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Evidence from randomized controlled trials available for timely health technology assessments of new pharmacological treatments and regulatory decision making may not be generalizable to local patient populations, often resulting in decisions being made under uncertainty. In recent years, several reweighting approaches have been explored to address this important question of generalizability to a target population. We present a case study of the Innovative Medicines Initiative to illustrate the inverse propensity score reweighting methodology, which may allow us to estimate the expected treatment benefit if a clinical trial had been run in a broader real‐world target population. We learned that identifying treatment effect modifiers, understanding and managing differences between patient characteristic data sets, and balancing the closeness of trial and target patient populations with effective sample size are key to successfully using this methodology and potentially mitigating some of this uncertainty around local decision making. [ABSTRACT FROM AUTHOR]

Background: Early diagnosis of Alzheimer's disease (AD) is crucial to implement the latest treatment strategies and management of AD symptoms. Diagnostic procedures play a major role in this detection process but evidence on their respective accuracy is still limited. Objective: To conduct a systematic literature on the sensitivity and specificity of different test modalities to identify AD patients and perform meta-analyses on the test accuracy values of studies focusing on autopsy-confirmation as the standard of truth. Methods: The systematic review identified all English papers published between 1984 and 2011 on diagnostic imaging tests and cerebrospinal fluid biomarkers including results on the newest technologies currently investigated in this area. Meta-analyses using bivariate fixed and random-effect models and hierarchical summary receiver operating curve (HSROC) random-effect model were applied. Results: Out of the 1,189 records, 20 publications were identified to report the accuracy of diagnostic tests in distinguishing autopsy-confirmed AD patients from other dementia types and healthy controls. Looking at all tests and comparator populations together, sensitivity was calculated at 85.4% (95% confidence interval [CI]: 80.9%-90.0%) and specificity at 77.7% (95% CI: 70.2%-85.1%). The area under the HSROC curve was 0.88. Sensitivity and specificity values were higher for imaging procedures, and slightly lower for CSF biomarkers. Test-specific random-effect models could not be calculated due to the small number of studies. Conclusion: The review and meta-analysis point to a slight advantage of imaging procedures in correctly detecting AD patients but also highlight the limited evidence on autopsy-confirmations and heterogeneity in study designs. [ABSTRACT FROM AUTHOR]

Background: The rising prevalence of Alzheimer's disease (AD), and other diseases associated with dementia, imposes significant burden to various stakeholders who care for the elderly. Management of AD is complicated by multiple factors including disease-specific features which make it difficult to diagnose accurately during milder stages. Florbetapir F18 positron emission tomography (florbetapir-PET) is an approved imaging tool used to capture beta-amyloid neuritic plaque density in brains of cognitively impaired adults undergoing evaluation for AD and other causes of cognitive impairment. It has the potential to help improve healthcare outcomes as it may help clinicians identify patients with AD early so that treatments are initiated when most effective., Aims of the Study: Evaluate the potential long-term clinical and economic outcomes of adopting florbetapir-PET--adjunctive to standard clinical evaluation (SCE)--versus SCE alone in the diagnostic assessment of cognitively impaired patients with suspected AD., Methods: A decision analysis with a ten-year time horizon was developed in compliance with Good Research Practices and CHEERS guidelines. The target population was comprised of Spanish patients who were undergoing initial assessment for cognitive impairment (Mini-Mental State Examination [MMSE] score=20). Diagnostic accuracy, rate of cognitive decline, effect of drugs on cognition and dwelling status, economic burden (direct and indirect costs), and quality of life (QoL) were based on relevant clinical studies and published literature. Scenario analysis was applied to explore outcomes under different conditions, which included: (i) use of florbetapir-PET earlier in disease progression (MMSE score=22); and (ii) the addition of fluorodeoxyglucose (FDG)-PET to SCE., Results: Adjunctive florbetapir-PET increased quality-adjusted life years (QALYs) by 0.008 years and increased costs by 36 compared to SCE alone (incremental cost-effectiveness ratio [ICER], 4,769). Use of florbetapir-PET was dominant in alternate scenarios. Sensitivity analyses indicated rates of institutionalization (by MMSE) and MMSE score upon initiation of acetylcholinesterase inhibitor (AChEI) treatment most influenced the primary outcome (ICER) in the base case scenario. Over 82% of probabilistic simulations were cost-effective using the Spanish threshold (30,000/QALY)., Discussion: The addition of florbetapir-PET to SCE is expected to improve the accuracy of AD diagnoses for patients experiencing cognitive impairment; it is cost-effective due to decreased healthcare costs and caregiver burden. Prospective studies of the clinical utility of florbetapir-PET are necessary to evaluate the long-term implications of adopting florbetapir-PET on clinical outcomes and costs in real-world settings., Implications for Health Care Provision and Use: Florbetapir-PET is expected to improve decision-making regarding appropriate and sufficient care for cognitively impaired patients with suspected AD, while cost-effective., Implications for Health Policies: Earlier and more accurate diagnosis of AD may help to improve patient's health status and reduce treatment costs by effectively allocating healthcare resources and maximizing the benefit of treatments and supportive services., Implications for Further Research: Use of florbetapir-PET may help accurately identify patients with AD. The development of novel therapeutics for use with companion diagnostics may provide additional benefits by slowing or halting progressive cognitive decline with AD, increase QoL and prolong survival.