CLINICAL TRIALS CTR



Researcher : Ansari MT

List of Research Outputs

Ansari M.T., Cheung B.M.Y. and Karlberg J.P.E., Prolonged Seated Immobility-associated Venous Coagulability in a Factor V Leiden Heterozygote:a Case-comparative Study, Blood Coagulation and Fibrinolysis. 2006, 17: 187-191.


Researcher : Fong DYT

Project Title:Use of multiple imputation on linear mixed model and generalized estimating equations for longitudinal data analysis: a simulation study
Investigator(s):Fong DYT, Lam KSL
Department:Nursing Studies
Source(s) of Funding:Small Project Funding
Start Date:11/2005
Completion Date:10/2006
Abstract:
Purpose of the proposed project: 1. To assess the performance of the mixed effects model and generalized estimating equations with and without using multiple imputation in estimating treatment effects on a continuous outcome at different time epochs. 2. To determine whether multiple imputation adds advantage to the use of mixed effects model or generalized estimating equations. Key issues and problems: 1. Missing values are frequent in clinical trials when study subjects are measured longitudinally due to many reasons, including dropouts, non-compliance, and adverse events. Common methods of longitudinal data analysis that are consistent to the intention-to-treat principle are the mixed effects model (MEM) and the generalized estimating equation (GEE) (Goldstein et al., 2002; Chan et al., 2005; Edwards, 2000; Wagner et al., 2005; Dahmen & Ziegler, 2004). Alternatively, multiple imputation (MI) emerged as a method to facilitate the use of methods that do not accommodate missing values. There has recently been an interest in examining the use of imputation methods on MEM and GEE. Several studies examined the use of GEE with and without MI on real datasets. However, it is still unclear about the performance of using MI together with MEM or GEE in a clinical trial setting when the objective is to determine the treatment effect at specific time epochs. 2. According to Rubin (1976), missing value mechanism can be classified as missing completely at random (MCAR) when the probability of having a missing value does not depend on the observed values nor the missing values had they were observed, missing at random (MAR) when the probability depends on the observed values only, and missing not at random (MNAR) when the probability depends on the missing values had they were observed. There has been no report of simulation results on the performance of using MI on MEM and GEE when missing values are missing not at random. References: 1. Rubin D. Inference and Missing Data. Biometrika 1976; 63(3):581-590. 2. Goldstein H, Browne W, Rasbash J. Multilevel modelling of medical data. Statistics in Medicine 2002; 21(21):3291-3315. 3. Chan YM, Lee PWH, Fong DYT, Fung ASM, Wu LYF, Choi AYY, Ng TY, Wong LC, Ngan HYS. The effect of psychosocial intervention in women with gynecological malignancy: A randomized controlled trial and a staff-in-service training programme. To appear in Journal of Clinical Oncology 2005. 4. Edwards LJ. Modern statistical techniques for the analysis of longitudinal data in biomedical research. Pediatric Pulmonology 2000; 30(4):330-344. 5. Wagner AK, Fabio A, Puccio AM, Hirschberg R, Li W, Zafonte RD, Marion DW. Gender associations with cerebrospinal fluid glutamate and lactate/pyruvate levels after severe traumatic brain injury. Critical Care Medicine 2005; 33(2):407-413. 6. Dahmen G, Ziegler A. Generalized estimating equations in controlled clinical trials: Hypotheses testing. Biometrical Journal 2004; 46(2):214-232.


Project Title:Cost and clinical effectiveness of the Hong Kong scoliosis
Investigator(s):Fong DYT, Cheung KMC, Luk KDK, Cheng JCY, Ng BKW, Yip PSF
Department:Nursing Studies
Source(s) of Funding:Public Policy Research
Start Date:04/2006
Abstract:
To estimate the cost of the scoliosis screening programme in Hong Kong; to examine the clinical effectiveness of the screening programme in terms of its efficacy and referral rates; to study the epidemiology of scoliosis in Hong Kong; to examine if a more discriminative screening program can be performed on the at risk age group a more selective group of children; to study the outcome of screened cases, the cost of subsequent follow up and treatment.


List of Research Outputs

Chan Y.M., Lee P.W.H., Fong D.Y.T., Fung A.S.M., Wu L.Y.F., Choi A.Y., Ng T.Y., Ngan H.Y.S. and Wong L.C., Effect of individual psychological intervention in Chinese women with gynecologic malignancy: A randomized controlled trial, Journal of Clinical Oncology. 2005, 23(22): 4913-4924.
Ni G., Lu W.W., Chiu P.K.Y., Li Z., Fong D.Y.T. and Luk K.D.K., Strontium-containing hydroxyapatite (Sr-HA) bioactive cement for primary hip replacement: An in vivo study, J Biomed Mater Res Part B: Appl Biomater. 2006, 77B: 409-415.


