title: [Statistical analysis for count data: use of healthcare services applications].
abstract: OBJECTIVE
  To describe some of the statistical models for the study of count variables in the context of the use of health services.
  
  
  METHODS
  We used the Seguro Popular Evaluation Survey to estimate the effect of Seguro Popular on the frequency of use of outpatient health services, using Poisson regression models and negative binomial, zero-inflated negative binomial and the hurdle negative binomial models. We used the Akaike Information Criterion (AIC) to define the best model.
  
  
  RESULTS
  Results show that the best statistical approach to model the use of health services is the hurdle model, taking into account both the main theoretical assumptions and the statistical results of the AIC.
  
  
  CONCLUSIONS
  The modelling of count data requires the application of statistical models to model data dispersion; in the presence of an excess of zeros, the hurdle model is an appropriate statistical option.
authors: Centro de Investigación en Evaluación y Encuestas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors: Aarón
authors: A
authors: Salinas-Rodríguez
authors: Betty
authors: B
authors: Manrique-Espinoza
authors: Sandra G
authors: SG
authors: Sosa-Rubí
mesh_terms: D006296:Health Services / Q000706:statistics & numerical data*; D008800:Mexico; D015233:Models, Statistical; D012044:Regression Analysis