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3.
Mult Scler ; 29(1): 130-139, 2023 01.
Article in English | MEDLINE | ID: mdl-36177953

ABSTRACT

BACKGROUND: The current standard endpoint to assess disability accumulation in multiple sclerosis (MS) clinical trials is the time to the first confirmed disability progression, which excludes subsequent progression events. Including recurrent progression events may permit a more comprehensive assessment of treatment effects on disability progression. OBJECTIVE: To propose a definition of recurrent disability progression events and to compare time-to-first and recurrent event analysis. METHODS: Recurrent disability progression events were defined by expanding the recommended first event definition. Marginal recurrent event methods (negative binomial model, Lin-Wei-Yang-Ying model) were compared with Cox regression in data from three randomized controlled trials in relapsing multiple sclerosis (RMS) and primary progressive multiple sclerosis (PPMS), and in simulated randomized controlled trial data. RESULTS: The recurrent event analyses included a substantially larger number of progression events compared with the time-to-first-event analyses (+7.5% and +9.9% in the RMS trials and +22.7% in the PPMS trial). The increase in the number of events resulted in more precise treatment effect estimates and a corresponding gain in statistical power. CONCLUSION: Our results support the use of recurrent event data analysis, especially in progressive MS trials, to improve estimates of treatment effects, increase statistical power, and better capture the clinically meaningful long-term disability progression experience.


Subject(s)
Multiple Sclerosis, Chronic Progressive , Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , Humans , Multiple Sclerosis/drug therapy , Multiple Sclerosis, Chronic Progressive/drug therapy , Models, Statistical , Recurrence , Disease Progression , Multiple Sclerosis, Relapsing-Remitting/drug therapy
4.
Pharm Stat ; 21(6): 1246-1257, 2022 11.
Article in English | MEDLINE | ID: mdl-35587109

ABSTRACT

Clinical trials with longitudinal outcomes typically include missing data due to missed assessments or structural missingness of outcomes after intercurrent events handled with a hypothetical strategy. Approaches based on Bayesian random multiple imputation and Rubin's rules for pooling results across multiple imputed data sets are increasingly used in order to align the analysis of these trials with the targeted estimand. We propose and justify deterministic conditional mean imputation combined with the jackknife for inference as an alternative approach. The method is applicable to imputations under a missing-at-random assumption as well as for reference-based imputation approaches. In an application and a simulation study, we demonstrate that it provides consistent treatment effect estimates with the Bayesian approach and reliable frequentist inference with accurate standard error estimation and type I error control. A further advantage of the method is that it does not rely on random sampling and is therefore replicable and unaffected by Monte Carlo error.


Subject(s)
Research Design , Humans , Data Interpretation, Statistical , Bayes Theorem , Computer Simulation , Monte Carlo Method
5.
Pharm Stat ; 20(4): 737-751, 2021 07.
Article in English | MEDLINE | ID: mdl-33624407

ABSTRACT

A randomized trial allows estimation of the causal effect of an intervention compared to a control in the overall population and in subpopulations defined by baseline characteristics. Often, however, clinical questions also arise regarding the treatment effect in subpopulations of patients, which would experience clinical or disease related events post-randomization. Events that occur after treatment initiation and potentially affect the interpretation or the existence of the measurements are called intercurrent events in the ICH E9(R1) guideline. If the intercurrent event is a consequence of treatment, randomization alone is no longer sufficient to meaningfully estimate the treatment effect. Analyses comparing the subgroups of patients without the intercurrent events for intervention and control will not estimate a causal effect. This is well known, but post-hoc analyses of this kind are commonly performed in drug development. An alternative approach is the principal stratum strategy, which classifies subjects according to their potential occurrence of an intercurrent event on both study arms. We illustrate with examples that questions formulated through principal strata occur naturally in drug development and argue that approaching these questions with the ICH E9(R1) estimand framework has the potential to lead to more transparent assumptions as well as more adequate analyses and conclusions. In addition, we provide an overview of assumptions required for estimation of effects in principal strata. Most of these assumptions are unverifiable and should hence be based on solid scientific understanding. Sensitivity analyses are needed to assess robustness of conclusions.


