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152. Immediate Breast Reconstruction for Inflammatory Breast Cancer: Trends in Use and Clinical Outcomes 2004–2016

Author

Hoffman, Daniel I., primary, Santos, Patricia Mae G., additional, Goldbach, Macy, additional, Keele, Luke J., additional, Taunk, Neil K., additional, Bogen, Hannah S., additional, Burkbauer, Laura, additional, Jankowitz, Rachel C., additional, Fosnot, Joshua, additional, Wu, Liza C., additional, Freedman, Gary M., additional, and Tchou, Julia C., additional

Published
2021
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158. Evaluation of Attention-Deficit/Hyperactivity Disorder Medications, Externalizing Symptoms, and Suicidality in Children

Author

Shoval, Gal, primary, Visoki, Elina, additional, Moore, Tyler M., additional, DiDomenico, Grace E., additional, Argabright, Stirling T., additional, Huffnagle, Nicholas J., additional, Alexander-Bloch, Aaron F., additional, Waller, Rebecca, additional, Keele, Luke, additional, Benton, Tami D., additional, Gur, Raquel E., additional, and Barzilay, Ran, additional

Published
2021
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167. Contrasting approaches for addressing non-adherence in randomized controlled trials: An illustration from the REFLUX trial.

Author

Keele, Luke and Grieve, Richard

Subjects
RANDOMIZED controlled trials, GASTROESOPHAGEAL reflux, MEDICAL protocols, MEDICATION therapy management, DESCRIPTIVE statistics, PATIENT compliance, STATISTICAL models, STATISTICAL sampling
Abstract

Background: In many randomized controlled trials, a substantial proportion of patients do not comply with the treatment protocol to which they have been randomly assigned. Randomized controlled trials are required to report results according to the intention-to-treat estimand, but recent methodological guidance recognizes the importance of estimating other causal quantities. Methods: This article outlines an analytical framework for randomized controlled trials with non-compliance. We apply the ICH E9 (R1) addendum and combine it with the potential outcomes framework to define key estimands, outline the major assumptions for identification of each estimand, and highlight the assumptions that cannot be verified from the randomized controlled trial data. We contrast the assumptions and estimates in a re-analysis of the REFLUX trial. We report alternative estimates for the effectiveness of receipt of laparoscopic surgery versus medical management for patients with gastro-intestinal reflux disease. Results: The article finds that adjusted as-treated and per-protocol estimates were similar in magnitude to those based intention-to-treat methods. Instrumental variable estimates of the complier average causal effect were larger, with wider confidence intervals. Conclusion: We recommend that in randomized controlled trials with non-compliance, studies should outline which estimand is most relevant to the study context, evaluate key assumptions, and present estimates from a range of methods as a sensitivity analysis. [ABSTRACT FROM AUTHOR]

Published
2022
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174. Refining the indications for neoadjuvant chemotherapy for patients with HER2+ breast cancer: A single institution experience

Author

Pomponio, Maria K., primary, Burkbauer, Laura, additional, Goldbach, Macy, additional, Nazarian, Susanna M., additional, Xie, Fei, additional, Clark, Amy S., additional, Matro, Jennifer M., additional, Fox, Kevin R., additional, Shulman, Lawrence N., additional, Keele, Luke J., additional, and Tchou, Julia, additional

Published
2020
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175. The Third Way

Author

Mackuen, Michael, primary, Marcus, George E., additional, Neuman, W. Russell, additional, and Keele, Luke, additional

Published
2007
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180. Risk Factors for Mortality in Pediatric Postsurgical versus Medical Severe Sepsis

