Multinational Clinical Trials (multinational + clinical_trials)

Distribution by Scientific Domains


Selected Abstracts


From Hemicrania Lunaris to Hemicrania Continua: An Overview of the Revised International Classification of Headache Disorders

HEADACHE, Issue 7 2004
Jonathan P. Gladstone MD
The International Headache Society's (IHS) Classification of Headache Disorders, published in 1988, is largely responsible for stimulating the rapid scientific and therapeutic advances that have revolutionized the field of headache. By establishing consistent operational diagnostic criteria for primary and secondary headache disorders, the IHS Classification has facilitated epidemiological and genetic studies as well as the multinational clinical trials that provide the basis for our present treatment guidelines. Fifteen years after its original release, a revised 2nd edition has been unveiled. Modifications are small but significant. We hope to introduce clinicians to the salient changes in the 2nd edition by highlighting the newly included headache types, acknowledging the renamed headache types, and reviewing the modifications in diagnostic criteria for existing headache types. Physicians involved in the care of headache patients need to be aware of these changes and should continue to consult the IHS criteria to ensure accurate diagnosis, to continue to refine the diagnostic criteria, and to contribute to the body of knowledge necessary to make further advances in the classification as well as in the field of headache. [source]


Country specific cost comparisons from multinational clinical trials using empirical Bayesian shrinkage estimation: the Canadian ASSENT-3 economic analysis

HEALTH ECONOMICS, Issue 4 2005
Andrew R. Willan
Abstract The growing number of multinational clinical trials in which patient-level health care resource data are collected have raised the issue of which is the best approach for making inference for individual countries with respect to the between-treatment difference in mean cost. We describe and discuss the relative merits of three approaches. The first uses the random effects pooled estimate from all countries to estimate the difference for any particular country. The second approach estimates the difference using only the data from the specific country in question. Using empirical Bayes estimation a third approach estimates the country-specific difference using a variance-weighted linear sum of the estimates provided by the other two approaches. The approaches are illustrated and compared using the data from the ASSENT-3 trial. Copyright © 2005 John Wiley & Sons, Ltd. [source]


The impact of targeted training, a dedicated protocol and on-site training material in reducing observer variability of prostate and transition zone dimensions measured by transrectal ultrasonography, in multicentre multinational clinical trials of men with symptomatic benign prostatic enlargement

BJU INTERNATIONAL, Issue 1 2007
Philip S. Murphy
OBJECTIVE To assess the variability of a standardized protocol of transrectal ultrasonography (TRUS), with targeted training, and compare it to the variability in other multicentre clinical trials, as TRUS-estimated total prostate volume (TPV) and transition zone volume (TZV) are considered important efficacy endpoints in assessing new drug therapies for benign prostatic enlargement (BPE), but standardizing TRUS remains a challenge in such studies. PATIENTS AND METHODS In all, 174 patients with BPE in the placebo arm of a 30-centre clinical trial were analysed at baseline, 13 and 26 weeks with TRUS, to extract TPV and TZV values. All TRUS operators received training in the standardized methods, which was supplemented at the outset by a compact disc-based video. RESULTS The mean (sd) changes from baseline in TPV at 13 and 26 weeks were ,,2.9 (8.9) and ,1.9 (8.5) mL, respectively; the respective mean changes from baseline in TZV were ,1.2 (6.4) and +,0.7 (7.8) mL. For TPV, 80% of the measurements had differences of +,5.2 to ,13.4 mL at 13 weeks, and +,8.0 to ,,10.9 mL at 26 weeks. For TZV, 80% of the differences were +,5.8 to ,,7.4 at 13 weeks, and +,9.3 to ,6.5 mL at 26 weeks. CONCLUSION The performance of TRUS compared favourably with similar published multicentre studies, which we suggest relates in part to the careful implementation of the protocol. We showed that diligent implementation of a detailed protocol, supplemented by targeted training of investigators and provision of on-site training material, promoted consistent acquisition and successful derivation of key clinical trial endpoints. Quantifying the variability of such endpoints will enable us to track deployment quality for future clinical trials, and will ensure that trials are sufficiently powered to define small changes in prostate size. [source]