Table 1

Number of cases, raw 30-day mortality rate and case mix variables shown by individual year of operation from 2000 to 2010

Year2000200120022003200420052006200720082009/2010
Number of surgery episodes2283292533863697350536553802373337753939*
Missing outcome†227 (9%)193 (6.2%)61 (1.8%)16 (0.4%)11 (0.3%)07 (0.2%)8 (0.2%)9 (0.2%)138 (2.3%)
Mortality % (95% CI)4.3 (3.6 to 5.1)3.6 (2.9 to 4.3)3.7 (3.3 to 4.4)3.3 (2.7 to 3.8)2.7 (2.2 to 3.3)3.3 (2.7 to 3.8)2.9 (2.4 to 3.5)3.0 (2.5 to 3.6)3.4 (2.8 to 3.9)2.6 (2.2 to 3.0)
High-risk diagnoses (%)‡152 (6.7)202 (6.9)227 (6.7)278 (7.5)263 (7.5)305 (8.3)363 (9.6)376 (10.1)367 (9.7)556 (9.5)
Low weight (%)§161 (8.1)203 (7.7)329 (10.2)281 (8.2)321 (9.7)354 (10.3)381 (10.3)329 (9.0)405 (11.0)592 (10.4)
Functionally univentricular heart (%)302 (13.2)377 (12.9)432 (12.8)521 (14.1)497 (14.2)538 (14.7)603 (15.9)629 (16.9)632 (16.7)961 (16.3)
Risk band 4 (%)139 (6.8)166 (6.4)190 (6.4)215 (6.6)214 (6.8)213 (6.8)258 (7.8)256 (8.3)222 (7.3)272 (7.2)
Children (%)929 (40.7)1233 (42.2)1458 (43.1)1654 (44.7)1466 (41.8)1494 (40.9)1553 (40.9)1591 (42.6)1521 (40.3)2341 (39.8)
Infants (%)813 (35.6)1055 (36.1)1166 (34.4)1279 (34.6)1292 (36.9)1429 (39.0)1447 (38.0)1359 (36.4)1463 (38.8)2309 (39.2)
Neonates (%)541 (23.7)637 (21.8)762 (22.5)764 (20.7)747 (21.3)732 (20.1)802 (21.1)783 (21.0)791 (21.0)1230 (21.0)
  • *Given that the year 2010 contained a truncated amount of data, as stated in Methods, the years 2009/2010 were combined for analyses. This cell relates to 2009 only, whereas data in lower cells relate to 2009/2010.

  • †Records with missing outcome listed in this row are excluded from the rest of the analyses.

  • ‡Overall there were 1270 records with a missing diagnosis that were excluded from this row of data.

  • §Overall there were 1836 records with missing weight that were excluded from this row of data.