Author

Thakkar, Rajan K., primary, Weiss, Scott L., additional, Fitzgerald, Julie C., additional, Keele, Luke, additional, Thomas, Neal J., additional, Nadkarni, Vinay M., additional, Muszynski, Jennifer A., additional, Hall, Mark W., additional, Fontela, P., additional, Tucci, M., additional, Dumistrascu, M., additional, Skippen, P., additional, Krahn, G., additional, Bezares, E., additional, Puig, G., additional, Puig-Ramos, A., additional, Garcia, R., additional, Villar, M., additional, Bigham, M., additional, Polanski, T., additional, Latifi, S., additional, Giebner, D., additional, Anthony, H., additional, Hume, J., additional, Galster, A., additional, Linnerud, L., additional, Sanders, R., additional, Hefley, G., additional, Madden, K., additional, Thompson, A., additional, Shein, S., additional, Gertz, S., additional, Han, Y., additional, Williams, T., additional, Hughes-Schalk, A., additional, Chandler, H., additional, Orioles, A., additional, Zielinski, E., additional, Doucette, A., additional, Zebuhr, C., additional, Wilson, T., additional, Dimitriades, C., additional, Ascani, J., additional, Layburn, S., additional, Valley, S., additional, Markowitz, B., additional, Terry, J., additional, Morzov, R., additional, Mcinnes, A., additional, McArthur, J., additional, Woods, K., additional, Murkowski, K., additional, Spaeder, M., additional, Sharron, M., additional, Wheeler, D., additional, Beckman, E., additional, Frank, E., additional, Howard, K., additional, Carroll, C., additional, Nett, S., additional, Jarvis, D., additional, Patel, V., additional, Higgerson, R., additional, Christie, L., additional, Typpo, K., additional, Deschenes, J., additional, Kirby, A., additional, Uhl, T., additional, Rehder, K., additional, Cheifetz, I., additional, Wrenn, S., additional, Kypuros, K., additional, Ackerman, K., additional, Maffei, F., additional, Bloomquist, G., additional, Rizkalla, N., additional, Kimura, D., additional, Shah, S., additional, Tigges, C., additional, Su, F., additional, Barlow, C., additional, Michelson, K., additional, Wolfe, K., additional, Goodman, D., additional, Campbell, L., additional, Sorce, L., additional, Bysani, K., additional, Monjure, T., additional, Evans, M., additional, Totapally, B., additional, Chegondi, M., additional, Rodriguez, C., additional, Frazier, J., additional, Steele, L., additional, Viteri, S., additional, Costarino, A., additional, Thomas, N., additional, Spear, D., additional, Hirshberg, E., additional, Lilley, J., additional, Rowan, C., additional, Rider, C., additional, Kane, J., additional, Zimmerman, J., additional, Greeley, C., additional, Lin, J., additional, Jacobs, R., additional, Parker, M., additional, Culver, K., additional, Loftis, L., additional, Jaimon, N., additional, Goldsworthy, M., additional, Fitzgerald, J., additional, Weiss, S., additional, Nadkarni, V., additional, Bush, J., additional, Diliberto, M., additional, Allen, C., additional, Gessouroun, M., additional, Sapru, A., additional, Lang, T., additional, Alkhouli, M., additional, Kamath, S., additional, Friel, D., additional, Daufeldt, J., additional, Hsing, D., additional, Carlo, C., additional, Pon, S., additional, Scimeme, J., additional, Shaheen, A., additional, Hassinger, A., additional, Qiao, H., additional, Giuliano, J., additional, Tala, J., additional, Vinciguerra, D., additional, Fernandez, A., additional, Carrero, R., additional, Hoyos, P., additional, Jaramillo, J., additional, Posada, A., additional, Izquiierdo, L., additional, Olave, B.E. Piñeres, additional, Donado, J., additional, Dalmazzo, R., additional, Rendich, S., additional, Palma, L., additional, Lapadula, M., additional, Acuna, C., additional, Cruces, P., additional, De Clety, S. Clement, additional, Dujardin, M., additional, Berghe, C., additional, Renard, S., additional, Zurek, J., additional, Steinherr, H., additional, Mougkou, K., additional, Critselis, E., additional, Di Nardo, M., additional, Picardo, S., additional, Tortora, F., additional, Rossetti, E., additional, Fragasso, T., additional, Cogo, P., additional, Netto, R., additional, Dagys, A., additional, Gurskis, V., additional, Kevalas, R., additional, Neeleman, C., additional, Lemson, J., additional, Luijten, C., additional, Wojciech, K., additional, Pagowska-Klimek, I., additional, Szczepanska, M., additional, Karpe, J., additional, Nunes, P., additional, Almeida, H., additional, Rios, J., additional, Vieira, M., additional, Iniguez, J. P. Garcia, additional, Revilla, P., additional, Urbano, J., additional, Lopez-Herce, J., additional, Bustinza, A., additional, Palacios, A., additional, Hofheinz, S., additional, Rodriguez-Nunez, A., additional, Sanagustin, S., additional, Gonzalez, E., additional, Riaza, M., additional, Piaya, R., additional, Soler, P., additional, Esteban, E., additional, Laraudogoitia, J., additional, Monge, C., additional, Herrera, V., additional, Granados, J., additional, Gonzalez, C., additional, Koroglu, T., additional, Ozcelik, E., additional, Baines, P., additional, Plunkett, A., additional, Davis, P., additional, George, S., additional, Tibby, S., additional, Harris, J., additional, Agbeko, R., additional, Lampitt, R., additional, Brierley, J., additional, Peters, M., additional, Jones, A., additional, Dominguez, T., additional, Thiruchelvam, T., additional, Deep, A., additional, Ridley, L., additional, Bowen, W., additional, Levin, R., additional, Macleod, I., additional, Gray, M., additional, Hemat, N., additional, Alexander, J., additional, Ali, S., additional, Pappachan, J., additional, McCorkell, J., additional, Fortune, P., additional, MacDonald, M., additional, Hudnott, P., additional, Suyun, Q., additional, Singhi, S., additional, Nallasamy, K., additional, Lodha, R., additional, Shime, N., additional, Tabata, Y., additional, Saito, O., additional, Ikeyama, T., additional, Kawasaki, T., additional, Lum, L., additional, Abidin, A., additional, Kee, S., additional, Tang, S., additional, Jalil, R., additional, Guan, Y., additional, Yao, L., additional, Lin, K., additional, Ong, J., additional, Salloo, A., additional, Doedens, L., additional, Mathivha, L., additional, Reubenson, G., additional, Moaisi, S., additional, Pentz, A., additional, Green, R., additional, Schibler, A., additional, Erickson, S., additional, McEneiry, J., additional, Long, D., additional, Dorofaeff, T., additional, Coulthard, M., additional, Millar, J., additional, Delzoppo, C., additional, Williams, G., additional, Morritt, M., additional, Watts, N., additional, Beca, J., additional, Sherring, C., additional, and Bushell, T., additional

