Table 1.

Patient Characteristics by Annual Hospital Volume

<100≥100All Hospitals
%MR%MR%MR
All cases100.007.52100.006.28100.006.75
Patient characteristics
 Age
  <90 Days20.5918.6228.1013.5725.2315.15
  90 Days to 1 year20.529.4322.265.4821.596.91
  >1 Year58.892.9849.642.5053.172.70
 Sex
  Male52.768.5153.006.6052.917.33
  Female47.246.4147.005.9147.096.10
 Race
  White66.086.6972.876.0770.276.29
  Black21.8310.3716.667.0518.648.53
  Other12.086.9510.476.4711.096.67
Preop surgical risk factors
 Previous open heart operations
  One4.755.388.068.406.797.60
  Two or more0.950.001.634.171.373.06
 Previous closed heart operations
  One9.4211.6311.319.5810.5910.28
  Two or more2.599.862.355.772.447.43
 Severe cyanosis or severe hypoxia19.1317.94*21.6713.4420.7015.03
 Ventilator immediately preop10.0823.1912.5320.1811.5921.18
 Inotropic support preop3.6923.769.4120.387.2321.04
 Positive blood culture preop0.6622.220.7427.270.7125.49
 Arterial pH <7.25 preop2.2326.231.3335.591.6730.83
 Significant renal dysfunction0.8430.430.5226.090.6428.26
 Down syndrome7.8915.747.224.697.489.14*
 Significant extracardiac anomalies5.5920.26*6.5712.376.1915.09
 Congestive heart failure16.3914.7018.8911.4717.9412.60
 Pulmonary hypertension16.2116.67*15.6211.8515.8513.73
  • Note. Asterisks in the last column of the table denote a significant relationship between the patient characteristic and mortality (eg, the relationship between age groupings and mortality). Asterisks in the first column denote a significant difference in prevalence of the patient characteristic between hospitals with annual volumes below 100 and hospitals with annual volumes of 100 or more. Asterisks in the third column denote a significant difference in the mortality rate of patients of the patient characteristic between hospitals with annual volumes below 100 and hospitals with annual volumes of 100 or more.

  • * P < .05.

  • P < .01.

  • P < .001.