Subject(s)
Drug Development , Research Design , Causality , Data Interpretation, Statistical , Humans
6.
Wellcome Open Res ; 6: 207, 2021.
Article in English | MEDLINE | ID: mdl-35097222

ABSTRACT

Background: Typhoid and paratyphoid fever (enteric fever) is a common cause of non-specific febrile infection in adults and children presenting to health care facilities in low resource settings such as the South Asia.  A 7-day course of a single oral antimicrobial such as ciprofloxacin, cefixime or azithromycin is commonly used for its treatment. Increasing antimicrobial resistance threatens the effectiveness of these treatment choices. We hypothesize that combined treatment with azithromycin (active mainly intracellularly) and cefixime (active mainly extracellularly) will be a better option for the treatment of typhoid fever in South Asia. Methods: This is a phase IV, international multi-centre, multi-country, comparative participant-and observer-blind, 1:1 randomised clinical trial. Patients with suspected uncomplicated typhoid fever will be randomised to one of the two interventions: Arm A: azithromycin 20mg/kg/day oral dose once daily (maximum 1gm/day) and cefixime 20mg/kg/day oral dose in two divided doses (maximum 400mg bd) for 7 days, Arm B: azithromycin 20mg/kg/day oral dose once daily (max 1gm/day) for 7 days AND cefixime-matched placebo for 7 days. We will recruit 1500 patients across sites in Bangladesh, India, Nepal and Pakistan. We will assess whether treatment outcomes are better with the combination after one week of treatment and at one- and three-months follow-up. Discussion: Combined treatment may limit the emergence of resistance if one of the components is active against resistant sub-populations not covered by the other antimicrobial's activity. If the combined treatment is better than the single antimicrobial treatment, this will be an important result for patients across South Asia and other typhoid endemic areas. Clinicaltrials.gov registration: NCT04349826 (16/04/2020).

7.
Clin Infect Dis ; 73(7): e2338-e2341, 2021 10 05.
Article in English | MEDLINE | ID: mdl-33051650

ABSTRACT

We investigated the value of susceptibility testing in predicting response in AIDS-associated cryptococcal meningitis using clinical isolates from a randomized controlled trial of antifungal treatment (amphotericin monotherapy, amphotericin with flucytosine, or amphotericin with fluconazole). We found no correlation between antifungal susceptibility and either early or late survival, or fungal clearance.


Subject(s)
Acquired Immunodeficiency Syndrome , Meningitis, Cryptococcal , Acquired Immunodeficiency Syndrome/complications , Acquired Immunodeficiency Syndrome/drug therapy , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Fluconazole/pharmacology , Fluconazole/therapeutic use , Flucytosine/therapeutic use , Humans , Meningitis, Cryptococcal/drug therapy
8.
Pharm Stat ; 20(2): 202-211, 2021 03.
Article in English | MEDLINE | ID: mdl-32869509

ABSTRACT

One of the challenges in the design of confirmatory trials is to deal with uncertainties regarding the optimal target population for a novel drug. Adaptive enrichment designs (AED) which allow for a data-driven selection of one or more prespecified biomarker subpopulations at an interim analysis have been proposed in this setting but practical case studies of AEDs are still relatively rare. We present the design of an AED with a binary endpoint in the highly dynamic setting of cancer immunotherapy. The trial was initiated as a conventional trial in early triple-negative breast cancer but amended to an AED based on emerging data external to the trial suggesting that PD-L1 status could be a predictive biomarker. Operating characteristics are discussed including the concept of a minimal detectable difference, that is, the smallest observed treatment effect that would lead to a statistically significant result in at least one of the target populations at the interim or the final analysis, respectively, in the setting of AED.


Subject(s)
Neoplasms , Research Design , Adaptive Clinical Trials as Topic , Biomarkers , Humans , Immunotherapy , Neoplasms/therapy , Pragmatic Clinical Trials as Topic
9.
Stat Biopharm Res ; 12(4): 399-411, 2020 Jul 06.
Article in English | MEDLINE | ID: mdl-34191971

ABSTRACT

Abstract-The COVID-19 pandemic has had and continues to have major impacts on planned and ongoing clinical trials. Its effects on trial data create multiple potential statistical issues. The scale of impact is unprecedented, but when viewed individually, many of the issues are well defined and feasible to address. A number of strategies and recommendations are put forward to assess and address issues related to estimands, missing data, validity and modifications of statistical analysis methods, need for additional analyses, ability to meet objectives and overall trial interpretability.

