Controlled multiple imputation methods for sensitivity analyses in longitudinal clinical trials with dropout and protocol deviation

2015 ◽  
Vol 5 (3) ◽  
pp. 311-320 ◽  
Author(s):  
Michael G Kenward
Keyword(s):  
Clinical Trials ◽  
Multiple Imputation ◽  
Sensitivity Analyses ◽  
Imputation Methods ◽  
Protocol Deviation

A Multiple-Imputation-Based Approach to Sensitivity Analyses and Effectiveness Assessments in Longitudinal Clinical Trials

2014 ◽  
Vol 24 (2) ◽  
pp. 211-228 ◽  
Author(s):  
Birhanu Teshome Ayele ◽  
Ilya Lipkovich ◽  
Geert Molenberghs ◽  
Craig H. Mallinckrodt
Keyword(s):  
Clinical Trials ◽  
Multiple Imputation ◽  
Sensitivity Analyses

Stroke Prevention in Non-Valvular Atrial Fibrillation

1997 ◽  
Vol 17 (03) ◽  
pp. 166-169
Author(s):  
Judith O’Brien ◽  
Wendy Klittich ◽  
J. Jaime Caro
Keyword(s):  
Atrial Fibrillation ◽  
Clinical Trials ◽  
Care Home ◽  
Relevant Literature ◽  
Clinical Trial Data ◽  
Outcome Data ◽  
Sensitivity Analyses ◽  
Bleeding Events ◽  
Discharge Data ◽  
The Cost

SummaryDespite evidence from 6 major clinical trials that warfarin effectively prevents strokes in atrial fibrillation, clinicians and health care managers may remain reluctant to support anticoagulant prophylaxis because of its perceived costs. Yet, doing nothing also has a price. To assess this, we carried out a pharmacoe-conomic analysis of warfarin use in atrial fibrillation. The course of the disease, including the occurrence of cerebral and systemic emboli, intracranial and other major bleeding events, was modeled and a meta-analysis of the clinical trials and other relevant literature was carried out to estimate the required probabilities with and without warfarin use. The cost of managing each event, including acute and subsequent care, home care equipment and MD costs, was derived by estimating the cost per resource unit, the proportion consuming each resource and the volume of use. Unit costs and volumes of use were determined from established US government databases, all charges were adjusted using cost-to-charge ratios, and a 3% discount rate was applied to costs incurred beyond the first year. The proportions of patients consuming each resource were estimated by fitting a joint distribution to the clinical trial data, stroke outcome data from a recent Swedish study and aggregate ICD-9 specific, Massachusetts discharge data. If nothing is done, 3.2% more patients will suffer serious emboli annually and the expected annual cost of managing a patient will increase by DM 2,544 (1996 German Marks), from DM 4,366 to DM 6,910. Extensive multiway sensitivity analyses revealed that the higher price of doing nothing persists except for very extreme combinations of inputs unsupported by literature or clinical standards. The price of doing nothing is thus so high, both in health and economic terms, that cost-consciousness as well as clinical considerations mandate warfarin prophylaxis in atrial fibrillation.

scholarly journals Results availability and timeliness of registered COVID-19 clinical trials: interim cross-sectional results from the DIRECCT study

BMJ Open ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. e053096
Author(s):  
Maia Salholz-Hillel ◽  
Peter Grabitz ◽  
Molly Pugh-Jones ◽  
Daniel Strech ◽  
Nicholas J DeVito
Keyword(s):  
Clinical Trial ◽  
Clinical Trials ◽  
Journal Article ◽  
Cross Sectional Study ◽  
Sensitivity Analyses ◽  
Cross Sectional ◽  
Registration Data ◽  
Clinical Trial Registries ◽  
Treatment And Prevention

