[Volume and quality of care in coronary artery bypass grafting in Brazil]. / Avaliação da relação entre volume de procedimentos e a qualidade do cuidado: o caso de cirurgia coronariana no Brasil.

There is often a negative association between the volume of medical procedures and hospital mortality rates. The objective of this study is to determine whether this association is observed in Brazilian hospitals performing coronary artery bypass grafts (CABG) that were financed by the Ministry of Health. CABG surgeries performed from 1996 to 1998 were analyzed. Data were collected from the Ministry of Health Hospital Information System. The statistical procedure utilized was the Cox survival analysis. Hospitals were grouped in classes of volume of CABG performed. The model was adjusted to the severity of cases (risk of dying). From January 1996 to December 1998 the Ministry of Health reimbursed 41,989 CABG procedures in 131 hospitals. The overall hospital mortality rate was 7.2%. A gradient was observed in the mortality rates. The severity-adjusted risk of dying in the group of hospitals performing more procedures was lower than in the group performing fewer operations. It is recommended that the Ministry of Health strongly consider regionalized concentration of services to perform CABG.