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Yang J, Andersen KM, Rai KK, Tritton T, Mugwagwa T, Tsang C, Reimbaeva M, McGrath LJ, Payne P, Backhouse B, Mendes D, Butfield R, Wood R, Nguyen JL. Health Care Resource Utilization and Costs Associated With COVID-19 Among Pediatrics Managed in the Community or Hospital Setting in England: A Population-based Cohort Study. Pediatr Infect Dis J 2024; 43:209-216. [PMID: 38113517 DOI: 10.1097/inf.0000000000004213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
BACKGROUND Although COVID-19 morbidity is significantly lower in pediatrics than in adults, the risk of severe COVID-19 may still pose substantial health care resource burden. This study aimed to describe health care resource utilization (HCRU) and costs associated with COVID-19 in pediatrics 1-17 years old in England. METHODS A population-based retrospective cohort study of pediatrics with COVID-19 using Clinical Practice Research Datalink (CPRD Aurum) primary care data and, where available, linked Hospital Episode Statistics Admitted Patient Care secondary care data. HCRU and associated costs to the National Health Service were stratified by age, risk of severe COVID-19 and immunocompromised status, separately for those with and without hospitalization records (hospitalized cohort: COVID-19 diagnosis August 2020-March 2021; primary care cohort: COVID-19 diagnosis August 2020-January 2022). RESULTS This study included 564,644 patients in the primary care cohort and 60 in the hospitalized cohort. Primary care consultations were more common in those 1-4 years of age (face-to-face: 4.3%; telephone: 6.0%) compared with those 5-11 (2.0%; 2.1%) and 12-17 years of age (2.2%; 2.5%). In the hospitalized cohort, mean (SD) length of stay was longer [5.0 (5.8) days] among those 12-17 years old (n = 24) than those 1-4 [n = 15; 1.8 (0.9) days] and 5-11 years old [n = 21; 2.8 (2.1) days]. CONCLUSIONS Most pediatrics diagnosed with COVID-19 were managed in the community. However, hospitalizations were an important driver of HCRU and costs, particularly for those 12-17 years old. Our results may help optimize the management and resource allocation of COVID-19 in this population.
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Affiliation(s)
- Jingyan Yang
- From the Pfizer Inc, New York City, New York
- Institute for Social and Economic Research and Policy, Columbia University, New York City, New York
| | | | - Kiran K Rai
- Adelphi Real World, Bollington, United Kingdom
| | | | | | | | | | | | - Poppy Payne
- Adelphi Real World, Bollington, United Kingdom
| | | | | | | | - Robert Wood
- Adelphi Real World, Bollington, United Kingdom
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Carlson J, Foos V, Kasle A, Mugwagwa T, Draica F, Lee Wiemken T, Nguyen JL, Cha-Silva A, Migliaccio-Walle K, Dzingina M. Cost-Effectiveness of Oral Nirmatrelvir/Ritonavir in Patients at High Risk for Progression to Severe COVID-19 in the United States. Value Health 2024; 27:164-172. [PMID: 38043712 DOI: 10.1016/j.jval.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/27/2023] [Accepted: 11/22/2023] [Indexed: 12/05/2023]
Abstract
OBJECTIVES Nirmatrelvir/ritonavir (NMV/r) is an orally administered antiviral indicated for the outpatient treatment of patients with mild-to-moderate COVID-19 at high risk for disease progression to severe illness. We estimated the cost-effectiveness of NMV/r versus best supportive care for patients with mild-to-moderate COVID-19 at high risk for progression to severe illness from a US health sector perspective. METHODS A cost-effectiveness model was developed using a short-term decision-tree (1 year) followed by a lifetime 2-state Markov model (alive and dead). The short-term decision-tree captured costs and outcomes associated with the primary infection and healthcare utilization; survivors of the short-term decision-tree were followed until death assuming US quality-adjusted life years (QALYs), adjusted in the short-term for survivors of mechanical ventilation. Baseline rate of hospitalization and NMV/r effectiveness were taken from an Omicron-era US real-world study. Remaining inputs were informed by previous COVID-19 studies and publicly available US sources. Sensitivity analyses were conducted for all model inputs to test the robustness of model results. RESULTS NMV/r was found to decrease COVID-19 related hospitalizations (-0.027 per infected case) increase QALYs (+0.030), decrease hospitalization costs (-$1110), and increase total treatment cost (+$271), resulting in an incremental cost-effectiveness ratio of $8931/QALY. Results were most sensitive to baseline risk of hospitalization and NMV/r treatment effectiveness parameters. The probabilistic analysis indicated that NMV/r has a >99% probability of being cost-effective at a $100 000 willingness-to-pay threshold. CONCLUSIONS NMV/r is cost-effective vs best supportive care for patients at high risk for severe COVID-19 from a US health sector perspective.