10.
Clin Infect Dis ; 70(5): 827-834, 2020 02 14.
Article in English | MEDLINE | ID: mdl-30944929

ABSTRACT

BACKGROUND: Pretreatment predictors of death from tuberculous meningitis (TBM) are well established, but whether outcome can be predicted more accurately after the start of treatment by updated clinical variables is unknown. Hence, we developed and validated models that dynamically predict mortality using time-updated Glasgow Coma Scale (GCS) and plasma sodium measurements, together with patient baseline characteristics. METHODS: We included 1048 adults from 4 TBM studies conducted in southern Vietnam from 2004 to 2016. We used a landmarking approach to predict death within 120 days after treatment initiation using time-updated data during the first 30 days of treatment. Separate models were built for patients with and without human immunodeficiency virus (HIV) infection. We used the area under the receiver operating characteristic curve (AUC) to evaluate performance of the models at days 10, 20, and 30 of treatment to predict mortality by 60, 90, and 120 days. Our internal validation was corrected for overoptimism using bootstrap. We provide a web-based application that computes mortality risk within 120 days. RESULTS: Higher GCS indicated better prognosis in all patients. In HIV-infected patients, higher plasma sodium was uniformly associated with good prognosis, whereas in HIV-uninfected patients the association was heterogeneous over time. The bias-corrected AUC of the models ranged from 0.82 to 0.92 and 0.81 to 0.85 in HIV-uninfected and HIV-infected individuals, respectively. The models outperformed the previously published baseline models. CONCLUSIONS: Time-updated GCS and plasma sodium measurements improved predictions based solely on information obtained at diagnosis. Our models may be used in practice to define those with poor prognosis during treatment.


Subject(s)
Tuberculosis, Meningeal , Adult , Glasgow Coma Scale , Humans , Plasma , Prognosis , Sodium , Tuberculosis, Meningeal/diagnosis , Vietnam
11.
J Infect ; 78(6): 454-460, 2019 06.
Article in English | MEDLINE | ID: mdl-30914268

ABSTRACT

OBJECTIVES: We assessed the impact of MALDITOF-MS on the timeliness of optimal antimicrobial therapy through a parallel-arm randomised controlled trial in two hospitals in Vietnam. METHODS: We recruited patients with a pathogen (bacterial or fungal) cultured from a normally sterile sample. Samples were randomly assigned (1:1) to identification by MALDITOF-MS or conventional diagnostics. The primary outcome was the proportion on optimal antimicrobial therapy within 24 h of positive culture, determined by a blinded independent review committee. Trial registered at ClinicalTrials.gov (NCT02306330). RESULTS: Among 1005 randomised patients, pathogens were isolated from 628 (326 intervention, 302 control), with 377 excluded as likely contaminants or discharged/died before positive culture. Most isolates were cultured from blood (421/628, 67.0%). The proportion receiving optimal antimicrobial therapy within 24 h (the primary outcome) or 48 h of growth was not significantly different between MALDITOF-MS and control arms (135/326, 41.4% vs 120/302, 39.7%; Adjusted Odds ration (AOR) 1.17, p = 0.40 and 151/326, 46.3% vs 141/302, 46.7%; AOR 1.05 p = 0.79, respectively). CONCLUSIONS: MALDITOF-MS, in the absence of an antimicrobial stewardship programme, did not improve the proportion on optimal antimicrobial therapy at 24 or 48 h after first growth in a lower-middle income setting with high rates of antibiotic resistance.


Subject(s)
Bacteremia/drug therapy , Bacteria/isolation & purification , Fungi/isolation & purification , Microbiological Techniques , Mycoses/drug therapy , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Adult , Anti-Bacterial Agents/therapeutic use , Antifungal Agents/therapeutic use , Bacteremia/diagnosis , Bacteremia/microbiology , Bacteria/drug effects , Female , Fungi/drug effects , Humans , Male , Middle Aged , Mycoses/diagnosis , Mycoses/microbiology , Prospective Studies , Time Factors , Treatment Outcome , Vietnam
12.
Wellcome Open Res ; 4: 8, 2019.
Article in English | MEDLINE | ID: mdl-30801037

ABSTRACT

Background: Cryptococcal meningitis is a leading cause of death in HIV-infected patients. International treatment guidelines recommend induction therapy with amphotericin B and flucytosine. This antifungal combination is most effective, but unfortunately flucytosine is expensive and unavailable where the burden of disease is greatest. Where unavailable, guidelines recommend treatment with amphotericin and fluconazole, but this is less effective, with mortality rates of 40-50%. Faster rates of clearance of yeast from cerebrospinal fluid (CSF) are associated with better outcomes - improving the potency of antifungal therapy is likely to be an effective strategy to improve survival. Tamoxifen, a selective estrogen receptor modulator used to treat breast cancer, has anti-cryptococcal activity, appearing synergistic when combined in vitro with amphotericin, and fungicidal when combined with fluconazole. It is concentrated in the brain and macrophages, off-patent, cheap and widely available. We designed a randomized trial to deliver initial efficacy and safety data for tamoxifen combined with amphotericin and fluconazole. Method: A phase II, open-label, randomized (1:1) controlled trial of tamoxifen (300mg/day) combined with amphotericin (1mg/kg/day) and fluconazole (800mg/day) for the first 2 weeks therapy for HIV infected or uninfected adults with cryptococcal meningitis. The study recruits at Cho Ray Hospital and the Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. The primary end point is Early Fungicidal Activity (EFA-the rate of yeast clearance from CSF), over the first two weeks of treatment. 50 patients will be recruited providing ≈80% and 90% power to detect a difference in the EFA of -0.11 or -0.13 log10CFU/ml/day, respectively. Discussion: The results of the study will inform the decision to proceed to a larger trial powered to mortality. The size of effect detectable has previously been associated with reduced mortality from this devastating disease. Particular side effects of interest include QT prolongation. Trial registration: Clinicaltrials.gov NCT03112031 (11/04/2017).

