Matching Methods for Causal Inference: A Review and a Look Forward

When estimating causal effects using observational data, it is desirable to replicate a randomized experiment as closely as possible by obtaining treated and control groups with similar covariate distributions. This goal can often be achieved by choosing well-matched samples of the original treated and control groups, thereby reducing bias due to the covariates. Since the 1970s, work on matching methods has examined how to best choose treated and control subjects for comparison. Matching methods are gaining popularity in fields such as economics, epidemiology, medicine and political science. However, until now the literature and related advice has been scattered across disciplines. Researchers who are interested in using matching methods---or developing methods related to matching---do not have a single place to turn to learn about past and current research. This paper provides a structure for thinking about matching methods and guidance on their use, coalescing the existing research (both old and new) and providing a summary of where the literature on matching methods is now and where it should be headed.Comment: Published in at http://dx.doi.org/10.1214/09-STS313 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Cardiac myosin-specific autoimmune T cells contribute to immune-checkpoint-inhibitor-associated myocarditis

Immune checkpoint inhibitors (ICIs) are an effective therapy for various cancers; however, they can induce immune-related adverse events (irAEs) as a side effect. Myocarditis is an uncommon, but fatal, irAE caused after ICI treatments. Currently, the mechanism of ICI-associated myocarditis is unclear. Here, we show the development of myocarditis in A/J mice induced by anti-PD-1 monoclonal antibody (mAb) administration alone without tumor cell inoculation, immunization, or viral infection. Mice with myocarditis have increased cardiac infiltration, elevated cardiac troponin levels, and arrhythmia. Anti-PD-1 mAb treatment also causes irAEs in other organs. Autoimmune T cells recognizing cardiac myosin are activated and increased in mice with myocarditis. Notably, cardiac myosin-specific T cells are present in naive mice, showing a phenotype of antigen-experienced T cells. Collectively, we establish a clinically relevant mouse model for ICI-associated myocarditis and find a contribution of cardiac myosin-specific T cells to ICI-associated myocarditis development and pathogenesi

The teen years explained: a guide to healthy adolescent development

1. Physical Development -- 2. Cognitive Development -- 3. Emotional & Social Development -- 4. Forming an Identity -- 5. Sexuality -- 6. Spirituality & Religion -- 7. Profiles of Development -- 8. Conclusion -- Resources & Further Reading -- Referencesby Clea McNeely and Jayne Blanchard ; with a foreword by Nicole Yohalem, Karen PittmanAlso available via the World Wide Web.Includes bibliographical references (p. 94-102) and index.The Guide was made possible by funding from the Centers for Disease Control and Prevention (CDC) to the Center for Adolescent Health at the Johns Hopkins Bloomberg School of Public Health, a member of the Prevention Research Centers Program, CDC cooperative agreement 1-U48-DP-000040

Understanding community health volunteer incentive preferences in Kenya

In Kenya, community health services are implemented through community health units. Community health volunteers (CHVs) who serve these units are chosen by the community and trained by community health extension workers. This brief summarizes qualitative and quantitative findings from the Frontline Health project’s discrete choice experiment study in Kenya, which aimed to understand incentive preferences of CHVs with the aim of improving motivation, performance, and retention of CHVs

Preferred incentives for improving community health worker satisfaction and retention in Bangladesh

Community health workers (CHWs) are critical actors within community health systems, providing a range of reproductive, maternal, child, and primary health information, counseling, and services. To better understand factors that influence CHWs’ work motivation and satisfaction in Bangladesh, the Frontline Health project, implemented with collaborators from Johns Hopkins Bloomberg School of Public Health, and supported by the government of Bangladesh’s Directorate General of Health Services and the Directorate General of Family Planning, conducted a discrete choice experiment (DCE) study. This brief presents key qualitative findings from the DCE study in Bangladesh and implications for program and policy stakeholders

Identifying factors that support community health worker motivation, job satisfaction, and retention in Haiti

Community health workers (CHWs) play a critical role in Haiti’s health system, by connecting communities—particularly rural and hard-to-reach populations—to healthcare services. The Frontline Health project conducted a study to better understand the types of incentive structures that can best support the CHWs in Haiti and this brief summarizes those findings

