Page 16 - Ovarian Cancer Surgery - Quality Indicators
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its statistical significance when other variables were included in the model.
It should be noted that the available evidence concerning the hospital volume presented above
showed great heterogeneity and has to be interpreted cautiously notably because 1 there are
variations in hospital volume definitions among identified studies, 2 th ere are variations in the
sample sizes of the studies and the lack of adequate risk adjustment strategies made it difficult to
distinguish between effects of separate variables, 3 none of the studies controlled for clustering
i.e., the effects of the referral pattern of a given physician or institution that might distort the effects
of selected variables, and 4 the decision to repeat a surgery is partially subjective, and the answer
may lie in clinical decision-making. Factors that contribute to the decision to perform repeat surgery
include the patient’s age, other comorbidities, opportunity to avoid adjuvant therapy because of the
information from a subsequent staging surgery, the strength of the conviction that optimal debulking
improves survival, physician bias based on who performed the initial surgery and patient preference.
Impact of physician volume on survival: among the studies included in the systematic review LoE 2-
published by du Bois et al.209, 3 studies112,210,225 addressed the effect of surgeon volume on survival.
Two studies210,225 reported that surgeon volume did not impact survival in multivariate analyses. The
third study112 described an association between surgeon volume and survival after controlling for
case mix Table 5. Two original studies 217,220 were also identified and showed that surgery by a high-
volume surgeon did not reduce significantly the mortality risk in multivariate analyses.
Impact of physician volume on the risk of in-hospital death: Bristow et al.226 reported that ovarian LoE 2-
cancer surgery performed by a high-volume surgeon ≥ 10/y was independently associated with a
69% reduction in the risk of in-hospital death OR = 0.31, 95% CI = 0.16 -0.61, p = 0.001.
Impact of physician volume on surgical outcome: Goff et al.227 described an advantage for high- LoE 2-
volume surgeons ≥ 10/y in multivariate analysis after adjustment for age, race, stage,
comorbidities, median household income, state, location of hospital, obstetrician/gynecologists per
100,000 population in country of residence, teaching status and hospital ovarian cancer volume
Table 6. A second study 220 was identified and confirmed that high-volume surgeon > 12/y
significantly affected the outcome of debulking residual tumour ≤ 1 cm, logistic regression analysis
adjusted for stage and age.
It should be noted that these results concerning the impact of surgeon volume on surgical outcome
must take into account that a potential interobserver bias in assessing the diameter of residual disease
may influence the results.
Impact of surgeon volume on the likelihood of repeat surgery: Elit et al.217 assessed whether the LoE 2-
surgeon procedure volume determined the likelihood of unnecessary repeated surgery. Univariate
analysis showed that the surgeon procedure volume < 10 per year was found to be significantly
associated with a higher risk of repeat surgery 3 -9/y: RR = 7.63, 95% CI = 3.29-17.69, p < 0.05; 1-
2/y: RR = 10.04, 95% CI = 4.44-22.71, p < 0.05. However, this volume-outcome association lost its
statistical significance in when other variables were included in the model.
It should be noted that the available evidence concerning the surgeon volume presented above
showed great heterogeneity and has to be interpreted cautiously notably because 1 there are
variations in physician volume definitions among identified studies, 2 th ere are variations in the
sample sizes of the studies and the lack of adequate risk adjustment strategies made it difficult to
distinguish between effects of separate variables, and 3 none of the studies controlled for clustering
i.e., the effects of the referral pattern of a given physician or institution that might distort the effects
of selected variables, and 4 the decision to repeat a surgery is partially subjective, and the answer
may lie in clinical decision-making. Factors that contribute to the decision to perform repeat surgery
include the patient’s age, other comorbidities, opportunity to avoid adjuvant therapy because of the
OVARIAN CANCER SURGERY - QUALITY INDICATORS
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