13.
Wellcome Open Res ; 3: 32, 2018.
Article in English | MEDLINE | ID: mdl-30363837

ABSTRACT

Background: Tuberculosis kills more people than any other bacterial infection worldwide. In tuberculous meningitis (TBM), a common functional promoter variant (C/T transition) in the gene encoding leukotriene A4 hydrolase (LTA4H), predicts pre-treatment inflammatory phenotype and response to dexamethasone in HIV-uninfected individuals. The primary aim of this study is to determine whether LTA4H genotype determines benefit or harm from adjunctive dexamethasone in HIV-uninfected Vietnamese adults with TBM. The secondary aim is to investigate alternative management strategies in individuals who develop drug induced liver injury (DILI) that will enable the safe continuation of rifampicin and isoniazid therapy.  Methods: We will perform a parallel group, randomised (1:1), double blind, placebo-controlled,  multi-centre Phase III non-inferiority trial, comparing dexamethasone versus placebo for 6-8 weeks in addition to standard anti-tuberculosis treatment in HIV-uninfected patients with TBM stratified by LTA4H genotype. The primary endpoint will be death or new neurological event. The trial will enrol approximately 720 HIV-uninfected adults with a clinical diagnosis of TBM, from two hospitals in Ho Chi Minh City, Vietnam. 640 participants with CC or CT- LTA4H genotype will be randomised to either dexamethasone or placebo, and the remaining TT- genotype participants will be treated with standard-of-care dexamethasone. We will also perform a randomised comparison of three management strategies for anti-tuberculosis DILI. An identical ancillary study will also be perfomed in the linked randomised controlled trial of dexamethasone in HIV-infected adults with TBM (ACT HIV).  Discussion: Previous data have shown that LTA4H genotype may be a critical determinant of inflammation and consequently of adjunctive anti-inflammatory treatment response in TBM. We will stratify dexamethasone therapy according to LTA4H genotype in HIV-uninfected adults, which may indicate a role for targeted anti-inflammatory therapy according to variation in LTA4H C/T transition. A comparison of DILI management strategies may allow the safe continuation of rifampicin and isoniazid.

14.
Wellcome Open Res ; 3: 31, 2018.
Article in English | MEDLINE | ID: mdl-30320225

ABSTRACT

Background: Tuberculous meningitis (TBM) is the most severe form of tuberculosis. Co-infection with HIV increases the risk of developing TBM, complicates treatment, and substantially worsens outcome. Whether corticosteroids confer a survival benefit in HIV-infected patients with TBM remains uncertain. Hepatitis is the most common drug-induced serious adverse event associated with anti-tuberculosis treatment, occurring in 20% of HIV-infected patients. The suggested concentration thresholds for stopping anti-tuberculosis drugs are not evidence-based. This study aims to determine whether dexamethasone is a safe and effective addition to the first 6-8 weeks of anti-tuberculosis treatment of TBM in patients with HIV, and investigate alternative management strategies in a subset of patients who develop drug induced liver injury (DILI) that will enable the safe continuation of rifampicin and isoniazid therapy.  Methods: We will perform a parallel group, randomised (1:1), double blind, placebo-controlled multi-centre Phase III trial, comparing the effect of dexamethasone versus placebo on overall survival in HIV-infected patients with TBM, in addition to standard anti-tuberculosis and antiretroviral treatment. The trial will be set in two hospitals in Ho Chi Minh City, Vietnam, and two hospitals in Jakarta, Indonesia. The trial will enrol 520 HIV-infected adults. An ancillary study will perform a randomised comparison of three DILI management strategies with the aim of demonstrating which strategy results in the least interruption in rifampicin and isoniazid treatment. An identical ancillary study will also be performed in the linked randomised controlled trial of dexamethasone in HIV-uninfected adults with TBM stratified by LTA4H genotype (LAST ACT).  Discussion: Whether corticosteroids confer a survival benefit in HIV-infected patients remains uncertain, and the current evidence base for using corticosteroids in this context is limited. Interruptions in anti-tuberculosis chemotherapy is a risk factor for death from TBM. Alternative management strategies in DILI may allow the safe continuation of rifampicin and isoniazid therapy.

