PT  - JOURNAL ARTICLE
AU  - G M Fitzmaurice
TI  - ADJUSTING FOR CENTRE IN MULTICENTRE STUDIES
DP  - 2008 Nov 01
TA  - Archives of Disease in Childhood
PG  - espr25--espr25
VI  - 93
IP  - Suppl 2
4099  - http://adc.bmj.com/content/93/Suppl_2/espr25.short
4100  - http://adc.bmj.com/content/93/Suppl_2/espr25.full
SO  - Arch Dis Child2008 Nov 01; 93
AB  - Objective: A multicentre study is a single study involving several centres (or investigators) where the combined data contributed by all centres is intended to be analysed as a whole. In general, multicentre studies are conducted at several centres either to increase the number of participants that would otherwise be available at any single centre, or to assess the effectiveness of the treatment or intervention across a broader range of settings. By performing the study in multiple centres, and often in multiple countries, a multicentre study design allows for the sampling of a broader patient population and the completion of the study within a reasonable timeframe. Typically, differences between centres (eg, different study investigators, differences in the centre patient populations, differences in medical care practices among centres) may result in extra variability in the treatment effect estimates. This extra variation must be properly accounted for in the analysis. In this presentation, we consider some alternative statistical methods for the analysis of data collected from multicentre studies. We highlight important distinctions between alternative methods and make some recommendations concerning appropriate methods of analysis.