Search arXivSearch

arXiv · 1909.12881

A Data-Adaptive Targeted Learning Approach of Evaluating Viscoelastic Assay Driven Trauma Treatment Protocols

Abstract

Estimating the impact of trauma treatment protocols is complicated by the high dimensional yet finite sample nature of trauma data collected from observational studies. Viscoelastic assays are highly predictive measures of hemostasis. However, the effectiveness of thromboelastography(TEG) based treatment protocols has not been statistically evaluated.To conduct robust and reliable estimation with sparse data, we built an estimation "machine" for estimating causal impacts of candidate variables using the collaborative targeted maximum loss-based estimation(CTMLE) framework.The computational efficiency is achieved by using the scalable version of CTMLE such that the covariates are pre-ordered by summary statistics of their importance before proceeding to the estimation steps.To extend the application of the estimator in practice, we used super learning in combination with CTMLE to flexibly choose the best convex combination of algorithms. By selecting the optimal covariates set in high dimension and reducing constraints in choosing pre-ordering algorithms, we are able to construct a robust and data-adaptive model to estimate the parameter of interest.Under this estimation framework, CTMLE outperformed the other doubly robust estimators(IPW,AIPW,stabilized IPW,TMLE) in the simulation study. CTMLE demonstrated very accurate estimation of the target parameter (ATE). Applying CTMLE on the real trauma data, the treatment protocol (using TEG values immediately after injury) showed significant improvement in trauma patient hemostasis status (control of bleeding), and a decrease in mortality rate at 6h compared to standard care.The estimation results did not show significant change in mortality rate at 24h after arrival.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Linqing Wei, Lucy Z. Kornblith, Alan Hubbard. 2022-09-24. A Data-Adaptive Targeted Learning Approach of Evaluating Viscoelastic Assay Driven Trauma Treatment Protocols. https://arxiv.org/abs/1909.12881

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Relegation, promotion and the components of scoring in water polo

Relegation, not the championship, decides the outcome of many European water polo leagues: one club has won every recent national title in Italy, Spain and Hungary. We make the relegation decision our object of inference. Serie A1 relegates one club for finishing last and a second through a three-match play-out, and we ask at each stage how much can be known and when. Promoted clubs arrive with no top-flight record, so we also compare four ways of setting their prior. These analyses rest on the first Bayesian hierarchical model of water polo, which splits scoring into even-strength, man-up and penalty components, models opportunities and conversions separately, and lets abilities evolve between seasons. Treating the components as independent proves untenable, since they compete for a common budget of possessions. Fitted to a new dataset of 940 matches, the model identifies the directly relegated club from the ninth round, before the league table does, predicts the play-out field better than the table, and shows the play-out itself to be close to a coin toss. Promoted clubs start below the league on every component except drawing exclusions: knowing a club was promoted improves forecasts; knowing how does not.

stat.AP

Geospatial Foundation Models Capture Health-Relevant Dimensions of Place Beyond Conventional Social Risk Indices

Area-based social risk indices summarize residents' socioeconomic conditions but incompletely capture physical features of place that may affect health. We evaluated whether numerical representations of physical place produced by four geospatial foundation model families from 2022 satellite data explained residual variance in tract-level associations between the Area Deprivation Index, Social Deprivation Index, and Social Vulnerability Index with health outcomes. We used LightGBM to predict variables from the American Community Survey and 40 chronic disease and health-behavior outcomes from CDC PLACES across 82,646 census tracts in the contiguous United States, evaluating performance across 10 held-out states. Among survey variables, models were moderately predictive of some variables including housing type (R-squared up to 0.54) but weak for disability, unemployment, and income disparity. For health outcomes, models explained up to 54% of variance left unexplained by social risk indices, with the largest gains for annual checkups, arthritis, and high blood pressure. Mean total variance explained by geospatial foundation models across the 40 health-related outcomes increased from 0.31 in the smallest tract-size decile to 0.39 in the largest. Geospatial foundation models capture health-relevant features of place not represented by conventional social risk indices and may usefully augment them in epidemiological analyses.

stat.AP

Transporting summary measures of relative effects from randomised trials to the treated patient population: an application to breast cancer endocrine therapy

Randomised trials often report relative treatment effects, such as risk ratios and hazard ratios, for trial populations. Clinical decision-making, however, often benefits from estimates of absolute treatment effects in the population eligible for treatment. Trial participants may not represent this target population well, and restrictions on access to individual participant trial data can further complicate absolute effect estimation. Routine care data are often representative of the target population but may be subject to uncontrolled confounding. We consider estimation of the average treatment effect on the treated (ATT), an absolute measure, by combining a representative sample of treated routine care patients with summary measures (i.e., estimated risk or hazard ratios) from either a randomised trial or a meta-analysis of trials. Under marginal or conditional transportability assumptions, the ATT is shown to be identifiable. The implications of collapsibility of the effect measure on transportability are discussed, and plug-in estimators of the ATT are presented. Simulation studies are used to assess finite sample performance of the estimators in a range of settings. The proposed methods are applied to estimate the ATT of endocrine therapy on 15-year breast cancer mortality using results from a meta-analysis of randomised trials and England's National Disease Registration Service.

stat.AP