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Affiliation(s)
- Josh Carlson
- Curta, Inc, Seattle, Washington, USA; The Comparative Health Outcomes, Policy, and Economics (CHOICE) Institute, University of Washington, Seattle, Washington, USA
| | - Volker Foos
- Health Economics and Outcomes Research, Ltd, Cardiff, Wales, UK
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Yang J, Andersen KM, Rai KK, Tritton T, Mugwagwa T, Reimbaeva M, Tsang C, McGrath LJ, Payne P, Backhouse BE, Mendes D, Butfield R, Naicker K, Araghi M, Wood R, Nguyen JL. Healthcare resource utilisation and costs of hospitalisation and primary care among adults with COVID-19 in England: a population-based cohort study. BMJ Open 2023; 13:e075495. [PMID: 38154885 PMCID: PMC10759085 DOI: 10.1136/bmjopen-2023-075495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 12/11/2023] [Indexed: 12/30/2023] Open
Abstract
OBJECTIVES To quantify direct costs and healthcare resource utilisation (HCRU) associated with acute COVID-19 in adults in England. DESIGN Population-based retrospective cohort study using Clinical Practice Research Datalink Aurum primary care electronic medical records linked to Hospital Episode Statistics secondary care administrative data. SETTING Patients registered to primary care practices in England. POPULATION 1 706 368 adults with a positive SARS-CoV-2 PCR or antigen test from August 2020 to January 2022 were included; 13 105 within the hospitalised cohort indexed between August 2020 and March 2021, and 1 693 263 within the primary care cohort indexed between August 2020 and January 2022. Patients with a COVID-19-related hospitalisation within 84 days of a positive test were included in the hospitalised cohort. MAIN OUTCOME MEASURES Primary and secondary care HCRU and associated costs ≤4 weeks following positive COVID-19 test, stratified by age group, risk of severe COVID-19 and immunocompromised status. RESULTS Among the hospitalised cohort, average length of stay, including critical care stays, was longer in older adults. Median healthcare cost per hospitalisation was higher in those aged 75-84 (£8942) and ≥85 years (£8835) than in those aged <50 years (£7703). While few (6.0%) patients in critical care required mechanical ventilation, its use was higher in older adults (50-74 years: 8.3%; <50 years: 4.3%). HCRU and associated costs were often greater in those at higher risk of severe COVID-19 than in the overall cohort, although minimal differences in HCRU were found across the three different high-risk definitions. Among the primary care cohort, general practitioner or nurse consultations were more frequent among older adults and the immunocompromised. CONCLUSIONS COVID-19-related hospitalisations in older adults, particularly critical care stays, were the primary drivers of high COVID-19 resource use in England. These findings may inform health policy decisions and resource allocation in the prevention and management of COVID-19.
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Affiliation(s)
- Jingyan Yang
- Pfizer Inc, New York, New York, USA
- The Institute for Social and Economic Research and Policy, Columbia University, New York, New York, USA
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Sandin R, Veenstra DL, Vankelegom M, Dzingina M, Sullivan SD, Campbell D, Ma C, Harrison C, Draica F, Wiemken TL, Mugwagwa T. Budget impact of oral nirmatrelvir/ritonavir in adults at high risk for progression to severe COVID-19 in the United States. J Manag Care Spec Pharm 2023; 29:1290-1302. [PMID: 38058141 PMCID: PMC10776264 DOI: 10.18553/jmcp.2023.29.12.1290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
BACKGROUND Nirmatrelvir/ritonavir (NMV/r) is indicated for the treatment of mild-to-moderate COVID-19 in adults who are at high risk for progression to severe COVID-19. NMV/r has also been authorized for emergency use by the US Food and Drug Administration for the treatment of mild-to-moderate COVID-19 in pediatric patients (aged 226512 years and weighing at least 40 kg) who are at high risk for progression to severe COVID-19. Understanding the budget impact of introducing NMV/r for the treatment of adults with COVID-19 is of key interest to US payers. OBJECTIVE To estimate the annual budget impact of introducing NMV/r in a US commercial health plan setting in the current Omicron COVID-19 era. METHODS A budget impact model was developed to assess the impact of NMV/r on health care costs in a hypothetical 1-million-member commercial health insurance plan over a 1-year period in the US population; clinical and cost inputs were derived from published literature with a focus on studies in the recent COVID-19 era that included vaccinated population and predominance of the Omicron variant. In the base-case analysis, it was assumed the only effect of NMV/r was a reduction in incidence (not severity) of hospitalization or death; its potential effect on post-COVID conditions was assessed in a scenario analysis. Outcomes included the number of hospitalizations, total cost, per patient per year (PPPY) costs, and per member per month (PMPM) costs. Sensitivity and scenario analyses were conducted to assess uncertainty around key model inputs. RESULTS An estimated 29,999 adults were eligible and sought treatment with oral antiviral for COVID-19 over 1 year. The availability of NMV/r was estimated to reduce the number of hospitalizations by 647 with a total budget impact of $2,733,745, $91 PPPY, and $0.23 PMPM. NMV/r was cost saving when including post-COVID conditions with a -$1,510,780 total budget impact, a PPPY cost of -$50, and a PMPM cost of -$0.13. Sensitivity analyses indicated results were most sensitive to the risk of hospitalization under supportive care, risk of hospitalization with NMV/r treatment and cost of NMV/r. CONCLUSIONS Treatment with NMV/r in the current COVID-19 era is estimated to result in substantial cost offsets because of reductions in hospitalization and modest budget impact to potential overall cost savings.
