Wei‐Yann Tsai

Columbia University

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Dawn L. Hershman

Columbia University Irving Medical Center

Regina M. Santella

Columbia University

Alfred I. Neugut

Columbia University

Lawrence H. Kushi

Kaiser Permanente

Frederica P. Perera

Columbia University

Louise Kuhn

Columbia University

Judith S. Jacobson

Columbia University

Qiao Wang

Beijing Children’s Hospital

Hwai‐I Yang

National Yang Ming Chiao Tung University

Habibul Ahsan

University of Chicago

Cooperative Institutions

Columbia University

Columbia University Irving Medical Center

Center for Children

Icahn School of Medicine at Mount Sinai

NewYork–Presbyterian Hospital

National Cheng Kung University

University of the Witwatersrand

Harvard University

Herbert Irving Comprehensive Cancer Center

Royal College of Physicians

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Relation between prenatal lipid-soluble micronutrient status, environmental pollutant exposure, and birth outcomes

American Journal of Clinical Nutrition (2007)

Elizabeth T. Masters Wiesław Jędrychowski Rosemary L. Schleicher Wei‐Yann Tsai Yi-Hsuan Tu

10.1093/ajcn/86.4.1139

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Citations (46)

Confidence intervals for the ratio of two median residual lifetimes with left‐truncated and right‐censored data

Biometrics (2015)

Tsung‐Hsien Tsai Wei‐Yann Tsai Yunchan Chi Sheng‐Mao Chang

Summary The confidence intervals for the ratio of two median residual lifetimes are developed for left-truncated and right-censored data. The approach of Su and Wei (1993) is first extended by replacing the Kaplan–Meier survival estimator with the estimator of the conditional survival function (Lynden-Bell, 1971). This procedure does not involve a nonparametric estimation of the probability density function of the failure time. However, the Su and Wei type confidence intervals are very conservative even for larger sample size. Therefore, this article proposes an alternative confidence interval for the ratio of two median residual lifetimes, which is not only without nonparametric estimation of the density function of failure times but is also computationally simpler than the Su and Wei type confidence interval. A simulation study is conducted to examine the accuracy of these confidence intervals and the implementation of these confidence intervals to two real data sets is illustrated.

Robust confidence intervals

Coverage probability

Confidence distribution

Survival function

Tolerance interval

10.1111/biom.12378

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Citations (1)

Testing the equality of two survival functions with right truncated data

Statistics in Medicine (2006)

Yunchan Chi Wei‐Yann Tsai C.M. Chiang

Abstract To compare the survival functions based on right‐truncated data, Lagakos et al. proposed a weighted logrank test based on a reverse time scale. This is in contrast to Bilker and Wang, who suggested a semi‐parametric version of the Mann–Whitney test by assuming that the distribution of truncation times is known or can be estimated parametrically. The approach of Lagakos et al. is simple and elegant, but the weight function in their method depends on the underlying cumulative hazard functions even under proportional hazards models. On the other hand, a semi‐parametric test may have better efficiency, but it may be sensitive to misspecification of the distribution of truncation times. Therefore, this paper proposes a non‐parametric test statistic based on the integrated weighted difference between two estimated survival functions in forward time. The comparative results from a simulation study are presented and the implementation of these methods to a real data set is demonstrated. Copyright © 2006 John Wiley & Sons, Ltd.

Truncation (statistics)

Statistic

Log-rank test

Rank (graph theory)

Data set

Parametric model

10.1002/sim.2556

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Citations (17)

A note on the product-limit estimator under right censoring and left truncation

Biometrika (1987)

Wei‐Yann Tsai Nicholas P. Jewell Mei‐Cheng Wang

Journal Article A note on the product-limit estimator under right censoring and left truncation Get access WEI-YANN TSAI, WEI-YANN TSAI Applied Mathematics Department, Brookhaven National LaboratoryUpton, New York 11973, U.S.A. Search for other works by this author on: Oxford Academic Google Scholar NICHOLAS P. JEWELL, NICHOLAS P. JEWELL Program in Biostatistics & Department of Statistics, University of CaliforniaBerkeley, California 94720, U.S.A. Search for other works by this author on: Oxford Academic Google Scholar MEI-CHENG WANG MEI-CHENG WANG Department of Biostatistics, Johns Hopkins UniversityBaltimore, Maryland 21205, U.S.A. Search for other works by this author on: Oxford Academic Google Scholar Biometrika, Volume 74, Issue 4, December 1987, Pages 883–886, https://doi.org/10.1093/biomet/74.4.883 Published: 01 December 1987 Article history Received: 01 July 1985 Revision received: 01 February 1987 Published: 01 December 1987

Censoring (clinical trials)

Truncation (statistics)

Kaplan–Meier estimator

10.1093/biomet/74.4.883

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Citations (333)

A Note on the Censoring Problem in Empirical Case‐Outcome Studies

Journal of Empirical Legal Studies (2006)

Michael O. Finkelstein Bruce Levin Ian W. McKeague Wei‐Yann Tsai

In outcome studies of cases filed within a study window, the sample may be skewed if many cases are still pending when the window closes and not included in the study. We refer to cases that are completed within the window as “observed” and those still pending as “censored.” We propose two methods for reducing possible bias: a “self‐consistent” estimator that imputes values to the censored cases and an “inverse probability weighting” estimator that assigns weights to the observed cases. In the body of the article we describe these methods for the nonmathematical reader and in the Appendix give a more mathematical treatment. We then apply the self‐consistent estimator first to simulated data and then to the landmark study of reversals in death penalty cases by Professor James S. Liebman and his colleagues. In these examples the two methods are equivalent. Liebman et al. simply excluded censored cases and reported a reversal rate of 68%. Application of our methods to the Liebman data reduces the reversal rate to 62.2% (95% c.i. 60.1%, 64.4%). In general, our method largely removes the bias that affects sample estimates when censored cases are just ignored.