15.
BMC Infect Dis ; 18(1): 375, 2018 08 07.
Article in English | MEDLINE | ID: mdl-30086716

ABSTRACT

BACKGROUND: Dengue virus infection results in a broad spectrum of clinical outcomes, ranging from asymptomatic infection through to severe dengue. Although prior infection with another viral serotype, i.e. secondary dengue, is known to be an important factor influencing disease severity, current methods to determine primary versus secondary immune status during the acute illness do not consider the rapidly evolving immune response, and their accuracy has rarely been evaluated against an independent gold standard. METHODS: Two hundred and ninety-three confirmed dengue patients were classified as experiencing primary, secondary or indeterminate infections using plaque reduction neutralisation tests performed 6 months after resolution of the acute illness. We developed and validated regression models to differentiate primary from secondary dengue on multiple acute illness days, using Panbio Indirect IgG and in-house capture IgG and IgM ELISA measurements performed on over 1000 serial samples obtained during acute illness. RESULTS: Cut-offs derived for the various parameters demonstrated progressive change (positively or negatively) by day of illness. Using these time varying cut-offs it was possible to determine whether an infection was primary or secondary on single specimens, with acceptable performance. The model using Panbio Indirect IgG responses and including an interaction with illness day showed the best performance throughout, although with some decline in performance later in infection. Models based on in-house capture IgG levels, and the IgM/IgG ratio, also performed well, though conversely performance improved later in infection. CONCLUSIONS: For all assays, the best fitting models estimated a different cut-off value for different days of illness, confirming how rapidly the immune response changes during acute dengue. The optimal choice of assay will vary depending on circumstance. Although the Panbio Indirect IgG model performs best early on, the IgM/IgG capture ratio may be preferred later in the illness course.


Subject(s)
Asymptomatic Infections , Dengue Virus/immunology , Dengue/diagnosis , Dengue/immunology , Neutralization Tests , Acute Disease , Adolescent , Adult , Algorithms , Antibodies, Viral/analysis , Antibodies, Viral/blood , Child , Child, Preschool , Dengue/virology , Diagnosis, Differential , Disease Progression , Enzyme-Linked Immunosorbent Assay/methods , Enzyme-Linked Immunosorbent Assay/standards , Female , Humans , Immunocompromised Host/immunology , Immunoglobulin G/analysis , Immunoglobulin G/blood , Immunoglobulin M/analysis , Immunoglobulin M/blood , Male , Neutralization Tests/methods , Neutralization Tests/standards , Sensitivity and Specificity , Serogroup , Severe Dengue/diagnosis , Severe Dengue/immunology , Severe Dengue/virology , Severity of Illness Index , Sick Leave , Young Adult
16.
J Clin Oncol ; 36(23): 2395-2404, 2018 08 10.
Article in English | MEDLINE | ID: mdl-29856692

ABSTRACT

Purpose The GALLIUM study ( ClinicalTrials.gov identifier: NCT01332968) showed that obinutuzumab (GA101; G) significantly prolonged progression-free survival (PFS) in previously untreated patients with follicular lymphoma relative to rituximab (R) when combined with cyclophosphamide (C), doxorubicin, vincristine (V), and prednisone (P; CHOP); CVP; or bendamustine. This report focuses on the impact of chemotherapy backbone on efficacy and safety. Patients and Methods A total of 1,202 patients with previously untreated follicular lymphoma (grades 1 to 3a), advanced disease (stage III or IV, or stage II with tumor diameter ≥ 7 cm), Eastern Cooperative Oncology Group performance status 0 to 2, and requiring treatment were randomly assigned 1:1 to G 1,000 mg on days 1, 8, and 15 of cycle 1 and day 1 of subsequent cycles or R 375 mg/m2 on day 1 of each cycle, for six to eight cycles, depending on chemotherapy (allocated nonrandomly by center). Responding patients received G or R for 2 years or until disease progression. Results Baseline Follicular Lymphoma International Prognostic Index risk, bulky disease, and comorbidities differed by chemotherapy. After 41.1 months median follow-up, PFS (primary end point) was superior for G plus chemotherapy (overall hazard ratio [HR], 0.68; 95% CI, 0.54 to 0.87; P = .0016), with consistent results across chemotherapy backbones (bendamustine: HR, 0.63; 95% CI, 0.46 to 0.88; CHOP: HR, 0.72; 95% CI, 0.48 to 1.10; CVP: HR, 0.79; 95% CI, 0.42 to 1.47). Grade 3 to 5 adverse events, notably cytopenias, were most frequent with CHOP. Grade 3 to 5 infections and second neoplasms were most frequent with bendamustine, which was associated with marked and prolonged reductions in T-cell counts. Fatal events were more frequent in patients treated with bendamustine, possibly reflecting differences in patient risk profiles. Conclusion Improved PFS was observed for G plus chemotherapy for all three chemotherapy backbones. Safety profiles differed, although comparisons are confounded by nonrandom chemotherapy allocation.


