For more information, visit:

http://www.andywillan.com »»

Research Interests

• Biostatistics
• Clinical trial methodology
• Health economics
• Diagnostic tests

Research Activities

1. Development of biostatistical methods in clinical trial methodology, health economics and cost-effectiveness analysis.
2. Clinical trials in Paediatrics and Obstetrics.

Publications

Pullenayegum EM, Willan AR. Marginal models for censored longitudinal cost data: appropriate working variance matrices in inverse-probability-weighted GEEs can improve precision. International Journal of Biostatistics 2011; 7(1); www.bepress.com/ijb/vol7/iss1/14.

Eckermann S, Willan AR. Presenting and summarizing cost and effect evidence to best inform inference and societal decision making when comparing multiple strategies. PharmacoEconomics 2011; 29(7):563-577.

Eckermann S, Coory M, Willan AR. Consistently estimating risk difference when translating evidence to jurisdiction of interest. PharmacoEconomics 2011; 29(2):1-10.

Willan AR, Eckermann S. Optimal clinical trial design using value of information methods with imperfect implementation. Health Economics 2010; 19:549-561.

Eckermann S, Coory M, Willan AR. Indirect comparison: relative risk fallacies and odds solution. Journal of Clinical Epidemiology 2009; 62:1031-1036.

Eckermann S, Willan AR. Globally optimal trial design for local decision making. Health Economics 2009; 18:203-216.

Hossain A, Beyene J, Willan AR, Hu P. Approximate Likelihood ratio test for detecting differential expression in microarray data. Computational Statistics and Data Analysis 2009; 53(10):3685-3695.

Hodnett ED, Stremler R, Willan AR, Weston JA, Lowe NK, Simpson KR, Fraser WD, Gafni A; SELAN (Structured Early Labour Assessment and Care by Nurses) Trial Group, et al. Effect on birth outcomes of a formalised approach to care in hospital labour assessment units: international, randomised controlled trial. BMJ 2008; 337:a1021.

Murphy KE, Hannah ME, Willan AR et al. Multiple courses of antenatal corticosteroids for preterm birth study (MACS): a randomised controlled trial. Lancet 2008; 372:2143-2151

Willan AR. Optimal sample size determinations from an industry perspective based on the expected value of information. Clinical Trials 2008; 5:587-594.

Eckermann S, Willan AR. The option value of delay in health technology assessment. Medical Decision Making, 2008; 28:300-305.

Eckermann S, Briggs A, Willan AR. Health technology assessment in the cost-disutility plane. Medical Decision Making 2008; 28:172-181.

Eckermann S, Willan AR. Time and EVSI wait for no patient. Value in Health 2008; 11:522-526.

Willan AR, Kowgier ME. Determining optimal sample sizes for multi-stage randomized clinical trials using value of information methods. Clinical Trials 2008; 5:289-300.

Willan AR, Kowgier ME. Cost-effectiveness analysis of a multinational RCT with a binary measure of effectiveness and an interacting covariate. Health Economics 2008; 17:777-791.

Willan AR. Clinical decision making and the expected value of information. Clinical Trials 2007; 4:279-285.

Hossain A, Willan AR. Approximate MLEs of the parameters of location-scale models under type II censoring. Statistics 2007; 41(5): 385-394.

Pullenayegum EM, Willan AR. Semi-parametric regression models for cost-effectiveness analysis: improving the efficiency of estimation from censored data. Statistics in Medicine 2007; 26:3274-3299.

Eckermann S, Willan AR. Expected value of information and decision making in HTA. Health Economics. 2007; 16:195-209.

Manca A, Willan AR. Lost in translation: accounting for between country differences in the analysis of multinational cost effectiveness data. Pharmacoeconomics 2006; 24:1101-1119.

Willan AR, Briggs AH. The statistical analysis of cost-effectiveness data. Chichester UK: Wiley, 2006.

Willan AR. Statistical analysis of cost-effectiveness data from randomized clinical trials. Expert Rev. Phamacoeconomics Outcomes Res. 2006; 6:337-346.

