RESUMO
OBJECTIVE: To identify factors that influence refusing to donating blood. MATERIAL AND METHODS: Prospective case and control study. Hospitalized patients' relatives were interviewed with a questionnaire to evaluate their knowledge of blood and personal attitudes toward blood donation. Cases were all relatives who did not donate blood and controls who did. RESULTS: A total of 121 individuals was studied, 30 cases and 91 controls. Age of the cases was 32.3 +/- 8.1 years and controls was 28.8 +/- 7.9 years (p = 0.04). Risk factors were female sex (OR = 6.3; 95%CI 2.4 to 17.1), being married (OR = 3.7 95%CI 1.3 to 10.5). No differences were present between the two groups in level of knowledge concerning blood. The average of positive attitudes toward blood donation was greater among relatives who donated blood (cases 5.9 +/- 1.6; controls 6.4 +/- 1.2; P = 0.049). Among the attitudes that influence refusing to donate blood were fear of getting dizzy at the sight of blood (OR = 5.2, 95%CI 1.3-21.4), fear of donating blood (OR = 2.2, 95%C, 0.8-6.0), and getting nervous at the sight of blood (OR = 4.1, 95%CI% 1.5-10.9). CONCLUSIONS: Among patient's relatives who donate blood positive personal attitudes toward blood donation have more weight than knowledge on the subject.