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Affiliation(s)
| | | | | | | | | | | | - Cuiying Ma
- Health Economics & Outcomes Research Ltd, Cardiff, Wales, UK
| | - Cale Harrison
- Health Economics & Outcomes Research Ltd, Cardiff, Wales, UK
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Hamson E, Forbes C, Wittkopf P, Pandey A, Mendes D, Kowalik J, Czudek C, Mugwagwa T. Impact of pandemics and disruptions to vaccination on infectious diseases epidemiology past and present. Hum Vaccin Immunother 2023:2219577. [PMID: 37291691 DOI: 10.1080/21645515.2023.2219577] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023] Open
Abstract
Infectious diseases are a leading cause of morbidity and mortality worldwide with vaccines playing a critical role in preventing deaths. To better understand the impact of low vaccination rates and previous epidemics on infectious disease rates, and how these may help to understand the potential impacts of the current coronavirus disease 2019 (COVID-19) pandemic, a targeted literature review was conducted. Globally, studies suggest past suboptimal vaccine coverage has contributed to infectious disease outbreaks in vulnerable populations. Disruptions caused by the COVID-19 pandemic have contributed to a decline in vaccination uptake and a reduced incidence in several infectious diseases; however, these rates have increased following the lifting of COVID-19 restrictions with modeling studies suggesting a risk of increased morbidity and mortality from several vaccine-preventable diseases. This suggests a window of opportunity to review vaccination and infectious disease control measures before we see further disease resurgence in populations and age-groups currently unaffected.
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Mendes D, Averin A, Atwood M, Sato R, Vyse A, Campling J, Weycker D, Slack M, Ellsbury G, Mugwagwa T. Cost-effectiveness of using a 20-valent pneumococcal conjugate vaccine to directly protect adults in England at elevated risk of pneumococcal disease. Expert Rev Pharmacoecon Outcomes Res 2022; 22:1285-1295. [PMID: 36225103 DOI: 10.1080/14737167.2022.2134120] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES Despite the current pneumococcal vaccination program in England for older adults and adults with underlying conditions, disease burden remains high. We evaluated cost-effectiveness of 20-valent pneumococcal conjugate vaccine (PCV20) compared to current pneumococcal recommendations for adults in England. METHODS Lifetime outcomes/costs of invasive pneumococcal disease (IPD) and community-acquired pneumonia (CAP) among adults aged 65-99 years and adults aged 18-64 years with underlying conditions in England were projected using a probabilistic cohort model. Vaccination with PCV20 was compared with 23-valent pneumococcal polysaccharide vaccine (PPV23) from the National Health Service perspective. RESULTS PCV20 was cost saving compared with PPV23 in base case and most sensitivity analyses. In the base case, replacing PPV23 with PCV20 prevented 7,789 and 140,046 cases of IPD and hospitalized CAP, respectively, and 22,199 associated deaths, resulting in incremental gain of 91,375 quality-adjusted life-years (QALYs) and incremental savings of £160M. In probabilistic sensitivity analyses, PCV20 (vs. PPV23) was cost saving in 85% of simulations; incremental cost per QALY was below £30,000 in 99% of simulations. CONCLUSIONS PCV20 vaccination in adults aged 65-99 years and those aged 18-64 years with underlying comorbidities in England is expected to prevent more hospitalizations, save more lives, and yield lower overall costs than current recommendations for PPV23.
