International Journal of Medical Research & Health Sciences
  • Year: 2015
  • Volume: 4
  • Issue: 3

Prevalence of chronic diseases in individuals assisted by the family health program in Niteroi, Brazil: evaluation of selection bias and protocol

  • Author:
  • G Rosa Maria Luiza1,, T Mesquita Evandro2, L Jorge Antonio Jose2, MS Correia Dayse3, R Lugon Josemir2, HC Kang4, EMs Yokoo5, V Wahrlich5
  • Total Page Count: 10
  • Page Number: 587 to 596

1Professor, Department of Epidemiology and Biostatistics, Universidade Federal Fluminense, Niter 6i, Rio de Janeiro, Brazil

2Professor, Department of Clinical Medicine, Universidade Federal Fluminense, Niter6i, Estado do Rio de Janeiro, Brazil

3Professor, Department of Nursing Fundamentals and Administration, Universidade Federal Fluminense, Niter6i, Rio de Janeiro, Brazil

4Professor, Department of Pathology, Universidade Federal Fluminense, Niter6i, Rio de Janeiro, Brazil

5Professor, Department of Social Nutrition, Universidade Federal Fluminense, Niter6i, Rio de Janeiro, Brazil

*Corresponding author: Maria Luiza Garcia Rosa Rua Marques de Parana 303, Centro Niter6i, Rio de Janeiro, Brasil CEP 24033-900 -e-mail: mluizagr@gmail.com

Online published on 29 July, 2015.

Abstract

The strategy of the Family Health Program has been used as an alternative scenario for prevalence studies. This study intended to present the protocol of the Digitalis Study (DS), prevalence study of chronic diseases, to assess sources of possible selection bias and estimate their impact on the prevalence of self-reported hypertension, diabetes, and myocardial infarction.

Randomization was performed between 38 160 registered individuals with 45 to 99 years by the Family Health Program. Differences between the sources of selection bias (non-acceptance, non-attendance, substitutions) were observed for gender and age.

Of the 1,190 residents contacted, 67.1% agreed to participate. There were 144 residents who were not randomly selected but whose participation was confirmed (substitutes). Women and individuals in the intermediate age groups and the prevalence of hypertension were higher among substitutes compared with the randomly selected individuals.

The approach of the DS was adequate for the purposes of estimating prevalences, but there was a significant percentage of non-participation. The randomization strategy did not assume outdated records; alternative schedules for visits were not provided for; follow-up at the invitation stage was not sufficient to prevent substitutions and the inclusion of substitutes with a higher prevalence of hypertension.

Keywords

Epidemiological Methods, Epidemiology of chronic non communicable diseases, Kidney disease, Heart Failure