Costs of Military Eye Injury, Vision Impairment, and Related Blindness and Vision Dysfunction Associated with Traumatic Brain Injury (TBI) without Eye Injury Prepared by

2 TAKE AWAY MESSAGE Based on published data from 2000-2010, the total incident cost of eye injury in the military each year in this timeframe has been $2.282 billion, which represents superficial eye injury, nonsuperficial eye injury that does and does not result in permanent visual impairment or blindness, and vision impairment related to Traumatic Brain Injury (TBI). If we multiply the one-year costs by 11 to account for the period from 2000-2010, the total cost to the economy of all ocular injury and vision impairment related to TBI is$25.107 billion. Of that total, the costs incurred in the first year (all for superficial injury, initial medical care for non-superficial injuries, and rehabilitation for bilateral vision impairment) are $634 million. This is money that has already been spent. The present value of the projected Department of Veterans Affairs (VA) benefits for the remainder of the lives of all service members with ocular injuries in the 11 years under study is$188 million. The present value of the projected costs to the remainder of the economy over the remaining lifetimes of the service members with eye injuries or vision impairment due to TBI is $24.286 billion. This last cost is not to the federal government but to the economy and society as a whole

The pace of governed energy transitions: agency, international dynamics and the global Paris agreement accelerating decarbonisation processes?

The recent debate on the temporal dynamics of energy transitions is crucial since one of the main reasons for embarking on transitions away from fossil fuels is tackling climate change. Long-drawn out transitions, taking decades or even centuries as we have seen historically, are unlikely to help achieve climate change mitigation targets. Therefore, the pace of energy transitions and whether they can be sped up is a key academic and policy question. Our argument is that while history is important in order to understand the dynamics of transitions, the pace of historic transitions is only partly a good guide to the future. We agree with Sovacool’s [1] argument that quicker transitions have happened in the past and may therefore also be possible in the future globally. The key reason for our optimism is that historic energy transitions have not been consciously governed, whereas today a wide variety of actors is engaged in active attempts to govern the transition towards low carbon energy systems. In addition, international innovation dynamics can work in favour of speeding up the global low-carbon transition. Finally, the 2015 Paris agreement demonstrates a global commitment to move towards a low carbon economy for the first time, thereby signalling the required political will to foster quick transitions and to overcome resistance, such as from incumbents with sunk infrastructure investments

Comparison of alternative risk adjustment measures for predictive modeling: high risk patient case finding using Taiwan's National Health Insurance claims

<p>Abstract</p> <p>Background</p> <p>Predictive modeling presents an opportunity to contain the expansion of medical expenditures by focusing on very few people. Evaluation of how risk adjustment models perform in predictive modeling in Taiwan or Asia has been rare. The aims of this study were to evaluate the performance of different risk adjustment models (the ACG risk adjustment system and prior expenditures) in predictive modeling, using Taiwan's National Health Insurance (NHI) claims data, and to compare characteristics of potentially high-expenditure subjects identified through different models.</p> <p>Methods</p> <p>A random sample of NHI enrollees continuously enrolled in 2002 and 2003 (n = 164,562) was selected. Health status measures and total expenditures derived from 2002 NHI claims data were used to predict the possibility of becoming 2003 top users. Statistics-based indicators (C-statistics, sensitivity, & Predictive Positive Value) and characteristics of identified top groups by different models (expenditures and prevalence of manageable diseases) were presented.</p> <p>Results</p> <p>Both diagnosis-based and prior expenditures models performed much better than the demographic model. Diagnosis-based models were better in identifying top users with manageable diseases; prior expenditures models were better in statistics-based indicators and identifying people with higher average expenditures. Prior expenditures status could correctly identify more actual top users than diagnosis-based or demographic models. The proportions of actual top users that could be identified by diagnosis-based models alone were much lower than that identified by prior expenditures status.</p> <p>Conclusions</p> <p>Predicted top users identified by different models have different characteristics and there is little agreement between modes regarding which groups would be potentially top users; therefore, which model to use should depend on the purpose of predictive modeling. Prior expenditures are a more powerful tool than diagnosis-based risk adjusters in terms of correctly identifying more actual high expenditures users. There is still much room left for improvement of diagnosis-based models in predictive modeling.</p