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Affiliation(s)
| | | | - Mark Atwood
- Policy Analysis Inc. (PAI), Chestnut Hill, MA
| | | | | | | | | | - Mary Slack
- School of Medicine & Dentistry, Griffith University, Gold Coast Campus, Queensland 4222, Australia
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Mugwagwa T, Averin A, Atwood M, Sato R, Vyse A, Campling J, Weycker D, Slack M, Ellsbury G, Mendes D. Public health and budgetary impact of 20-valent pneumococcal conjugate vaccine for adults in England. Expert Rev Vaccines 2022; 21:1331-1341. [PMID: 35929956 DOI: 10.1080/14760584.2022.2104250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND . Despite use of 23-valent pneumococcal polysaccharide vaccine (PPV23) in England, disease burden among at-risk adults remains high. We evaluated the public health and budgetary impact of 20-valent pneumococcal conjugate vaccine (PCV20) compared to the current adult pneumococcal vaccination program. METHODS Five-year outcomes and costs of invasive pneumococcal disease (IPD) and community-acquired pneumonia (CAP) among adults aged 65-99 years and adults aged 18-64 years with underlying conditions in England were projected using a deterministic cohort model. Hypothetical vaccination with PCV20 versus PPV23 was compared from National Health Service (NHS) perspective. RESULTS Replacing PPV23 with PCV20 would prevent 785 IPD hospitalizations, 11,751 CAP hospitalizations, and 1,414 deaths over five years, and would reduce medical care costs by £48.5M. With vaccination costs higher by £107.2M, projected net budgetary impact is £58.7M. The budgetary impact would be greatest in year one (£26.3M), and would decrease over time (to £1.6M by year five). The average budget increase (£11.7M/year) represents <0.01% of the Department of Health and Social Care budget and <3% of the vaccines budget. CONCLUSIONS Use of PCV20 among adults currently eligible for PPV23 in England would substantially reduce the burden of pneumococcal disease, with modest budgetary impact.
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Affiliation(s)
| | | | - Mark Atwood
- Policy Analysis Inc. (PAI), Chestnut Hill, MA
| | | | | | | | | | - Mary Slack
- School of Medicine & Dentistry, Griffith University, Gold Coast Campus, Queensland 4222, Australia
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Abstract
OBJECTIVE Accurate and up-to-date figures of the cost of community-acquired pneumonia (CAP) hospitalization are needed to understand the associated economic burden for public health decision-makers. Recent estimates are lacking, and previously published estimates differ markedly. Our objective was to estimate the current mean cost to the UK National Health Service (NHS) for adult hospitalized CAP. METHODS All CAP hospitalizations in 2019 for those aged ≥18 years were identified from English Hospital Episode Statistics (HES). Each hospitalization was mapped to the tariff cost paid to the care provider within the NHS, including critical care costs and accounting for length of stay and complexity of the case. Mean hospitalization costs were estimated in total and in individuals with defined underlying comorbidities. RESULTS A mean cost of £3,904 was estimated for 187,251 CAP admissions providing a total cost of approximately £731 million per annum. The mean cost was £3,402, excluding critical care costs, and £11,654 for critical care episodes in the 4.4% of admissions receiving this care. Groups at high risk of CAP had higher mean costs, ranging from £4,458 for people with diabetes to £5,215 for those with heart disease aged <65 years and £4,356 for those with heart disease to £4,751 for those with liver disease aged >65 years who comprised 74.3% of admissions overall. CONCLUSION This estimate of the cost of hospitalization for CAP from the total population and in those with certain underlying comorbidities will allow a valid understanding of the cost-benefit of vaccination and evidence-based prioritization of pneumococcal vaccination to those at highest risk.