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Lymphoma, Follicular/drug therapy , Rituximab/administration & dosage , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal, Humanized/adverse effects , Antineoplastic Agents, Immunological/adverse effects , Antineoplastic Agents, Immunological/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bendamustine Hydrochloride/administration & dosage , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Doxorubicin/administration & dosage , Doxorubicin/adverse effects , Female , Humans , Male , Middle Aged , Prednisone/administration & dosage , Prednisone/adverse effects , Progression-Free Survival , Rituximab/adverse effects , Vincristine/administration & dosage , Vincristine/adverse effects , Young Adult
17.
Trials ; 19(1): 217, 2018 Apr 04.
Article in English | MEDLINE | ID: mdl-29615093

ABSTRACT

BACKGROUND: Ventilator-associated respiratory infection (VARI) comprises ventilator-associated pneumonia (VAP) and ventilator-associated tracheobronchitis (VAT). Although their diagnostic criteria vary, together these are the most common hospital-acquired infections in intensive care units (ICUs) worldwide, responsible for a large proportion of antibiotic use within ICUs. Evidence-based strategies for the prevention of VARI in resource-limited settings are lacking. Preventing the leakage of oropharyngeal secretions into the lung using continuous endotracheal cuff pressure control is a promising strategy. The aim of this study is to investigate the efficacy of automated, continuous endotracheal cuff pressure control in preventing the development of VARI and reducing antibiotic use in ICUs in Vietnam. METHODS/DESIGN: This is an open-label randomised controlled multicentre trial. We will enrol 600 adult patients intubated for ≤ 24 h at the time of enrolment. Eligible patients will be stratified according to admission diagnosis (180 tetanus, 420 non-tetanus) and site and will be randomised in a 1:1 ratio to receive either (1) automated, continuous control of endotracheal cuff pressure or (2) intermittent measurement and control of endotracheal cuff pressure using a manual cuff pressure meter. The primary outcome is the occurrence of VARI, defined as either VAP or VAT during the ICU admission up to a maximum of 90 days after randomisation. Patients in both groups who are at risk for VARI will receive a standardised battery of investigations if their treating physician feels a new infection has occurred, the results of which will be used by an endpoint review committee, blinded to the allocated arm and independent of patient care, to determine the primary outcome. All enrolled patients will be followed for mortality and endotracheal tube cuff-related complications at 28 days and 90 days after randomisation. Other secondary outcomes include antibiotic use; days ventilated, in ICU and in hospital; inpatient mortality; costs of antibiotics in ICU; duration of ICU stay; and duration of hospital stay. DISCUSSION: This study will provide high-quality evidence concerning the use of continuous endotracheal cuff pressure control as a method to reduce VARI, antibiotic use and hospitalisation costs and to shorten stay. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02966392 . Registered on November 9, 2016. Protocol version: 2.0; issue date March 3, 2017.


Subject(s)
Bronchitis/prevention & control , Intubation, Intratracheal/adverse effects , Pneumonia, Ventilator-Associated/prevention & control , Respiration, Artificial/adverse effects , Tracheitis/prevention & control , Ventilators, Mechanical/adverse effects , Anti-Bacterial Agents/therapeutic use , Bronchitis/diagnosis , Bronchitis/etiology , Bronchitis/mortality , Equipment Design , Hospital Mortality , Humans , Intubation, Intratracheal/instrumentation , Intubation, Intratracheal/mortality , Length of Stay , Multicenter Studies as Topic , Pneumonia, Ventilator-Associated/diagnosis , Pneumonia, Ventilator-Associated/etiology , Pneumonia, Ventilator-Associated/mortality , Randomized Controlled Trials as Topic , Respiration, Artificial/instrumentation , Respiration, Artificial/mortality , Risk Factors , Time Factors , Tracheitis/diagnosis , Tracheitis/etiology , Tracheitis/mortality , Treatment Outcome , Vietnam
18.
Elife ; 72018 02 27.
Article in English | MEDLINE | ID: mdl-29482717

