Titre : | A cautionary note regarding count models of alcohol consumption in randomized controlled trials (2007) |
Auteurs : | N. J. HORTON ; E. KIM ; R. SAITZ |
Type de document : | Article : Périodique |
Dans : | BMC Medical Research Methodology (Vol.7, n°9, February 2007) |
Article en page(s) : | 9 p. |
Langues: | Anglais |
Discipline : | EPI (Epidémiologie / Epidemiology) |
Mots-clés : |
Thésaurus mots-clés ALCOOL ; ETUDE RANDOMISEE ; MODELE STATISTIQUE ; CONSOMMATION ; METHODE |
Résumé : | BACKGROUND: Alcohol consumption is commonly used as a primary outcome in randomized alcohol treatment studies. The distribution of alcohol consumption is highly skewed, particularly in subjects with alcohol dependence. METHODS: In this paper, we will consider the use of count models for outcomes in a randomized clinical trial setting. These include the Poisson, over-dispersed Poisson, negative binomial, zero-inflated Poisson and zero-inflated negative binomial. We compare the Type-I error rate of these methods in a series of simulation studies of a randomized clinical trial, and apply the methods to the ASAP (Addressing the Spectrum of Alcohol Problems) trial. RESULTS: Standard Poisson models provide a poor fit for alcohol consumption data from our motivating example, and did not preserve Type-I error rates for the randomized group comparison when the true distribution was over-dispersed Poisson. For the ASAP trial, where the distribution of alcohol consumption featured extensive over-dispersion, there was little indication of significant randomization group differences, except when the standard Poisson model was fit. CONCLUSION: As with any analysis, it is important to choose appropriate statistical models. In simulation studies and in the motivating example, the standard Poisson was not robust when fit to over-dispersed count data, and did not maintain the appropriate Type-I error rate. To appropriately model alcohol consumption, more flexible count models should be routinely employed. (Author's abstract) |
Domaine : | Alcool / Alcohol |
Refs biblio. : | 15 |
Affiliation : | Department of Mathematics and Statistics, Smith College, Northampton, MA, USA |
Centre Emetteur : | 13 OFDT |
Cote : | A03496 |
Lien : | http://dx.doi.org/10.1186/1471-2288-7-9 |
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