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Affiliation(s)
- James Campling
- Vaccines Medical Affairs, Pfizer Ltd. UK, Tadworth, Surrey, UK
| | - Hannah F Wright
- Vaccines Medical Affairs, Pfizer Ltd. UK, Tadworth, Surrey, UK
| | | | | | - Andrew Vyse
- Vaccines Medical Affairs, Pfizer Ltd. UK, Tadworth, Surrey, UK
| | - Diana Mendes
- Health & Value, Pfizer Ltd. UK, Tadworth, Surrey, UK
| | - Mary P E Slack
- School of Medicine & Dentistry, Griffith University, Southport, Queensland, Australia
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9
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Mugwagwa T, Abubakar I, White PJ. Using molecular testing and whole-genome sequencing for tuberculosis diagnosis in a low-burden setting: a cost-effectiveness analysis using transmission-dynamic modelling. Thorax 2021; 76:281-291. [PMID: 33542086 DOI: 10.1136/thoraxjnl-2019-214004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/08/2020] [Accepted: 10/26/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND Despite progress in TB control in low-burden countries like England and Wales, there are still diagnostic delays. Molecular testing and/or whole-genome sequencing (WGS) provide more rapid diagnosis but their cost-effectiveness is relatively unexplored in low-burden settings. METHODS An integrated transmission-dynamic health economic model is used to assess the cost-effectiveness of using WGS to replace culture-based drug-sensitivity testing, versus using molecular testing versus combined use of WGS and molecular testing, for routine TB diagnosis. The model accounts for the effects of faster appropriate treatment in reducing transmission, benefiting health and reducing future treatment costs. Cost-effectiveness is assessed using incremental net benefit (INB) over a 10-year horizon with a quality-adjusted life-year valued at £20 000, and discounting at 3.5% per year. RESULTS WGS shortens the time to drug sensitivity testing and treatment modification where necessary, reducing treatment and hospitalisation costs, with an INB of £7.1 million. Molecular testing shortens the time to TB diagnosis and treatment. Initially, this causes an increase in annual costs of treatment, but averting transmissions and future active TB disease subsequently, resulting in cost savings and health benefits to achieve an INB of £8.6 million (GeneXpert MTB/RIF) or £11.1 million (Xpert-Ultra). Combined use of Xpert-Ultra and WGS is the optimal strategy we consider, with an INB of £16.5 million. CONCLUSION Routine use of WGS or molecular testing is cost-effective in a low-burden setting, and combined use is the most cost-effective option. Adoption of these technologies can help low-burden countries meet the WHO End TB Strategy milestones, particularly the UK, which still has relatively high TB rates.
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Affiliation(s)
- Tendai Mugwagwa
- Modelling and Economics Unit, National Infection Service, Public Health England, London, UK.,MRC Centre for Global Infectious Disease Analysis and NIHR Health Protection Research Unit in Modelling and Health Economics, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Ibrahim Abubakar
- Institute for Global Health, University College London, London, UK
| | - Peter J White
- Modelling and Economics Unit, National Infection Service, Public Health England, London, UK .,MRC Centre for Global Infectious Disease Analysis and NIHR Health Protection Research Unit in Modelling and Health Economics, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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10
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Mugwagwa T, Stagg HR, Abubakar I, White PJ. Comparing different technologies for active TB case-finding among the homeless: a transmission-dynamic modelling study. Sci Rep 2018; 8:1433. [PMID: 29362378 PMCID: PMC5780390 DOI: 10.1038/s41598-018-19757-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/13/2017] [Indexed: 01/06/2023] Open
Abstract
Homeless persons have elevated risk of tuberculosis (TB) and are under-served by conventional health services. Approaches to active case-finding (ACF) and treatment tailored to their needs are required. A transmission-dynamic model was developed to assess the effectiveness and efficiency of screening with mobile Chest X-ray, GeneXpert, or both. Effectiveness of ACF depends upon the prevalence of infection in the population (which determines screening 'yield'), patient willingness to wait for GeneXpert results, and treatment adherence. ACF is efficient when TB prevalence exceeds 78/100,000 and 46% of drug sensitive TB cases and 33% of multi-drug resistant TB cases complete treatment. This threshold increases to 92/100,000 if additional post-ACF enhanced case management (ECM) increases treatment completion to 85%. Generally, the most efficient option is one-step screening of all patients with GeneXpert, but if too many patients (>27% without ECM, >19% with ECM) are unwilling to wait the 90 minutes required then two-step screening using chest X-ray (which is rapid) followed by GeneXpert for confirmation of TB is the most efficient option. Targeted ACF and support services benefit health through early successful treatment and averting TB transmission and disease. The optimal strategy is setting-specific, requiring careful consideration of patients' needs regarding testing and treatment.
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Affiliation(s)
- Tendai Mugwagwa
- Modelling and Economics Unit, National Infection Service, Public Health England, London, UK.