Published
2019
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182. Extrapolating Treatment Effects in Multi-Cutoff Regression Discontinuity Designs.

Author

Cattaneo, Matias D., Keele, Luke, Titiunik, Rocío, and Vazquez-Bare, Gonzalo

Subjects
*REGRESSION discontinuity design, *TREATMENT effectiveness, *EXTRAPOLATION, *CAUSAL inference
Abstract

Abstract–In nonexperimental settings, the regression discontinuity (RD) design is one of the most credible identification strategies for program evaluation and causal inference. However, RD treatment effect estimands are necessarily local, making statistical methods for the extrapolation of these effects a key area for development. We introduce a new method for extrapolation of RD effects that relies on the presence of multiple cutoffs, and is therefore design-based. Our approach employs an easy-to-interpret identifying assumption that mimics the idea of "common trends" in difference-in-differences designs. We illustrate our methods with data on a subsidized loan program on post-education attendance in Colombia, and offer new evidence on program effects for students with test scores away from the cutoff that determined program eligibility. for this article are available online. [ABSTRACT FROM AUTHOR]

Published
2021
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183. Analysis of Benefit of Intensive Care Unit Transfer for Deteriorating Ward Patients: A Patient-Centered Approach to Clinical Evaluation

Author

Grieve, Richard, O'Neill, Stephen, Basu, Anirban, Keele, Luke, Rowan, Kathryn M, and Harris, Steve

Abstract

Importance: It is unknown which deteriorating ward patients benefit from intensive care unit (ICU) transfer. Objectives: To use an instrumental variable (IV) method that assesses heterogeneity and to evaluate estimates of person-centered treatment effects of ICU transfer and 28-day hospital mortality by age and illness severity. Design, Setting, and Participants: An analysis of a prospective cohort study from November 1, 2010, to December 31, 2011. The dates of this analysis were June 1, 2017, to June 30, 2018. The setting was a multicenter study of 49 UK National Health Service hospitals. Participants were 9192 deteriorating ward patients assessed for ICU transfer (4596 matched pairs). The study matched on baseline characteristics to strengthen the IV and to balance observed confounders between the comparison groups. Exposures: Transfer to the ICU or continued care on general wards. Main Outcomes and Measures: Mortality at 28 days (primary outcome) and 90 days. To address unobserved confounding, ICU bed availability was the IV for whether or not a patient was transferred. The study used the IV approach to evaluate estimates of treatment effect of ICU transfer and mortality according to age and physiological severity alone and in combination. Results: Both comparison groups included 4596 patients. In the group assessed with "many" ICU beds available (median, 7), 52.8% were male, and the mean (SD) age was 65.2 (17.7) years; in the group assessed with "few" ICU beds available (median, 2), 53.3% were male, and the mean (SD) age was 65.0 (17.3) years. The overall 28-day mortality estimates were 23.2% (2090 predicted deaths) if all of the matched patients were transferred vs 28.1% (2534 predicted deaths) if none of the matched patients were transferred, an estimated risk difference of -4.9% (95% CI, -26.4% to 16.6%). The estimated effects of ICU transfer differed by age and by physiological severity according to the National Early Warning Score (NEWS): the absolute risk differences in 28-day mortality after ICU transfer ranged from 7.7% (95% CI, -5.5% to 21.0%) for ages 18 to 23 years to -5.0% (95% CI -26.5% to 16.6%) for age 78 to 83 years and ranged from 3.7% (95% CI, -12.1% to 19.5%) for NEWS of 0 to -25.4% (95% CI, -50.6% to -0.2%) for NEWS of 19. The absolute risk differences for elderly patients (≥75 years) were -11.6% (95% CI, -39.0% to 15.8%) for those with high NEWS (>6), -4.8% (95% CI, -30.5% to 20.9%) for those with moderate NEWS (5-6), and -1.0% (95% CI, -24.8% to 22.8%) for those with low NEWS (

