Research Topics
| Haitao ChuSummaryAffiliation: Johns Hopkins Bloomberg School of Public Health Country: USA Publications
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Detail Information
Publications
Bayesian estimation of vaccine efficacyHaitao Chu
Department of Biostatistics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
Clin Trials 1:306-14. 2004..We illustrate the methods using the data from two pertussis vaccine studies and the H. influenza Type B preventive trial...- Estimating heterogeneous transmission with multiple infectives using MCMC methodsHaitao Chu
Department of Biostatistics, Rollins School of Public Health, Emory University, 1518 Clifton Road NE, Atlanta, GA 30322, USA
Stat Med 23:35-49. 2004..Parameters are estimated using Markov chain Monte Carlo methods... - Estimating vaccine efficacy using auxiliary outcome data and a small validation sampleHaitao Chu
Department of Biostatistics, Rollins School of Public Health, Emory University, 1518 Clifton Road NE, Atlanta, GA 30322, USA
Stat Med 23:2697-711. 2004..Comparing the performance of these approaches using data from a field study of influenza vaccine and simulations, we recommend to use the Bayesian method in this situation... - Assessing the effect of interventions in the context of mixture distributions with detection limitsHaitao Chu
Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe Street, Baltimore, MD 21205, U S A
Stat Med 24:2053-67. 2005..We illustrate our methods using data from a randomized clinical trial conducted in Qidong, People's Republic of China... - Individual variation in CD4 cell count trajectory among human immunodeficiency virus-infected men and women on long-term highly active antiretroviral therapy: an application using a Bayesian random change-point modelHaitao Chu
Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
Am J Epidemiol 162:787-97. 2005..At the individual level, 35% of men in the Multicenter AIDS Cohort Study versus 25% of women in the Women's Interagency HIV Study had a statistically significant change in CD4 cell count trajectory within 7 years after HAART initiation... - Estimating biomarker-based HIV incidence using prevalence data in high risk groups with missing outcomesHaitao Chu
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
Biom J 48:772-9. 2006..Our methods can be applied to estimate the incidence of other diseases from prevalence data using similar testing algorithms when missing data is present... - A note on comparing exposure data to a regulatory limit in the presence of unexposed and a limit of detectionHaitao Chu
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
Biom J 47:880-7. 2005..A simulation study is conducted to investigate the performance of the proposed sample size calculation methods... - Sample size and statistical power assessing the effect of interventions in the context of mixture distributions with detection limitsHaitao Chu
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
Stat Med 25:2647-57. 2006..A Monte Carlo simulation study is conducted to investigate the performance of the proposed methods... 
Bayesian posterior distributions without Markov chainsStephen R Cole
Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 27599 7435, USA
Am J Epidemiol 175:368-75. 2012..The transparency of the proposed approach comes at a price of being less broadly applicable than MCMC...- Longitudinal increases in waist circumference are associated with HIV-serostatus, independent of antiretroviral therapyTodd T Brown
Division of Endocrinology and Metabolism, Johns Hopkins University, 1830 East Monument Street, Baltimore, MD 21287, USA
AIDS 21:1731-8. 2007..The relative contributions of the different classes of antiretroviral therapy (ART), HIV infection per se, and aging to body shape changes in HIV-infected patients have not been clearly defined in longitudinal studies... - Confidence intervals for biomarker-based human immunodeficiency virus incidence estimates and differences using prevalent dataStephen R Cole
Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
Am J Epidemiol 165:94-100. 2007..The Monte Carlo-based CI may be preferable to competing methods because of the ease of extension to the incidence difference or to exploration of departures from assumptions... - Sample size and power determination in joint modeling of longitudinal and survival dataLiddy M Chen
Department of Biostatistics, University of North Carolina, Chapel Hill, NC 27599, U S A
Stat Med 30:2295-309. 2011..Optimal frequency of repeated measurements also depends on the nature of the trajectory with higher polynomial trajectories and larger measurement error requiring more frequent measurements... - A general approach for sample size and statistical power calculations assessing of interventions using a mixture model in the presence of detection limitsLei Nie
Department of Biostatistics, Bioinformatics, and Biomathematics, Georgetown University, 4000 Reservoir Road, Washington, DC 20057, USA
Contemp Clin Trials 27:483-91. 2006..The simulation results illustrate that the proposed methods provide adequate sample size estimates. However, when the aforementioned irregularity occurs, our methods are restricted and further research is needed... - Survival attributable to an exposureChristopher Cox
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
Stat Med 28:3276-93. 2009..We apply these methods to assess the effect of introducing highly active antiretroviral therapy for the treatment of clinical AIDS at the population level... - Bimodal virological response to antiretroviral therapy for HIV infection: an application using a mixture model with left censoringXiuhong Li
Room E7648, Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
J Epidemiol Community Health 60:811-8. 2006..This data analysis overcomes limitations of measurement techniques of observations having values below detection limits and serves to characterise the dynamics of the virological response to therapies... - Combined analysis of retrospective and prospective occurrences in cohort studies: HIV-1 serostatus and incident pneumoniaStephen R Cole
Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
Int J Epidemiol 35:1442-6. 2006..The authors show how information collected on retrospective occurrence times may be combined with prospective occurrence times in the analysis of recurrent events from cohort studies... 
