0.605 (0.604,0.606) for machine FI, and 0.607 (0.606,0.608) for combination FI. Conclusions: The FI developed using machine learning was a better predictor of mortality than a FI developed with expert opinion and used fewer variables. This study shows the potential for operationalizing a FI using laboratory values and vital signs from Electronic Health Records. In future studies, we plan to feed additional clinical variables to the machine learning algorithm to improve the accuracy of the FI model.

Impact of diagnosing and treating obstructive sleep apnea on healthcare utilization

PurposeObstructive sleep apnea (OSA) contributes to an increased risk for multiple co-morbidities and decreased quality of life. As a result, OSA patients may have higher usage of healthcare resources which can be mitigated with effective treatment. This study evaluates changes in healthcare utilization (HCU) following the initiation of therapy for OSA. MethodsWe conducted a retrospective study of newly diagnosed OSA patients. To assess total HCU, we incorporated the sum total of outpatient clinic encounters, laboratory tests, and medication prescriptions into a composite HCU score. Healthcare utilization for twelve months prior to positive airway pressure (PAP) was compared with twelve months after initiation of therapy. Reductions in HCU were correlated with PAP adherence. Results650 consecutive patients were included. Mean age, gender, BMI, AHI, and ESS were 47.2 ± 8.8 years, 77.2% (men), 30.7 ± 4.9 kg/m2, 37.1 ± 30.3, and 13.1 ± 5.1, respectively. Prior to PAP, mean outpatient visits, laboratory studies, medication prescriptions, and HCU composite score were 11.6 ± 10.4, 13.7 ± 11.0, 4.7 ± 3.2, and 29.7 ± 18.6, respectively. Following initiation of treatment, a 32.8% reduction in non-sleep outpatient visits was identified (p = 0.01) and a 16.4% decrease in laboratory studies (p = 0.02) was observed. There was a 19.9% reduction (p = 0.002) in HCU composite score. Those who were adherent with PAP had a 25.7% reduction in HCU composite score versus a 4.9% increase in those who discontinued PAP therapy (p < 0.001). ConclusionsDiagnosing OSA and initiating PAP therapy resulted in a significant decrease in healthcare resource utilization. This reduction was greatest among those with higher baseline healthcare usage and those most adherent with therapy.

Association of the frequency of pre-end-stage renal disease medical care with post-end-stage renal disease mortality and hospitalization.

Previous studies have demonstrated that early pre-end-stage renal disease (ESRD) nephrology care could improve postdialysis prognosis. However, less is known about the specific types of interventions responsible for the improved outcomes. We hypothesized that more frequent predialysis laboratory testing is associated with better postdialysis outcomes in incident ESRD patients. In all, 23 089 patients with available outpatient laboratory tests performed during the 2-year predialysis (i.e. prelude) period were identified from a total of 52 172 American veterans with chronic kidney disease (CKD) transitioning to dialysis between October 2007 and September 2011. The associations between the frequency of combined laboratory tests, including serum creatinine, serum potassium and hemoglobin (test trio), with postdialysis mortality and hospitalization were examined in multivariable adjusted Cox and logistic regression models. When entering the 2-year prelude period, the mean age (Standard Deviation) of the patients was 66.2 (SD 11.3) years and the mean estimated glomerular filtration rate was 46.8 (SD 23.9) mL/min/1.73 m2. In all, 14% of patients had the test trio performed less than twice in 24 months and 8.9% had the trio measured more often than every other month. Over a 2.5-year median postdialysis follow-up period, 15 303 (66.3%) patients died (mortality rate 260/1000 patient-years). The adjusted hazard ratio of all-cause mortality and adjusted odds ratio of the composite of hospitalization or death associated with lab testing done >12/24 months compared with 2-≤4/24 months were 0.68 [95% confidence interval (CI) 0.65-0.73] and 0.70 (95% CI 0.62-0.79), respectively. More frequent laboratory testing in patients with advanced CKD is associated with better clinical outcomes after dialysis. Further examination in clinical trials is needed before the implementation of more frequent laboratory testing in clinical practice.

Cost of Osteoporotic Fractures in Singapore

ObjectivesTo estimate the 3-month direct and indirect costs associated with osteoporotic fractures from both the hospital’s and patient’s perspectives in Singapore and to compare the cost between acute and prevalent osteoporotic fractures. MethodsResource use and expenditure data were collected using interviewer-administered questionnaires at baseline and at a 3-month follow-up between July 2013 and January 2014. Estimated osteoporotic fracture–related costs included hospitalizations, accident and emergency room visits, outpatient physician visits, laboratory tests, medications, transportation, health care and community services, special equipment and home/car modifications, and productivity loss. ResultsA total of 67 patients agreed to participate, giving a response rate of 64.4%. The mean (median) 3-month direct medical cost from the hospital’s perspective was found to be SGD 3,886.90 (SGD 413.10), of which 74.2% was accounted for by inpatient services, 25.2% by outpatient services, and 0.6% by accident and emergency services. Moreover, considerable variation (SD = SGD 2,615.40) was observed in the costs of outpatient rehabilitation services. Findings were similar when the patient’s perspective was taken. The total costs, with both direct and indirect costs included, were SGD 11,438.70 (acute) and SGD 1,015.40 (prevalent), of which 34.7% and 8.0%, respectively, were accounted for by inpatient services. ConclusionsHospitalization was associated with the highest cost borne by both the hospital and the patient, and informal care dominated indirect costs. Better knowledge of the financial consequences of fragility fractures could enable proactive and preventive measures to be undertaken, especially at sites of care with high cost drivers.

Risk factors for hospitalization of children with congenital adrenal hyperplasia.

Patients with congenital adrenal hyperplasia (CAH) owing to 21-hydroxylase deficiency are prone to potentially life-threatening adrenal crises. We tried to identify risk factors for postdiagnosis hospitalization for children with the salt-wasting form of CAH. We reviewed medical records of all children who presented to Children's Medical Center, Dallas, from 1999 to 2013 with CAH (ICD-9 code 255·2). Five hundred and twenty-two unique patients were coded for ICD-9 code of 255·2 (CAH) from 1999 to 2013; 155 patients had salt-wasting disease. Fifty-five patients were hospitalized a total of 105 times. Patients who were hospitalized were more likely to have noncommercial insurance (RR = 1·8; 95% CI [1·1-2·8]; P = 0·02); this included five patients hospitalized a total of 37 times. Children younger than 2 years (RR = 3·3 [2·2-4·8]; P < 0·0001) were more likely to be hospitalized. In a nested case-control analysis, the risk of hospitalization was correlated with daily fludrocortisone dose (P ≤ 0·0001) but not hydrocortisone dose; no outpatient laboratory test predicted hospitalization. Gastroenteritis was the most frequent admitting diagnosis. Younger children may be at greater risk of hospitalization owing to increased susceptibility to viral infections and decreased ability to withstand stress and dehydration. A minority of patients with noncommercial insurance may have higher risk owing to social barriers that interfere with treatment compliance. Those requiring higher daily fludrocortisone dosages likely have inherently more severe disease leading to higher rates of hospitalization.