Addressing the issues that arise in analysing multicentre cost data, with application to a multinational study

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jhealeco.2006.02.001 Byline: Simon G. Thompson (a), Richard M. Nixon (a), Richard Grieve (b) Keywords: Cost data; Multinational studies; Health economic evaluation; Generalised linear models; Hierarchical models Abstract: Differences in the mean, spread and skewness of cost data collected from different countries present problems for analysis and interpretation. Here we develop generalised linear multilevel models to estimate the effects of patient and national characteristics on costs. Using gamma distributions and multiplicative effects for patient characteristics fitted the data better than models which assumed normal distributions or estimated additive effects. A multilevel gamma model is employed to allow for heterogeneity in the effects of patient case-mix across centres. Analysis of multinational cost data must recognise differences in mean, spread and skewness across centres, as well as the data's hierarchical structure. Author Affiliation: (a) MRC Biostatistics Unit, Institute of Public Health, Cambridge, UK (b) Health Services Research Unit, London School of Hygiene and Tropical Medicine, London, UK Article History: Received 17 March 2005; Revised 2 February 2006; Accepted 6 February 2006