- MRC Centre for Outbreak Analysis and Modelling, and NIHR Health Protection Research Unit in Modelling Methodology, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
| | - Helen R Stagg
- Institute for Global Health, Faculty of Population Health Sciences, University College London, London, UK
| | - Ibrahim Abubakar
- Institute for Global Health, Faculty of Population Health Sciences, University College London, London, UK
- Medical Directorate, Public Health England, London, UK
| | - Peter J White
- Modelling and Economics Unit, National Infection Service, Public Health England, London, UK
- MRC Centre for Outbreak Analysis and Modelling, and NIHR Health Protection Research Unit in Modelling Methodology, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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van Hoeven V, Drylewicz J, Westera L, den Braber I, Mugwagwa T, Tesselaar K, Borghans JAM, de Boer RJ. Dynamics of Recent Thymic Emigrants in Young Adult Mice. Front Immunol 2017; 8:933. [PMID: 28824653 PMCID: PMC5545745 DOI: 10.3389/fimmu.2017.00933] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 07/21/2017] [Indexed: 11/13/2022] Open
Abstract
The peripheral naive T-cell pool is generally thought to consist of a subpopulation of recent thymic emigrants (RTEs) and a subpopulation of mature naive (MN) T cells with different dynamics. Thymus transplantation and adoptive transfer studies in mice have provided contradicting results, with some studies suggesting that RTEs are relatively short-lived cells, while another study suggested that RTEs have a survival advantage. We here estimate the death rates of RTE and MN T cells by performing both thymus transplantations and deuterium labeling experiments in mice of at least 12 weeks old, an age at which the size of the T-cell pool has stabilized. For CD4+ T cells, we found the total loss rate from the RTE compartment (by death and maturation) to be fourfold faster than that of MN T cells. We estimate the death rate of CD4+ RTE to be 0.046 per day, which is threefold faster than the total loss rate from the MN T-cell compartment. For CD8+ T cells, we found no evidence for kinetic differences between RTE and MN T cells. Thus, our data support the notion that in young adult mice, CD4+ RTE are relatively short-lived cells within the naive CD4+ T-cell pool.
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Affiliation(s)
- Vera van Hoeven
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Julia Drylewicz
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands.,Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, Netherlands
| | - Liset Westera
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Ineke den Braber
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Tendai Mugwagwa
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, Netherlands
| | - Kiki Tesselaar
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - José A M Borghans
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Rob J de Boer
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, Netherlands
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12
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Drylewicz J, Vrisekoop N, Mugwagwa T, de Boer AB, Otto SA, Hazenberg MD, Tesselaar K, de Boer RJ, Borghans JAM. Reconciling Longitudinal Naive T-Cell and TREC Dynamics during HIV-1 Infection. PLoS One 2016; 11:e0152513. [PMID: 27010200 PMCID: PMC4806918 DOI: 10.1371/journal.pone.0152513] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/15/2016] [Indexed: 12/14/2022] Open
Abstract
Naive T cells in untreated HIV-1 infected individuals have a reduced T-cell receptor excision circle (TREC) content. Previous mathematical models have suggested that this is due to increased naive T-cell division. It remains unclear, however, how reduced naive TREC contents can be reconciled with a gradual loss of naive T cells in HIV-1 infection. We performed longitudinal analyses in humans before and after HIV-1 seroconversion, and used a mathematical model to investigate which processes could explain the observed changes in naive T-cell numbers and TRECs during untreated HIV-1 disease progression. Both CD4+ and CD8+ naive T-cell TREC contents declined biphasically, with a rapid loss during the first year and a much slower loss during the chronic phase of infection. While naive CD8+ T-cell numbers hardly changed during follow-up, naive CD4+ T-cell counts continually declined. We show that a fine balance between increased T-cell division and loss in the peripheral naive T-cell pool can explain the observed short- and long-term changes in TRECs and naive T-cell numbers, especially if T-cell turnover during the acute phase is more increased than during the chronic phase of infection. Loss of thymic output, on the other hand, does not help to explain the biphasic loss of TRECs in HIV infection. The observed longitudinal changes in TRECs and naive T-cell numbers in HIV-infected individuals are most likely explained by a tight balance between increased T-cell division and death, suggesting that these changes are intrinsically linked in HIV infection.