Censoring (clinical trials)

Inverse probability weighting

Inverse probability

Sample (material)

10.1111/j.1740-1461.2006.00073.x

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Citations (9)

Psychosocial factors related to non-persistence with adjuvant endocrine therapy among women with breast cancer: the Breast Cancer Quality of Care Study (BQUAL)

Breast Cancer Research and Treatment (2016)

Dawn L. Hershman Lawrence H. Kushi Grace Clarke Hillyer Ellie J. Coromilas Donna Buono

Discontinuation

10.1007/s10549-016-3788-x

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Citations (60)

Effect of Prenatal Exposure to Airborne Polycyclic Aromatic Hydrocarbonson Neurodevelopment in the First 3 Years of Life among Inner-City Children

Environmental Health Perspectives (2006)

Frederica P. Perera Virginia Rauh Robin M. Whyatt Wei‐Yann Tsai Deliang Tang

Our prospective cohort study of nonsmoking African-American and Dominican mothers and children in New York City is evaluating the role of prenatal exposure to urban pollutants, including polycyclic aromatic hydrocarbons (PAHs) , environmental tobacco smoke (ETS) , and pesticides, in the pathogenesis of neurobehavioral disorders. We used the Bayley Scales of Infant Development to evaluate the effects on child mental and psychomotor development of prenatal exposure to airborne PAHs monitored during pregnancy by personal air sampling. Behavioral development was assessed by the Child Behavior Checklist. We adjusted for potential confounders including sociodemographic factors and prenatal exposure to ETS and chlorpyrifos. Prenatal exposure to PAHs was not associated with psychomotor development index or behavioral problems. However, high prenatal exposure to PAHs (upper quartile) was associated with lower mental development index at age 3 [beta=-5.69; 95% confidence interval (CI), -9.05 to -2.33; p<0.01]. The odds of cognitive developmental delay were also significantly greater for children with high prenatal exposure (odds ratio=2.89; 95% CI, 1.33 to 6.25; p=0.01). General estimated equation analysis showed a significant age times PAH effect on mental development (p=0.01), confirming the age-specific regression findings. Further adjustment for lead did not alter the relationships. There were no differences in effect sizes by ethnicity. The results require confirmation but suggest that environmental PAHs at levels recently encountered in New York City air may adversely affect children's cognitive development at 3 years of age, with implications for school performance.

Child Behavior Checklist

Tobacco smoke

10.1289/ehp.9084

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Citations (452)

A prospective cohort study of early discontinuation of adjuvant chemotherapy in women with breast cancer: the breast cancer quality of care study (BQUAL)

Breast Cancer Research and Treatment (2016)

Alfred I. Neugut Grace Clarke Hillyer Lawrence H. Kushi Lois Lamerato Donna Buono

Discontinuation

Regimen

Chemotherapy regimen

10.1007/s10549-016-3855-3

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Citations (19)

Pimozide Augmentation of Clozapine Inpatients with Schizophrenia and Schizoaffective Disorder Unresponsive to Clozapine Monotherapy

Neuropsychopharmacology (2011)

Joseph I. Friedman Jean-Pierre Lindenmayer Frances Alcantara Stephanie Bowler Mohan Parak

Pimozide

10.1038/npp.2011.14

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Citations (35)

Aflatoxin B1 Exposure, Hepatitis B Virus Infection, and Hepatocellular Carcinoma in Taiwan

Cancer Epidemiology Biomarkers & Prevention (2009)

Hui-Chen Wu Qiao Wang Hwai‐I Yang Habibul Ahsan Wei‐Yann Tsai

Abstract To evaluate the role of aflatoxin B1 (AFB1) exposure on risk of hepatocellular carcinoma (HCC), a case-control study nested within a community-based cohort was conducted. Baseline blood and urine samples were used to determine the level of AFB1-albumin adducts and urinary AFB1 metabolites. Conditional logistic regression analysis was used to calculate odds ratios (OR) and 95% confidence intervals (95% CI) to assess the effect of AFB1 exposure on risk of HCC. The adjusted ORs (95% CIs) were 1.54 (1.01-2.36) and 1.76 (1.18-2.58), respectively, for those with AFB1-albumin adducts and urinary AFB1 metabolite levels above the mean compared with those with levels below the mean. When compared with subjects in the lowest quartile of urinary AFB1 metabolites, there was an increase in risk of HCC, with adjusted ORs (95% CIs) of 0.57 (0.14-2.43), 1.43 (0.32-6.42), and 4.91 (1.18-20.48; Ptrend = 0.02), respectively, among noncarriers of hepatitis B virus (HBV) infection. The adjusted OR (95% CI) was 7.49 (5.13-10.93) for carriers of hepatitis B surface antigen compared with noncarriers, regardless of AFB1 status. The ORs (95% CI) were 10.38 (5.73-18.82) and 15.13 (7.83-29.25) for carriers of hepatitis B surface antigens with levels of AFB1-albumin adducts and urinary AFB1 metabolites above the mean, respectively. The combined effect of aflatoxin exposure and HBV infection did not differ by duration of follow-up. Consistent with our previous study with fewer subjects, these data show that AFB1 exposure is a risk factor for HCC risk. However, in this larger study, the effect of combined AFB1 exposure and HBV infection is more consistent with an additive than a multiplicative model. (Cancer Epidemiol Biomarkers Prev 2009;18(3):846–53)

Hepatitis B

10.1158/1055-9965.epi-08-0697

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Citations (124)