Willan AR, Goeree, R, Pinto EM, McBurney C, Blackhouse G. Economic evaluation of rivastigmine in patients with Parkinson’s disease dementia. Pharmacoeconomics. 2006; 24:93-106.

Pinto EM, Willan AR and O’Brien BJ. Cost-effectiveness analysis for multinational clinical trials Statistics in Medicine. 2006; 24:1965-82.

Willan AR, Pinto EM. The expected value of information and optimal clinical trial design. Statistics in Medicine; 2005; 24:1791-1806.

Willan AR, Pinto EM, O’Brien BJ, Kaul P, Goeree R, Lynd L, Armstrong PW. Country specific cost comparisons from multinational clinical trials using empirical Bayesian shrinkage estimation: the Canadian ASSENT-3 economic analysis. Health Economics; 2005; 14: 327-338.

Willan AR, Lin DY, Manca A. Regression methods for cost-effectiveness analysis with censored data. Statistics in Medicine; 2005; 24:131-145.

Willan AR. Incremental net benefit in the analysis of economic data from clinical trials with application to the CADET-Hp Trial. European Journal of Gastroenterology and Hepatology; 2004; 16:543-549.

Willan AR, Briggs AH, Hoch JS. Regression methods for covariate adjustment and subgroup analysis for non-censored cost-effectiveness data. Health Economics; 2004; 13: 461-475.

Sears MR, Greene JM, Willan AR, Wiecek, EM, Taylor DR, Flannery EM, Cowan JO, Herbison GP, Silva PA, Poulton R. Persistence, remission and relapse of childhood asthma followed to adulthood: a longitudinal population-based cohort study. NEJM; 2003; 349(15): 1414-1422.

Willan AR, Chen E, Cook RJ, Lin DY. Incremental net benefit in randomized clinical trials with qualify-adjusted survival. Statistics in Medicine; 2003; 22:353-362.

Willan AR, Lin DY, Cook RJ, Chen E. Using inverse-weighing in cost-effectiveness analysis with censored data. Statistical Methods in Medical Research; 2002; 11:539-552.

Sears MR, Greene JM, Willan AR, Taylor DR, Flannery EM, Herbison GP, Poulton R. The long-term relationship between breast-feeding and development of atopy and asthma in children and young adults: a longitudinal study. The Lancet, 2002; 360;901-907.

O'Brien BJ, Gertsen K, Willan AR, Faulkner L. Is there a kink in consumers' threshold value for cost-effectiveness in health care. Health Economics. 2002; 11:175-180.

Willan AR, Lin DY. Incremental net benefit in randomized clinical trials. Stat Med. 2001; 20:1563-1574.

Willan AR. Analysis, sample size and power for estimating incremental net health benefit from clinical trial data. Control Clin Trials. 2001; 22:228-237.

Willan AR, O'Brien BJ, Leyva RA. Cost-effectiveness analysis when the WTA is greater than the WTP. Stat Med, 2001; 20:3251-3259.

Hoch JS, Briggs AH, Willan AR. Something old, something new, something borrowed, something blue: a framework for the marriage of health econometrics and cost-effectiveness analysis. Health Economics, 2001; 11:415-430.

Willan AR, O'Brien BJ. Cost prediction models for the comparison of two groups. Health Econ Let, 2001; 5:20-25.<</p>

Willan AR. On the probability of cost-effectiveness using data from randomized clinical trials. BMC Med Res Meth, 2001; 1:8. ( www.biomedcentral.com/1471-2288/1/8/ )

Hannah ME, Hannah, WJ, Hewson SA, Hodnett ED, Saigal S, Willan AR. Term Breech Trial: a multicentre international randomised controlled trial of planned caesarean section and planned vaginal birth for breech presentation at term. The Lancet, 2000; 356:1375-1383.

Willan AR, O'Brien BJ. Sample size and power issues in estimating incremental cost-effectiveness ratios from clinical trials data. Health Economics 1999; 8:203-211.