ABSTRACT

Adjunctive dexamethasone reduces mortality from tuberculous meningitis (TBM) but not disability, which is associated with brain infarction. We hypothesised that aspirin prevents TBM-related brain infarction through its anti-thrombotic, anti-inflammatory, and pro-resolution properties. We conducted a randomised controlled trial in HIV-uninfected adults with TBM of daily aspirin 81 mg or 1000 mg, or placebo, added to the first 60 days of anti-tuberculosis drugs and dexamethasone (NCT02237365). The primary safety endpoint was gastro-intestinal or cerebral bleeding by 60 days; the primary efficacy endpoint was new brain infarction confirmed by magnetic resonance imaging or death by 60 days. Secondary endpoints included 8-month survival and neuro-disability; the number of grade 3 and 4 and serious adverse events; and cerebrospinal fluid (CSF) inflammatory lipid mediator profiles. 41 participants were randomised to placebo, 39 to aspirin 81 mg/day, and 40 to aspirin 1000 mg/day between October 2014 and May 2016. TBM was proven microbiologically in 92/120 (76.7%) and baseline brain imaging revealed ≥1 infarct in 40/114 (35.1%) participants. The primary safety outcome occurred in 5/36 (13.9%) given placebo, and in 8/35 (22.9%) and 8/40 (20.0%) given 81 mg and 1000 mg aspirin, respectively (p=0.59). The primary efficacy outcome occurred in 11/38 (28.9%) given placebo, 8/36 (22.2%) given aspirin 81 mg, and 6/38 (15.8%) given 1000 mg aspirin (p=0.40). Planned subgroup analysis showed a significant interaction between aspirin treatment effect and diagnostic category (Pheterogeneity = 0.01) and suggested a potential reduction in new infarcts and deaths by day 60 in the aspirin treated participants with microbiologically confirmed TBM (11/32 (34.4%) events in placebo vs. 4/27 (14.8%) in aspirin 81 mg vs. 3/28 (10.7%) in aspirin 1000 mg; p=0.06). CSF analysis demonstrated aspirin dose-dependent inhibition of thromboxane A2 and upregulation of pro-resolving CSF protectins. The addition of aspirin to dexamethasone may improve outcomes from TBM and warrants investigation in a large phase 3 trial.


The deadliest form of tuberculosis is tuberculosis meningitis (TBM), which causes inflammation in the brain. Even with the best treatment available, about half of patients with TBM become disabled or die, often because they have a stroke. Strokes are caused by blood clots or other blockages in blood vessels in the brain. Aspirin is known to prevent blood clots and helps reduce inflammation. Some scientists wonder if it might help patients with TBM by preventing blockages in blood vessels. Now, Nguyen et al. show that adding aspirin to existing TBM treatments may reduce strokes in some patients. In the experiments, 120 patients with TBM were randomly assigned to receive a low dose of aspirin (81 mg/day), a high dose of aspirin (1000mg/day), or an identical tablet that contained no medication. All the patients also took the anti-tuberculosis drugs and steroids usually used to treat the condition. Both doses of aspirin appeared to be safe. Patients who received aspirin were less likely to have a stroke or die in the first two months of treatment than patients who received the fake pill. But the difference was so small it could have been caused by chance. In the 92 patients with clear evidence of tuberculosis bacteria in their brains, the benefit of aspirin was larger and unlikely to be due to chance. The benefit was greatest for those who received the higher dose of aspirin, only 10.7% of these patients died or had a stroke, compared with 14.8% of those who received a low dose of aspirin, or 34% of those who received the fake pill. Next, Nguyen et al. looked at brain fluid taken from the TBM patients before and after they received the aspirin or fake medication. The experiments showed that patients treated with high dose aspirin had much lower levels of a clot-promoting substance called thromboxane A2 and more anti-inflammatory molecules. Larger studies are needed in children and adults to confirm that aspirin helps prevent strokes or death in patients with TBM. Studies are also needed on patients who have both TBM and HIV infections. But if more studies show aspirin is safe and effective, adding this medication to TBM treatment may be an inexpensive way to prevent death or disability.


