Reference values for blood count laboratory tests in the Brazilian adult population, national health survey

Abstract

Objective: To describe reference values for blood counts obtained from laboratory tests in the Brazilian adult population according to laboratory results from the National Health Survey (Pesquisa Nacional de Saúde — PNS), by gender, age group and skin color. Methods: The initial sample consisted of 8,952 adults. To determine the reference values, individuals with prior diseases and outliers were excluded. Mean values, standard deviation and limits were stratified by gender, age group and skin color. Results: For red blood cells, men presented a mean value of 5.0 million per mm3 (limits: 4.3–5.8) and women, 4.5 million per mm3 (limits: 3.9–5.1). Hemoglobin levels were higher among men with a mean of 14.9 g/dL (13.0–16.9), and in women, 13.2 g/dL (11.5–14.9). The mean number of white blood cells among men was 6.142/mm3 (2.843–9.440) and 6.426/mm3 (2.883–9.969) for women. Other parameters showed close values between the genders. Regarding age groups and skin color, mean values, standard deviation and limits of the exams presented small variations. Conclusion: Hematological reference values based on the national survey allow for the establishment of specific reference limits for gender, age and skin color. The results presented here may contribute to the establishment of better evidence and criteria for the care, diagnosis and treatment of diseases.