Published
2019

184. Causal interaction and effect modification: same model, different concepts.

Author

Keele, Luke and Stevenson, Randolph T.

Subjects
CAUSAL inference, POLITICAL science
Abstract

Social scientists use the concept of interactions to study effect dependency. In the causal inference literature, interaction terms may be used in two distinct type of analysis. The first type of analysis focuses on causal interactions, where the analyst is interested in whether two treatments have differing effects when both are administered. The second type of analysis focuses on effect modification, where the analyst investigates whether the effect of a single treatment varies across levels of a baseline covariate. While both forms of interaction analysis are typically conducted using the same type of statistical model, the identification assumptions for these two types of analysis are very different. In this paper, we clarify the difference between these two types of interaction analysis. We demonstrate that this distinction is mostly ignored in the political science literature. We conclude with a review of several applications where we show that the form of the interaction is critical to proper interpretation of empirical results. [ABSTRACT FROM AUTHOR]

Published
2021
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186. Spillover Effects in Cluster Randomized Trials with Noncompliance

Author

Kang, Hyunseung and Keele, Luke

Subjects
Methodology (stat.ME), FOS: Computer and information sciences, Statistics - Methodology
Abstract

Cluster randomized trials (CRTs) are popular in public health and in the social sciences to evaluate a new treatment or policy where the new policy is randomly allocated to clusters of units rather than individual units. CRTs often feature both noncompliance, when individuals within a cluster are not exposed to the intervention, and individuals within a cluster may influence each other through treatment spillovers where those who comply with the new policy may affect the outcomes of those who do not. Here, we study the identification of causal effects in CRTs when both noncompliance and treatment spillovers are present. We prove that the standard analysis of CRT data with noncompliance using instrumental variables does not identify the usual complier average causal effect when treatment spillovers are present. We extend this result and show that no analysis of CRT data can unbiasedly estimate local network causal effects. Finally, we develop bounds for these causal effects under the assumption that the treatment is not harmful compared to the control. We demonstrate these results with an empirical study of a deworming intervention in Kenya.

Published
2018
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197. A contemporary analysis of palliative procedures in aborted pancreatoduodenectomy: Morbidity, mortality, and impact on future therapy.

Author

Azari, Feredun S., Vollmer, Charles M., Roses, Robert E., Keele, Luke, DeMatteo, Ronald P., Drebin, Jeffrey A., and Lee IV, Major Kenneth