Subject(s)
Antitubercular Agents/administration & dosage , Aspirin/administration & dosage , Combined Modality Therapy/methods , Fibrinolytic Agents/administration & dosage , HIV Infections/complications , Tuberculosis, Meningeal/drug therapy , Adult , Antitubercular Agents/adverse effects , Aspirin/adverse effects , Combined Modality Therapy/adverse effects , Double-Blind Method , Drug-Related Side Effects and Adverse Reactions/epidemiology , Drug-Related Side Effects and Adverse Reactions/pathology , Female , Fibrinolytic Agents/adverse effects , Humans , Male , Mental Disorders/epidemiology , Mental Disorders/prevention & control , Middle Aged , Placebos/administration & dosage , Survival Analysis , Treatment Outcome
19.
BMJ Open ; 8(1): e016349, 2018 01 21.
Article in English | MEDLINE | ID: mdl-29358416

ABSTRACT

BACKGROUND: Acute respiratory tract infections (ARIs) are the leading cause of morbidity and mortality in young children in low/middle-income countries. Using routine hospital data, we aimed to examine the spatial distribution, temporal trends and climatic risk factors of paediatric ARIs in Vietnam. METHODS: Data from hospitalised paediatric (<16 years) patients with ARIs residing in Ho Chi Minh City (HCMC) between 2005 and 2010 were retrieved from the two main Children's Hospitals and the Hospital for Tropical Diseases in HCMC. Spatial mapping and time series analysis were performed after disaggregating data into upper respiratory tract infections (URIs) and lower respiratory tract infections (LRIs). RESULTS: Over the study period, there were 155 999 paediatric patients admitted with ARIs (33% of all hospital admissions). There were 68 120 URIs (14%) and 87 879 LRIs (19%). The most common diagnoses were acute pharyngitis (28% of all ARI), pneumonia (21%), bronchitis (18%) and bronchiolitis (16%). A significant increasing trend over time was found for both URIs (mean weekly incidence per 1000 population, I=3.12), incidence rate ratio for 1-week increase in time (RR 1.0, 95% CI 1.02 to 1.17) for URI and (I=4.02, RR 1.08 (95% CI 1.006 to 1.16)) for LRI. The weekly URI incidence peaked in May-June and was significantly associated with lags in weekly URI incidence and the average humidity, rainfall and water level. The weekly LRI incidence exhibited significant seasonality (P<0.0001), with an annual peak in September-October and was significantly associated with lags in weekly LRI incidence and lags in weekly average temperature, rainfall and water level. CONCLUSIONS: ARIs are a leading cause of childhood hospitalisation in HCMC, Vietnam. The incidence of ARIs was higher in the wet season and in specific HCMC districts. These results may guide health authorities in where and when to effectively allocate resources for the prevention and control of ARIs.


Subject(s)
Hospitalization/statistics & numerical data , Respiratory Tract Infections/epidemiology , Seasons , Weather , Acute Disease , Adolescent , Child , Child, Preschool , Female , Hospitals, Pediatric , Humans , Incidence , Infant , Infant, Newborn , Male , Retrospective Studies , Risk Factors , Spatio-Temporal Analysis , Vietnam/epidemiology
20.
Wellcome Open Res ; 3: 58, 2018.
Article in English | MEDLINE | ID: mdl-30809591

ABSTRACT

Despite long-standing availability of an effective vaccine, tetanus remains a significant problem in many countries. Outcome depends on access to mechanical ventilation and intensive care facilities and in settings where these are limited, mortality remains high. Administration of tetanus antitoxin by the intramuscular route is recommended treatment for tetanus, but as the tetanus toxin acts within the central nervous system, it has been suggested that intrathecal administration of antitoxin may be beneficial. Previous studies have indicated benefit, but with the exception of one small trial no blinded studies have been performed. The objective of this study is to establish whether the addition of intrathecal tetanus antitoxin reduces the need for mechanical ventilation in patients with tetanus. Secondary objectives: to determine whether the addition of intrathecal tetanus antitoxin reduces autonomic nervous system dysfunction and length of hospital/ intensive care unit stay; whether the addition of intrathecal tetanus antitoxin in the treatment of tetanus is safe and cost-effective; to provide data to inform recommendation of human rather than equine antitoxin. This study will enroll adult patients (≥16 years old) with tetanus admitted to the Hospital for Tropical Diseases, Ho Chi Minh City. The study is a 2x2 factorial blinded randomized controlled trial. Eligible patients will be randomized in a 1:1:1:1 manner to the four treatment arms (intrathecal treatment and human intramuscular treatment, intrathecal treatment and equine intramuscular treatment, sham procedure and human intramuscular treatment, sham procedure and equine intramuscular treatment). Primary outcome measure will be requirement for mechanical ventilation. Secondary outcome measures: duration of hospital/ intensive care unit stay, duration of mechanical ventilation, in-hospital and 240-day mortality and disability, new antibiotic prescription, incidence of ventilator associated pneumonia and autonomic nervous system dysfunction, total dose of benzodiazepines and pipecuronium, and incidence of adverse events. Trial registration: ClinicalTrials.gov NCT02999815 Registration date: 21 December 2016.

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