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Affiliation(s)
- Julia Drylewicz
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
- Theoretical Biology & Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Nienke Vrisekoop
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Tendai Mugwagwa
- Theoretical Biology & Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Anne Bregje de Boer
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Sigrid A. Otto
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mette D. Hazenberg
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kiki Tesselaar
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rob J. de Boer
- Theoretical Biology & Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - José A. M. Borghans
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
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Drobniewski F, Cooke M, Jordan J, Casali N, Mugwagwa T, Broda A, Townsend C, Sivaramakrishnan A, Green N, Jit M, Lipman M, Lord J, White PJ, Abubakar I. Systematic review, meta-analysis and economic modelling of molecular diagnostic tests for antibiotic resistance in tuberculosis. Health Technol Assess 2016; 19:1-188, vii-viii. [PMID: 25952553 DOI: 10.3310/hta19340] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Drug-resistant tuberculosis (TB), especially multidrug-resistant (MDR, resistance to rifampicin and isoniazid) disease, is associated with a worse patient outcome. Drug resistance diagnosed using microbiological culture takes days to weeks, as TB bacteria grow slowly. Rapid molecular tests for drug resistance detection (1 day) are commercially available and may promote faster initiation of appropriate treatment. OBJECTIVES To (1) conduct a systematic review of evidence regarding diagnostic accuracy of molecular genetic tests for drug resistance, (2) conduct a health-economic evaluation of screening and diagnostic strategies, including comparison of alternative models of service provision and assessment of the value of targeting rapid testing at high-risk subgroups, and (3) construct a transmission-dynamic mathematical model that translates the estimates of diagnostic accuracy into estimates of clinical impact. REVIEW METHODS AND DATA SOURCES A standardised search strategy identified relevant studies from EMBASE, PubMed, MEDLINE, Bioscience Information Service (BIOSIS), System for Information on Grey Literature in Europe Social Policy & Practice (SIGLE) and Web of Science, published between 1 January 2000 and 15 August 2013. Additional 'grey' sources were included. Quality was assessed using quality assessment of diagnostic accuracy studies version 2 (QUADAS-2). For each diagnostic strategy and population subgroup, a care pathway was constructed to specify which medical treatments and health services that individuals would receive from presentation to the point where they either did or did not complete TB treatment successfully. A total cost was estimated from a health service perspective for each care pathway, and the health impact was estimated in terms of the mean discounted quality-adjusted life-years (QALYs) lost as a result of disease and treatment. Costs and QALYs were both discounted at 3.5% per year. An integrated transmission-dynamic and economic model was used to evaluate the cost-effectiveness of introducing rapid molecular testing (in addition to culture and drug sensitivity testing). Probabilistic sensitivity analysis was performed to evaluate the impact on cost-effectiveness of diagnostic and treatment time delays, diagnosis and treatment costs, and associated QALYs. RESULTS A total of 8922 titles and abstracts were identified, with 557 papers being potentially eligible. Of these, 56 studies contained sufficient test information for analysis. All three commercial tests performed well when detecting drug resistance in clinical samples, although with evidence of heterogeneity between studies. Pooled sensitivity for GenoType® MTBDRplus (Hain Lifescience, Nehren, Germany) (isoniazid and rifampicin resistance), INNO-LiPA Rif.TB® (Fujirebio Europe, Ghent, Belgium) (rifampicin resistance) and Xpert® MTB/RIF (Cepheid Inc., Sunnyvale, CA, USA) (rifampicin resistance) was 83.4%, 94.6%, 95.4% and 96.8%, respectively; equivalent pooled specificity was 99.6%, 98.2%, 99.7% and 98.4%, respectively. Results of the transmission model suggest that all of the rapid assays considered here, if added to the current diagnostic pathway, would be cost-saving and achieve a reduction in expected QALY loss compared with current practice. GenoType MTBDRplus appeared to be the most cost-effective of the rapid tests in the South Asian population, although results were similar for GeneXpert. In all other scenarios GeneXpert appeared to be the most cost-effective strategy. CONCLUSIONS Rapid molecular tests for rifampicin and isoniazid resistance were sensitive and specific. They may also be cost-effective when added to culture drug susceptibility testing in the UK. There is global interest in point-of-care testing and further work is needed to review the performance of emerging tests and the wider health-economic impact of decentralised testing in clinics and primary care, as well as non-health-care settings, such as shelters and prisons. STUDY REGISTRATION This study is registered as PROSPERO CRD42011001537. FUNDING The National Institute for Health Research Health Technology Assessment programme.
