Understanding of the role of serum creatinine in a subset of the Brazilian population.

Introduction: Chronic kidney disease is usually asymptomatic, and its diagnosis depends on laboratory tests, with emphasis on serum creatinine and proteinuria.

Objective: To assess knowledge on the role of serum creatinine as a biomarker of kidney function in a sample of the Brazilian population.

Method: Cross-sectional observational study conducted in São Paulo (SP, Brazil), in which a random adult population was interviewed.

Results: A total of 1138 subjects were interviewed, with a median age of 36 years old (27-52); 55.1% were female. Regarding the "creatinine" biomarker, 40.6% stated they had never performed such a test. When asked about their knowledge on the usefulness of this exam, only 19.6% knew its function. The other responses were "I don't know" (71.6%), evaluating heart function (0.9%) and liver function (7.8%). Of those who reported they had already taken a creatinine test, only 29.4% correctly identified the role of creatinine. When dividing the groups into "knows" and "does not know" the function of creatinine, a statistically significant difference (p < 0.05) was observed regarding level of education, female sex, being a healthcare student/worker, having ever measured creatinine, knowing someone with kidney disease and older age. In the multivariate analysis, the main variable related to knowing the creatinine role was having previously taken the test (OR 5.16; 95% CI 3.16-8.43, p < 0.001).

Conclusion: There is a significant lack of knowledge about creatinine and its use in checkups. The results indicate that greater efforts are needed from healthcare professionals to raise awareness on the role of serum creatinine.