From: A systematic review of the impact of volume of surgery and specialization in Norwood procedure
Author (pub year) | N analysed | Hospital type | Surgeon volume | Â | Hospital volume | Model (adjustments) | |
---|---|---|---|---|---|---|---|
Chang 2002 [34] | 78 (1988–1992), 268 (1993–1997) | NI | NI |  |  | Hospital mortality | No model (volume treated as continuous variable; correlation coefficients) |
 |  |  |  |  | 1988-1992 | r = -0.20 (p < 0.01) |  |
 |  |  |  |  | 1993-1997 | r = -0.31 (p < 0.01) |  |
Gutgesell 2002 [35] | 1203 | NI | Â | NI | Â | Mortality | No model |
 |  |  |  |  | Low ≤ 50 | 50% |  |
 |  |  |  |  | High >50 | 40% |  |
Checchia 2005 [42] | 801 | NI | Â | Survival | Â | Survival | No model |
 |  |  | Low ≤4 | 49% | Low <16 | 48% |  |
 |  |  | High >4 | 69% | Medium 16-30 | 62% |  |
 |  |  |  |  | High >30 | 71% |  |
 |  |  |  |  |  | p = 0.08 |  |
 |  |  |  |  |  | Increase by 4% (95% CI 1%-7%) for every 10 additional procedures performed | Linear regression |
 |  |  |  | Trend for mortality p = 0.13 |  | Trend for mortality p = 0.02 | Volume treated as continuous variable |
 |  |  |  | Association of risk-unadjusted mortality |  | Association of risk-unadjusted mortality |  |
 |  |  |  | r2 = NR, p = 0.312 |  | r2 = 0.18, p = 0.02 |  |
 |  |  |  |  |  | Mean LOS survivors (SD) |  |
 |  |  |  |  | Low <16 | 36.5 ± 32.4 |  |
 |  |  |  |  | Medium 16-30 | 28.7 ± 8.4 |  |
 |  |  |  |  | High >30 | 29.4 ± 5.7 |  |
 |  |  |  |  |  | p > 0.05 |  |
 |  |  |  |  |  | Mean TTD (SD) |  |
 |  |  |  |  | Low <16 | 19.6 ± 33.2 |  |
 |  |  |  |  | Medium 16-30 | 12.2 ± 9.7 |  |
 |  |  |  |  | High >30 | 20.2 ± 9.6 |  |
 |  |  |  |  |  | p > 0.05 |  |
 |  |  |  |  |  | Median TTD (range) |  |
 |  |  |  |  | Low <16 | 19.2 (1–104) |  |
 |  |  |  |  | Medium 16-30 | 5.4 (1–13) |  |
 |  |  |  |  | High >30 | 7.8 (1–27) |  |
 |  |  |  |  |  | p > 0.05 |  |
Berry 2006 [33] | 754 (1997), 880 (2000) | Non-teaching vs. teaching | Hospital mortality | NI | Â | Hospital mortality | Logistic regression (teaching status, hospital volume, noncardiac structural anomaly, prematurity, low birth weight, aortic atresia, chromosomal anomaly) |
 |  | OR 2.6 (1.3 - 5.3) |  |  | Low | OR 3.1 (1.1 – 8.3) |  |
 |  |  |  |  | Mid-low | OR 2.0 (0.7 – 5.7) |  |
 |  |  |  |  | Mid-high | OR 1.0 (0.5 – 1.8) |  |
 |  |  |  |  | High | reference |  |
 |  |  |  |  | (Categories were determined from quartiles) |  |  |
Hirsch 2008 [36] | 624 | Â | Hospital mortality | Â | Â | Mortality | Â |
 |  | Urban teaching | 24.4% |  |  | Inverse association p = 0.0001 | Logistic regression (volume treated as continuous variable) |
 |  | Urban non-teach. | 32.2% |  |  |  |  |
 |  | Rural | 34.0% |  |  |  |  |
 |  | Unknown | 26.6% |  |  |  |  |
Welke 2009 [23] | 1154 | NI | NI |  | Mortality |  | Logistic regression (age, age-for-weight-and-sex z score, interaction between age and age-for-weight-and-sex z score, preoperative stay for more than 2 days; number of prior operations (0, 1, ≤2); renal failure or dialysis, acidosis, circulatory support or shock; preoperative ventilator support or tracheostomy; asplenia, polysplenia, or a22q11 deletion; DiGeorge syndrome; Down syndrome; procedure or procedure group; operation date |
 |  |  |  | Low <150 | OR 2.91 (1.98-4.28) |  |  |
 |  |  |  | Medium 150-249 | OR 1.59 (1.09-2.32) |  |  |
 |  |  |  | High 250-349 | OR 1.43 (1.06-1.95) |  |  |
 |  |  |  | Very high ≥350 | Reference |  |  |
 |  |  |  |  | Volume categories for pediatric cardiac surgery | p = 0.002 when hospital volume analysed as continuous variable (test of no volume mortality relationship) |  |