ObjectiveTo examine how and when the results of COVID-19 clinical trials are disseminated.DesignCross-sectional study.SettingThe COVID-19 clinical trial landscape.Participants285 registered interventional clinical trials for the treatment and prevention of COVID-19 completed by 30 June 2020.Main outcome measuresOverall reporting and reporting by dissemination route (ie, by journal article, preprint or results on a registry); time to reporting by dissemination route.ResultsFollowing automated and manual searches of the COVID-19 literature, we located 41 trials (14%) with results spread across 47 individual results publications published by 15 August 2020. The most common dissemination route was preprints (n=25) followed by journal articles (n=18), and results on a registry (n=2). Of these, four trials were available as both a preprint and journal publication. The cumulative incidence of any reporting surpassed 20% at 119 days from completion. Sensitivity analyses using alternate dates and definitions of results did not appreciably change the reporting percentage. Expanding minimum follow-up time to 3 months increased the overall reporting percentage to 19%.ConclusionCOVID-19 trials completed during the first 6 months of the pandemic did not consistently yield rapid results in the literature or on clinical trial registries. Our findings suggest that the COVID-19 response may be seeing quicker results disclosure compared with non-emergency conditions. Issues with the reliability and timeliness of trial registration data may impact our estimates. Ensuring registry data are accurate should be a priority for the research community during a pandemic. Data collection is underway for the next phase of the DIssemination of REgistered COVID-19 Clinical Trials study expanding both our trial population and follow-up time.

scholarly journals A systematic review and economic evaluation of adalimumab and dexamethasone for treating non-infectious intermediate uveitis, posterior uveitis or panuveitis in adults

2017 ◽  
Vol 21 (68) ◽  
pp. 1-170 ◽  
Author(s):  
Hazel Squires ◽  
Edith Poku ◽  
Inigo Bermejo ◽  
Katy Cooper ◽  
John Stevens ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Cost Effectiveness ◽  
Current Practice ◽  
Clinical Effectiveness ◽  
Posterior Uveitis ◽  
Sensitivity Analyses ◽  
Dexamethasone Implant ◽  
Intermediate Uveitis ◽  
Sham Procedure ◽  
The Cost

BackgroundNon-infectious intermediate uveitis, posterior uveitis and panuveitis are a heterogeneous group of inflammatory eye disorders. Management includes local and systemic corticosteroids, immunosuppressants and biological drugs.ObjectivesTo evaluate the clinical effectiveness and cost-effectiveness of subcutaneous adalimumab (Humira®; AbbVie Ltd, Maidenhead, UK) and a dexamethasone intravitreal implant (Ozurdex®; Allergan Ltd, Marlow, UK) in adults with non-infectious intermediate uveitis, posterior uveitis or panuveitis.Data sourcesElectronic databases and clinical trials registries including MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and the World Health Organization’s International Clinical Trials Registry Platform were searched to June 2016, with an update search carried out in October 2016.Review methodsReview methods followed published guidelines. A Markov model was developed to assess the cost-effectiveness of dexamethasone and adalimumab, each compared with current practice, from a NHS and Personal Social Services (PSS) perspective over a lifetime horizon, parameterised with published evidence. Costs and benefits were discounted at 3.5%. Substantial sensitivity analyses were undertaken.ResultsOf the 134 full-text articles screened, three studies (four articles) were included in the clinical effectiveness review. Two randomised controlled trials (RCTs) [VISUAL I (active uveitis) and VISUAL II (inactive uveitis)] compared adalimumab with placebo, with limited standard care also provided in both arms. Time to treatment failure (reduced visual acuity, intraocular inflammation, new vascular lesions) was longer in the adalimumab group than in the placebo group, with a hazard ratio of 0.50 [95% confidence interval (CI) 0.36 to 0.70;p < 0.001] in the VISUAL I trial and 0.57 (95% CI 0.39 to 0.84;p = 0.004) in the VISUAL II trial. The adalimumab group showed a significantly greater improvement than the placebo group in the 25-item Visual Function Questionnaire (VFQ-25) composite score in the VISUAL I trial (mean difference 4.20;p = 0.010) but not the VISUAL II trial (mean difference 2.12;p = 0.16). Some systemic adverse effects occurred more frequently with adalimumab than with placebo. One RCT [HURON (active uveitis)] compared a single 0.7-mg dexamethasone implant against a sham procedure, with limited standard care also provided in both arms. Dexamethasone provided significant benefits over the sham procedure at 8 and 26 weeks in the percentage of patients with a vitreous haze score of zero (p < 0.014), the mean best corrected visual acuity improvement (p ≤ 0.002) and the percentage of patients with a ≥ 5-point improvement in VFQ-25 score (p < 0.05). Raised intraocular pressure and cataracts occurred more frequently with dexamethasone than with the sham procedure. The incremental cost-effectiveness ratio (ICER) for one dexamethasone implant in one eye for a combination of patients with unilateral and bilateral uveitis compared with limited current practice, as per the HURON trial, was estimated to be £19,509 per quality-adjusted life-year (QALY) gained. The ICER of adalimumab for patients with mainly bilateral uveitis compared with limited current practice, as per the VISUAL trials, was estimated to be £94,523 and £317,547 per QALY gained in active and inactive uveitis respectively. Sensitivity analyses suggested that the rate of blindness has the biggest impact on the model results. The interventions may be more cost-effective in populations in which there is a greater risk of blindness.LimitationsThe clinical trials did not fully reflect clinical practice. Thirteen additional studies of clinically relevant comparator treatments were identified; however, network meta-analysis was not feasible. The model results are highly uncertain because of the limited evidence base.ConclusionsTwo RCTs of systemic adalimumab and one RCT of a unilateral, single dexamethasone implant showed significant benefits over placebo or a sham procedure. The ICERs for adalimumab were estimated to be above generally accepted thresholds for cost-effectiveness. The cost-effectiveness of dexamethasone was estimated to fall below standard thresholds. However, there is substantial uncertainty around the model assumptions. In future work, primary research should compare dexamethasone and adalimumab with current treatments over the long term and in important subgroups and consider how short-term improvements relate to long-term effects on vision.Study registrationThis study is registered as PROSPERO CRD42016041799.FundingThe National Institute for Health Research Health Technology Assessment programme.