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Affiliation(s)
- Francis Drobniewski
- Public Health England National Mycobacterium Reference Laboratory, London, UK
| | - Mary Cooke
- Centre for Infectious Disease Epidemiology, Research Department of Infection and Population Health, University College London, London, UK
| | - Jake Jordan
- Health Economics Research Group, Brunel University, Uxbridge, UK
| | - Nicola Casali
- Department of Infectious Diseases and Immunity, Imperial College London, London, UK
| | - Tendai Mugwagwa
- Modelling and Economics Unit, Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK
| | - Agnieszka Broda
- Department of Infectious Diseases and Immunity, Imperial College London, London, UK
| | | | | | - Nathan Green
- Modelling and Economics Unit, Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK
| | - Mark Jit
- Modelling and Economics Unit, Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK
| | - Marc Lipman
- Division of Medicine, University College London, London, UK
| | - Joanne Lord
- Health Economics Research Group, Brunel University, Uxbridge, UK
| | - Peter J White
- Modelling and Economics Unit, Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK
| | - Ibrahim Abubakar
- Centre for Infectious Disease Epidemiology, Research Department of Infection and Population Health, University College London, London, UK
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den Braber I, Mugwagwa T, Vrisekoop N, Westera L, Mögling R, Bregje de Boer A, Willems N, Schrijver E, Spierenburg G, Gaiser K, Mul E, Otto S, Ruiter A, Ackermans M, Miedema F, Borghans J, de Boer R, Tesselaar K. Maintenance of Peripheral Naive T Cells Is Sustained by Thymus Output in Mice but Not Humans. Immunity 2012; 36:288-97. [DOI: 10.1016/j.immuni.2012.02.006] [Citation(s) in RCA: 388] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 05/02/2011] [Accepted: 12/06/2011] [Indexed: 12/25/2022]
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Vrisekoop N, Den Braber I, Mugwagwa T, Westera L, Mogling R, De Boer AB, Willems N, Schrijver E, Spierenburg G, Gaiser K, Mul E, Otto S, Ruiter A, Ackermans M, Miedema F, Borghans J, De Boer R, Tesselaar K. Maintenance of peripheral naive T cells: a mouse-man divide (159.1). The Journal of Immunology 2011. [DOI: 10.4049/jimmunol.186.supp.159.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Insights from T-cell dynamic studies in mice are widely extrapolated to men and vice versa, while no formal proof exists that such extrapolations are justified. At the same time, there is a lot of controversy about the dynamic properties of T cells, including life span and the relative contributions of thymus output and peripheral proliferation to the maintenance of the naive T-cell pool during aging. We have investigated the hypothesis that part of this controversy is due to improper extrapolation of dynamic parameters of T cells from mice to men. By combining in vivo kinetic labeling using deuterated water, thymectomy experiments, analysis of TRECs, the expression of the thymic proximity marker CD31, and mathematical modeling, we have quantified the contributions of de novo T-cell production by the thymus and peripheral naive T-cell division to life-long maintenance of the naive T-cell pool in both mice and men under normal physiological conditions. Our results show that mice and men are incomparable with respect to naive T-cell maintenance. While in mice - throughout their life time - the naive T-cell pool is almost exclusively sustained by thymus output, the maintenance of the adult human naive T-cell pool occurs almost exclusively through peripheral T-cell division. These findings put serious constraints on the use of mouse experiments to understand immunological processes such as T-cell reconstitution in lymphopenic patients or the effects of aging in healthy humans.
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Affiliation(s)
| | | | | | - Liset Westera
- 1University Medical Center Utrecht, Utrecht, Netherlands
| | - Ramona Mogling
- 1University Medical Center Utrecht, Utrecht, Netherlands
| | | | | | | | | | - Koos Gaiser
- 1University Medical Center Utrecht, Utrecht, Netherlands
| | - Erik Mul
- 3Sanquin Research, Landsteiner Lab and Academic Medical Center, Amsterdam, Netherlands
| | - Sigrid Otto
- 1University Medical Center Utrecht, Utrecht, Netherlands
| | - An Ruiter
- 4Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Mariette Ackermans
- 4Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Frank Miedema
- 1University Medical Center Utrecht, Utrecht, Netherlands
| | - Jose Borghans
- 1University Medical Center Utrecht, Utrecht, Netherlands
| | | | - Kiki Tesselaar
- 1University Medical Center Utrecht, Utrecht, Netherlands
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Mugwagwa T, Witten G. Coreceptor switching in HIV-1 subtype B and subtype C. Bull Math Biol 2006; 69:55-75. [PMID: 17086370 DOI: 10.1007/s11538-006-9137-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Accepted: 09/26/2005] [Indexed: 10/24/2022]
Abstract
We use a mathematical model to determine the factors affecting the delayed or rare coreceptor switch in HIV-1 subtype C infected individuals. The model takes into account the two main target cells for the CXCR4-tropic and CCR5-tropic virus and includes the the lytic and non-lytic immune responses. Computer-based simulations and a sensitivity analysis of the model predict that a persistent immune response suppresses the CXCR4-tropic virus to low levels and hence preventing a phenotypic switch. However, not only should the immune response be persistent, but it should have an efficient lytic immune response rather that an efficient non-lytic response. In addition, we also find that the availability of macrophage cells and enhanced viral kinetics are also crucial for the dominance of the R5 strain. We suggest that an altered host environment probably as a result of immune activation may explain the difference in coreceptor switching kinetics between HIV-1 subtype B and subtype C individuals.
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Affiliation(s)
- T Mugwagwa
- Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town, South Africa
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