Estimation of risk ratios in cohort studies with common outcomes: a Bayesian approachHaitao Chu
Department of Biostatistics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
Epidemiology 21:855-62. 2010..We propose a novel Bayesian approach for the estimation of the risk ratio from the log binomial model that addresses drawbacks of existing approaches. Posterior computation can be accomplished easily using the WinBUGs code provided...- Illustrating bias due to conditioning on a colliderStephen R Cole
Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, NC, USA
Int J Epidemiol 39:417-20. 2010..In both examples, conditioning on the common effect imparts an association between two otherwise independent variables; we call this selection bias... - On the estimation of disease prevalence by latent class models for screening studies using two screening tests with categorical disease status verified in test positives onlyHaitao Chu
Department of Biostatistics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
Stat Med 29:1206-18. 2010..In summary, further research is needed to reduce the impact of model misspecification on the estimation of disease prevalence in such settings... - Multiple-imputation for measurement-error correctionStephen R Cole
Department of Epidemiology, 615 Norht Wolfe Street, E7640, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
Int J Epidemiol 35:1074-81. 2006..There are many methods for measurement-error correction. These methods remain rarely used despite the ubiquity of measurement error... - Random effects regression models for trends in standardised mortality ratiosDavid B Richardson
Department of Epidemiology, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
Occup Environ Med 70:133-9. 2013..However, because the distribution of people with respect to age usually changes as calendar time advances, comparisons of SMRs across calendar periods can produce misleading results... - Basic concepts and methods for joint models of longitudinal and survival dataJoseph G Ibrahim
Department of Biostatistics, University of North Carolina, Chapel Hill, NC 27599, USA
J Clin Oncol 28:2796-801. 2010..To demonstrate our points throughout, we present an analysis from the Eastern Cooperative Oncology Group trial E1193, as well as examine some operating characteristics of joint models through simulation studies... - Meta-analysis of randomized trials on the association of prophylactic acyclovir and HIV-1 viral load in individuals coinfected with herpes simplex virus-2Christina Ludema
Department of Epidemiology, University of North Carolina, Chapel Hill, USA
AIDS 25:1265-9. 2011..To summarize the randomized evidence regarding the association between acyclovir use and HIV-1 replication as measured by plasma HIV-1 RNA viral load among individuals coinfected with herpes simplex virus (HSV)-2... - Longitudinal anthropometric changes in HIV-infected and HIV-uninfected menTodd Brown
Johns Hopkins University, Baltimore, MD 21287, USA
J Acquir Immune Defic Syndr 43:356-62. 2006.... - On estimation of vaccine efficacy using validation samples with selection biasDaniel O Scharfstein
Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
Biostatistics 7:615-29. 2006..Our approach is generally applicable to studies with missing binary outcomes with categorical covariates... - Parametric survival analysis and taxonomy of hazard functions for the generalized gamma distributionChristopher Cox
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA
Stat Med 26:4352-74. 2007..Description of standard statistical software (Stata, SAS and S-Plus) for the computations is included and available at http://statepi.jhsph.edu/software... - Sensitivity analysis of misclassification: a graphical and a Bayesian approachHaitao Chu
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
Ann Epidemiol 16:834-41. 2006..CONCLUSION: By using Bayesian methods, investigators can incorporate uncertainty about misclassification into probabilistic inferences... - Meta-analysis of diagnostic accuracy studies accounting for disease prevalence: alternative parameterizations and model selectionHaitao Chu
Department of Biostatistics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
Stat Med 28:2384-99. 2009..In summary, the proposed trivariate random effects models are novel and can be very useful in practice for meta-analysis of diagnostic accuracy studies... - Effect of acyclovir on herpetic ocular recurrence using a structural nested modelStephen R Cole
