Electronic medical records in primary care: management of duplicate records and a contribution to epidemiological studies.

Primary health care electronic medical records were analyzedin Rio de Janeiro for two chronic diseases, namely, hypertension and diabetes, in a population-based study with a cross-sectional epidemiological design that considered the Rio de Janeiro population enrolled in Family Health Teams. Calculation of the prevalence rate was stratified by gender and age group, and the condition of the disease was measured by family doctors in their visits using the ICD-10.Except for the last two age groups (75-79 years and 80 years and over), with apparent under-registration of the diagnosed cases, a positive association was found between prevalence rates and age in both genders. The generation of objective and reliable statistical information is fundamental for local management, allowing the evaluation of demographic dynamics and the peculiarities of each territory, and assisting in the planning and monitoring of the quality of Rio de Janeiro people's records registered in each family health unit. Thus, the regular management of duplicate records in the registered user roster is essential to minimize the over-registration of clinical cases reported in the electronic medical records.