Abstract

Periampullary malignancies are often unresectable tumors that frequently cause biliary or duodenal obstruction. Advances in endoscopic and percutaneous options have lessened the need for operative palliation. Nevertheless, many patients are still found to be unresectable at the time of exploration, making palliative bypass a consideration. Several prior studies have examined the morbidity of operative palliation, but many were conducted over lengthy time periods, and few have examined the impact of these procedures on future therapy. This study is a contemporary analysis of the short- and long-term outcomes of palliative bypass procedures for unresectable periampullary malignancies at a single high-volume institution. We identified a contemporary cohort of patients in whom a pancreatoduodenectomy was planned for periampullary malignancy but instead underwent an aborted procedure. Patients were divided into 5 procedure groups: laparoscopy only, laparotomy with or without cholecystectomy, gastrointestinal bypass, biliary bypass, and double bypass (gastrointestinal and biliary). Data regarding the patient cohort, procedures, morbidity/mortality, and the interval to initiation of systemic therapy were collected prospectively and reviewed retrospectively. Between July 2011 and November 2018, 128 out of 615 (17%) patients had an aborted pancreatoduodenectomy; 113 out of 128 patients had pancreatic adenocarcinoma, and 86 (67.1%) had duodenal or biliary obstruction at the time of operation. Patients who underwent laparoscopy only (n = 34) had no operative complications and a 90-day mortality of 6%; 88% of these patients went on to receive systemic therapy (median 21 days postprocedure). Double bypass was associated with a far lesser complication rate than in prior studies; 17% of patients had some complication(s), but only 9% had a severe complication. The 90-day all-cause mortality was 13%, and only 71% of these patients went on to receive systemic therapy (median 47 days postprocedure). Notably, 27 out of 34 (79%) of patients who underwent laparoscopy alone needed additional procedures for local obstruction, whereas only 5 out of 42 (12%) double bypass patients needed additional interventions. Median survival for the entire cohort was 10.3 months. Palliative procedures in this cohort had a far lesser complication rate than that of historical series. Palliative procedures, however, delayed systemic therapy, and a fair number of patients never received additional treatments. Palliative procedures markedly decreased the need for future interventions. Intraoperative decisions regarding palliative procedures must incorporate the functional status and motivations of the patient; these procedures are increasingly safe but may still affect survival. [ABSTRACT FROM AUTHOR]

Published
2020
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198. Stronger instruments and refined covariate balance in an observational study of the effectiveness of prompt admission to intensive care units.

Author

Keele, Luke, Harris, Steve, Pimentel, Samuel D., and Grieve, Richard

Subjects
INTENSIVE care units, SCIENTIFIC observation, ALGORITHMS
Abstract

Summary: Instrumental variable methods, subject to appropriate identification assumptions, enable consistent estimation of causal effects in the presence of unobserved confounding. Near–far matching has been proposed as one analytic method to improve inference by strengthening the effect of the instrument on the exposure and balancing observable characteristics between groups of subjects with low and high values of the instrument. However, in settings with hierarchical data (e.g. patients nested within hospitals), or where several covariate interactions must be balanced, conventional near–far matching algorithms may fail to achieve the requisite covariate balance. We develop a new matching algorithm, that combines near–far matching with refined covariate balance, to balance large numbers of nominal covariates while also strengthening the instrumental variable. This extension of near–far matching is motivated by a case‐study that aims to identify the causal effect of prompt admission to an intensive care unit on 7‐day and 28‐day mortality. [ABSTRACT FROM AUTHOR]

Published
2020
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200. Defining the Safety Profile for Performing Pancreatoduodenectomy in the Setting of Hyperbilirubinemia.

Author

Chen, Bofeng, Trudeau, Maxwell T., Maggino, Laura, Ecker, Brett L., Keele, Luke J., DeMatteo, Ronald P., Drebin, Jeffrey A., Fraker, Douglas L., Lee IV, Major K., Roses, Robert E., and Vollmer, Charles M.

Abstract

Background: Hyperbilirubinemia is commonly observed in patients requiring pancreatoduodenectomy (PD). Thus far, literature regarding the danger of operating in the setting of hyperbilirubinemia is equivocal. What remains undefined is at what specific level of bilirubin there is an adverse safety profile for undergoing PD. The aim of this study is to identify the optimal safety profile of patients with hyperbilirubinemia undergoing PD. Patients and Methods: The present work analyzed 803 PDs from 2004 to 2018. A generalized additive model was used to determine cutoff values of total serum bilirubin (TB) that were associated with increases in adverse outcomes, including 90-day mortality. Subgroup comparisons and biliary stent-specific analyses were performed for patients with TB below and above the cutoff. Results: TB of 13 mg/dL was associated with an increase in 90-day mortality (P = 0.043) and was the dominant risk factor on multivariate logistic regression [odds ratio (OR) 8.193, P = 0.001]. Increased TB levels were also associated with reoperations, number of complications per patient, and length of stay. Patients with TB greater than or equal to 13 mg/dL (TB ≥ 13) who received successful biliary decompression through stenting had less combined death and serious morbidity (P = 0.048). Conclusions: Preoperative TB ≥ 13 mg/dL was associated with increased 90-day mortality after PD. Reducing a TB ≥ 13 is generally recommended before proceeding to surgery. [ABSTRACT FROM AUTHOR]

Published
2020
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