Cost-effectiveness analysis of neoadjuvant immune checkpoint inhibition (ICI) versus cisplatin-based chemotherapy (CBC) in muscle-invasive bladder cancer (MIBC).

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 419-419
Author(s):  
Ali Raza Khaki ◽  
Yong Shan ◽  
Richard Nelson ◽  
Sapna Kaul ◽  
John L. Gore ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Cost Effectiveness ◽  
Incremental Cost ◽  
Randomized Clinical Trials ◽  
Pathologic Complete Response ◽  
Weighted Average ◽  
Cost Effective ◽  
Cost Effectiveness Analysis ◽  
Sensitivity Analyses ◽  
Effectiveness Analysis

419 Background: Multiple single-arm clinical trials have shown promising pathologic complete response (pCR) rates with neoadjuvant ICIs in MIBC. However, ICIs remain costly. We conducted a cost-effectiveness analysis comparing neoadjuvant ICIs with CBC. Methods: We applied a decision analytic simulation model with a health care payer perspective and two-year time horizon to compare neoadjuvant ICIs vs CBC. For the primary analysis we compared pembrolizumab with dose dense methotrexate, vinblastine, doxorubicin, and cisplatin (ddMVAC). We performed a secondary analysis with gemcitabine/cisplatin (GC) as CBC and exploratory analyses with atezolizumab or nivolumab/ipilimumab as ICIs (vs both ddMVAC and GC). We input pCR rates from trials (ICIs) or a weighted average of prior studies (CBC) and costs from average sales price. Outcomes of interest included costs, 2-year recurrence-free survival (RFS), and incremental cost-effectiveness ratio (ICER) of cost per 2-year RFS. A threshold analysis estimated a pCR rate or price reduction for ICI to be cost-effective and one-way and probabilistic sensitivity analyses were performed. Results: Results of the cost effectiveness analysis are shown in the table. The incremental cost of pembrolizumab compared with ddMVAC was $8,042 resulting in an incremental improvement of 0.66% in 2-year RFS for an ICER of $1,218,485 per 2-year RFS. A pCR of 71% or a 26% reduction in cost of pembrolizumab would render it more cost-effective with an ICER of $100,000 per 2-year RFS. GC required a 96% pembrolizumab cost reduction to achieve an ICER of $100,000 per 2-year RFS. Atezolizumab appeared to be more cost-effective than ddMVAC, even though the 2yr RFS was 0.66% worse. Conclusions: ICIs were not cost-effective as neoadjuvant therapies, except when atezolizumab was compared with ddMVAC. Pembrolizumab would approach cost-effective thresholds with 26% or 96% reduction in cost when compared to ddMVAC and GC, respectively. Randomized clinical trials, larger sample sizes and longer follow-up are required to better understand the value of ICIs as neoadjuvant treatments. [Table: see text]

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