Prevalence of anemia in patients with chronic kidney disease attended at a nephrology outpatient clinic and its association with the outcome of renal replacement therapy over five years: a retrospective cohort study, Municipality of São Paulo, 2010-2018.

OBJECTIVE

To evaluate the prevalence of anemia in patients with chronic kidney disease and its association with the need for renal replacement therapy for five years in a specialized outpatient clinic.

METHODS

Retrospective cohort study that included patients admitted to a nephrology outpatient clinic between 2010 and 2018 in the municipality of São Paulo. Demographic, clinical, and laboratory data were analyzed using frequencies and absolute values. Anemia was defined as a hemoglobin concentration <13 g/dL for men and <12 g/dL for women. Clinical data and the need for renal replacement therapy over five years between patients with and without anemia at admission were compared. For statistical analyses, Pearson's chi-square and Student's t or Mann-Whitney U tests, Kaplan-Meier curve with log-rank test, and survival analysis using Cox regression were used.

RESULTS

The study included 534 patients, 41.8% of whom were diagnosed with anemia at admission. Hypertension (35.2%) and diabetes (27.5%) were the leading causes of chronic kidney disease. In five years, 4.1% progressed to renal replacement therapy. Anemia at admission was associated with a higher risk of the outcome (hazard ratio - HR 3.24; 95% confidence interval-95%CI 1.38; 7.61). Hemoglobin level was an independent predictor of outcome (HR 0.766; 95%CI 0.593; 0.989).

CONCLUSION

A high prevalence of anemia in chronic kidney disease was found in patients from Primary Health Care. Hemoglobin level was an independent variable associated with the outcome.