Evaluation of community-intervention trials via generalized linear mixed models

Biometrics. 2004 Dec;60(4):1043-52. doi: 10.1111/j.0006-341X.2004.00260.x.

Abstract

In community-intervention trials, communities, rather than individuals, are randomized to experimental arms. Generalized linear mixed models offer a flexible parametric framework for the evaluation of community-intervention trials, incorporating both systematic and random variations at the community and individual levels. We propose here a simple two-stage inference method for generalized linear mixed models, specifically tailored to the analysis of community-intervention trials. In the first stage, community-specific random effects are estimated from individual-level data, adjusting for the effects of individual-level covariates. This reduces the model approximately to a linear mixed model with the unit of analysis being community. Because the number of communities is typically small in community-intervention studies, we apply the small-sample inference method of Kenward and Roger (1997, Biometrics53, 983-997) to the linear mixed model of second stage. We show by simulation that, under typical settings of community-intervention studies, the proposed approach improves the inference on the intervention-effect parameter uniformly over both the linearized mixed-effect approach and the adaptive Gaussian quadrature approach for generalized linear mixed models. This work is motivated by a series of large randomized trials that test community interventions for promoting cancer preventive lifestyles and behaviors.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Biometry
  • Community Health Services / statistics & numerical data
  • Community-Institutional Relations
  • Cross-Sectional Studies
  • Data Collection
  • Diet
  • Fruit
  • Health Promotion / statistics & numerical data
  • Humans
  • Linear Models*
  • Public Health
  • Randomized Controlled Trials as Topic / statistics & numerical data*
  • Vegetables
  • Washington