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street Room E7640, Baltimore, MD 21205, United States
Contemp Clin Trials 26:300-10. 2005..41 times that of the non-exposed (test-based 95% CI: 0.28, 0.72), or 34% larger than the intent-to-treat estimate. Notwithstanding excellent compliance, intent-to-treat estimates may notably undervalue the causal effect of a treatment... - Lagging exposure information in cumulative exposure-response analysesDavid B Richardson
Department of Epidemiology, School of Public Health, University of North Carolina at Chapel Hill, NC 27599, USA
Am J Epidemiol 174:1416-22. 2011..Lagging exposure assignment by a constant will lead to bias toward the null if the distribution of latency periods is not a fixed constant. Direct estimation of latency periods can minimize bias and improve confidence interval coverage... - An intervention to decrease catheter-related bloodstream infections in the ICUPeter Pronovost
School of Medicine, Johns Hopkins University, Baltimore, USA
N Engl J Med 355:2725-32. 2006..50) at 16 to 18 months. CONCLUSIONS: An evidence-based intervention resulted in a large and sustained reduction (up to 66%) in rates of catheter-related bloodstream infection that was maintained throughout the 18-month study period... - Bayesian methods in clinical trials: a Bayesian analysis of ECOG trials E1684 and E1690Joseph G Ibrahim
Department of Biostatistics, University of North Carolina, Chapel Hill, NC 27599, USA
BMC Med Res Methodol 12:183. 2012..The analyses of E1684 and E1690 were carried out separately when the results were published, and there were no further analyses trying to perform a single analysis of the combined trials... - Missing data in clinical studies: issues and methodsJoseph G Ibrahim
Department of Biostatistics, University of North Carolina, CB 7420, Chapel Hill, NC 27599, USA
J Clin Oncol 30:3297-303. 2012..Although the main area of application discussed here is cancer, the issues and methods we discuss apply to any type of study... - Estimating efficacy of trivalent, cold-adapted, influenza virus vaccine (CAIV-T) against influenza A (H1N1) and B using surveillance culturesM Elizabeth Halloran
Department of Biostatistics, Rollins School of Public Health, Emory University, 1518 Clifton Road NE, Atlanta, GA 30322, USA
Am J Epidemiol 158:305-11. 2003..CAIV-T provides substantial protection against a mixture of influenza A (H1N1) and B. Results demonstrate the powerful potential of using validation sets for outcomes in vaccine field studies... - A Bayesian approach estimating treatment effects on biomarkers containing zeros with detection limitsHaitao Chu
Department of Biostatistics and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
Stat Med 27:2497-508. 2008..Stat. Med. 2005; 24:2053-2067) through simulation studies and a randomized chemoprevention trial conducted in Qidong, People's Republic of China... - Re: "Confidence intervals for biomarker-based human immunodeficiency virus incidence estimates and differences using prevalent data"Stephen R Cole
Am J Epidemiol 166:861-2. 2007 - Prospective study of attitudinal and relationship predictors of sexual risk in the multicenter AIDS cohort studyDavid G Ostrow
David Ostrow and Associates, Chicago MACS Howard Brown Health Center and Northwestern University School of Medicine, 5455 N Sheridan Rd, Suite 1207, Chicago, IL 60640, USA
AIDS Behav 12:127-38. 2008..We conclude that HIV prevention efforts should target modifiable attitudes (reduced concern about HIV and safer sex fatigue) and increases in sexual risk-taking of MSM, particularly among HIV+ men having sex with serodiscordant partners... - Sample size calculation using exact methods in diagnostic test studiesHaitao Chu
J Clin Epidemiol 60:1201-2; author reply 1202. 2007 - Association of rear seat safety belt use with death in a traffic crash: a matched cohort studyMotao Zhu
Bureau of Injury Prevention, New York State Department of Health, Albany, New York 12204, USA
Inj Prev 13:183-5. 2007..To estimate the association of rear seat safety belt use with death in a traffic crash... - Bivariate meta-analysis of sensitivity and specificity with sparse data: a generalized linear mixed model approachHaitao Chu
J Clin Epidemiol 59:1331-2; author reply 1332-3. 2006