Karamlou 2010 [39] | 710 | NI | Â | Mortality | Â | Mortality | Hazard regression (Birth weight, age at operation, circulatory arrest time, ascending aortic dimension, reimplantation of the ascending aorta, shunt origin from the aorta) |
 |  |  |  | Increased cases per year (per case): -0.004 ± 0.007 (p = 0.49) [parameter estimate ± SE] |  | Increased cases per year (per case): -0.005 ± 0.01 (p = 0.38) [parameter estimate ± SE] |  |
McHugh 2010 [40] | 1949 | NI | NI | Â | Â | Hospital mortality | Logistic regression (?) |
 |  |  |  | Low <20 |  | OR 2.49 (1.51-4.07) |  |
 |  |  |  | Medium 20-64 |  | OR 1.75 (1.23-2.49) |  |
 |  |  |  | High >64 |  | Reference |  |
2555 | NI | Â | Hospital mortality | Â | Hospital mortality | Logistic regression (all patient characteristics, hospital volume/surgeon volume) | |
 |  |  | Low ≤5 | OR 1.47 (1.01-2.15 | Low ≤10 | OR 1.37 (0.92-2.05) |  |
 |  |  | Medium 6-10 | OR 1.26 (0.88-1.78) | Medium 11-20 | OR 1.20 (0.80-1.82) |  |
 |  |  | High >10 | Reference | High >20 | Reference |  |
 |  |  |  |  |  | OR 1.17 (1.01-1.35) for a twofold decrease in hospital volume | Volume treated as continuous variable |
Tabbutt 2012 [41] | 549 | NI | Â | Renal failure | Â | Renal failure | Logistic regression (anomalous pulmonary venous return, preoperative intubation, heart block, open sternum, volume) |
 |  |  | Low ≤5 | OR 0.31 (0.09-1.09) | Low ≤15 | OR 1.55 (0.53-4.58) |  |
 |  |  | Medium 6 to 10 | OR 0.90 (0.28-2.91) | Medium 16 to 20 | OR 0.44 (0.14-1.45) |  |
 |  |  | High 11 to 15 | OR 0.20 (0.06-0.61) | High 21 to 30 | OR 0.32 (0.11-0.91) |  |
 |  |  | Very high >15 | Reference | Very high >30 | Reference |  |
 |  |  |  | Log time to first extubation in days |  | Log time to first extubation in days | Linear regression (gestational age, left atrial decompression, TR preoperatively, duration of regional cerebral perfusion, ECMO, open sternum, duration of open sternum, operations after Norwood procedure, volume) |
 |  |  | Low ≤5 | 0.54 | Low ≤15 | -0.06 |  |
 |  |  | Medium 6 to 10 | 0.54 | Medium 16 to 20 | 0.31 |  |
 |  |  | High 11 to 15 | 0.40 | High 21 to 30 | 0.21 |  |
 |  |  | Very high >15 | Reference | Very high >30 | Reference |  |
 |  |  |  | Log length of ventilation in days |  | Log length of ventilation in days | Linear regression (gestational age, genetic abnormality, preoperative intubation, left atrial decompression, preoperative shock, TR preoperatively, age, open sternum, operations after Norwood procedure, volume) |
 |  |  | Low ≤5 | 0.33 | Low ≤15 | 0.004 |  |
 |  |  | Medium 6 to 10 | 0.27 | Medium 16 to 20 | 0.26 |  |
 |  |  | High 11 to 15 | 0.21 | High 21 to 30 | 0.12 |  |
 |  |  | Very high >15 | Reference | Very high >30 | Referene |  |
 |  |  |  |  |  | Log time hospital LOS in days | Linear regression (birth weight, genetic abnormality, preoperative intubation for shock, TR preoperative, duration of DHCA, operations after Norwood procedure, volume) |
 |  |  |  |  | Low ≤15 | 0.16 |  |
 |  |  |  |  | Medium 16 to 20 | 0.34 |  |
 |  |  |  |  | High 21 to 30 | -0.03 |  |
 |  |  |  |  | Very high >30 | reference |  |
 |  |  |  |  |  | Sepsis | Logistic regression (gestational age, AS/MS/VD, duration of DHCA, open sternum duration, volume) |
 |  |  |  |  | Low ≤15 | OR 2.28 (1.17-4.47) |  |
 |  |  |  |  | Medium 16 to 20 | OR 0.94 (0.40-2.19) |  |
 |  |  |  |  | High 21 to 30 | OR 0.64 (0.33-1.26) |  |
 |  |  |  |  | Very high >30 | reference |  |