Researcher : Huang J

Project Title:Hepatitis B or Hepatitis C viral infection and genotypes - which subgroup is more prone to the development of hepatocellular carcinoma? A systematic review
Investigator(s):Huang J, Wong BCY, Lai CL, Yuen RMF
Department:Clinical Trials Ctr
Source(s) of Funding:Health and Health Services Research Fund - Full Grants
Start Date:01/2004
Abstract:
To identify which subgroups of population infected with HBV/HCV are at higher risk for developing hepatocellular carcinoma (HCC).


Project Title:Long-term use of non-steroidal anti-inflammatory drugs and development of colorectal tumours: a systematic review and meta-analysis
Investigator(s):Huang J, Wong BCY
Department:Clinical Trials Ctr
Source(s) of Funding:Seed Funding Programme for Basic Research
Start Date:02/2004
Completion Date:01/2006
Abstract:
To systematically and critically review the literature on the relationship between long-term use of NSAIDs and development of colorectal tumors, and to estimate the magnitude of protection on colorectal polyps and cancer in people taking long-term NSAIDs.


List of Research Outputs



Researcher : Karlberg JPE

Project Title:Long-term health consequences of insults in early life
Investigator(s):Karlberg JPE, Low LCK
Department:Paediatrics & Adolescent Med
Source(s) of Funding:Health Services Research Fund - Full Grants
Start Date:11/1995
Abstract:
To understand the impact of early insults for health in adult-hood.


List of Research Outputs

Ansari M.T., Cheung B.M.Y. and Karlberg J.P.E., Prolonged Seated Immobility-associated Venous Coagulability in a Factor V Leiden Heterozygote:a Case-comparative Study, Blood Coagulation and Fibrinolysis. 2006, 17: 187-191.
Cheung B.M.Y., Lo J.L., Fong H.Y., Chan M.Y., Wong S.H., Wong C.M., Lam K.S.L., Lau C.P. and Karlberg J.P.E., Randomised controlled trial of qigong in the treatment of mild essential hypertension, J Hum Hypertens. 2005, 19: 697-704.
Karlberg J.P.E., Chairman, Oral II: Growth (O7-O10), Seventh International Symposium in Vivo Body Composition Studies - Linking structure & function, Southampton, UK, 7-9th September 2005. 2005.
Karlberg J.P.E., Clinical Trials in Hong Kong, China, MGH-nature-PKU Forum, Molecular Medicine and Biotechnology in China, Beijing, China, 16-18 October 2005. 2005.
Karlberg J.P.E., Current concepts and controversies about growth, body composition, and function, Seventh International Symposium in Vivo Body Composition Studies - Linking structure & function, Southampton, UK, 7-9th September 2005. 2005.
Karlberg J.P.E., Establishing a full-service Academic Clinical Trials Centre in Asia - pt 1, Spin. 2005, Summer 2005: 12-13.
Karlberg J.P.E., Establishing a full-service Academic Clinical Trials Centre in Asia - pt 2, SPIN. 2005, Autumn: 8-10.
Karlberg J.P.E., Facilitator, ChinaSCINet Investigator Meeting, Beijing, China, 15-16 October, 2005. 2005.
Karlberg J.P.E., Facilitator, ChinaSCINet Investigator Meeting, Hong Kong, 18 Decmber 2005. 2005.
Karlberg J.P.E., Growth Stunting as Mirrored by the ICP - Infancy, Childhood and Puberty - Growth Model, International Journal of Body Composition Research. 2006, 4 (1): 11-18.
Karlberg J.P.E., How to read the orthopaedic literature, Common Pitfalls in Orthopaedic Practice, The Third Hong Kong International Orthopaedic Forum, Hong Kong, 22-23 April 2006.
Karlberg J.P.E., IPC model of growth, Seventh International Symposium in Vivo Body Composition Studies - Linking structure & function, Southampton, UK, 7-9th September 2005. 2005.
Karlberg J.P.E., Obstacles and Opportunities for Collaborations among Academia, Industry and Government, First International Spinal Cord Injury Treatments & Trials Symposium (ISCITT), Hong Kong, 17-20 December 2005. 2005.
Karlberg J.P.E., Quality Assurance Measure within the China SCI Clinical Network, First International Spinal Cord Injury Treatments & Trials Symposium (ISCITT), Hong Kong, 17-20 December 2005. 2005.
Lin K., Fong D.Y.T., Zhu B. and Karlberg J.P.E., Environmental factors on the SARS epidemic: air temperature, passage of time and multiplicative effect of hospital infection, In: N. Noah, Epidemiology and Infection. UK, Cambridge University Press, 2006, 134: 223-230.


Researcher : Kwan CW

List of Research Outputs

Kwan C.W. and Fung T.W.K., Influence curves for factor loadings, British Journal of Mathematical and Statistical Psychology. U.K., The British Psychological Society, 2005, 58(2): 345-358.


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