Volume criteria are poor predictors of inpatient mortality after esophagectomy, as many factors influence mortality for complex procedures.
Dr Michael Rodgers and colleagues from Oregon, USA quantified such factors and analyze the volume-outcome relationship for esophagectomy.
The research team conducted a retrospective review of the Nationwide Inpatient Sample database for esophagectomies.
The team performed multivariate analysis to identify patient and institution risk factors for death.
By using all reported volume thresholds, the researchers calculated the probability of choosing a provider with a low mortality.
| The national average mortality rate was 11%|
|Archives of Surgery|
The team assessed patients undergoing esophagectomy between 1988 and 2000, who were included in the Nationwide Inpatient Sample database.
The main outcome measure was inpatient mortality.
The researchers identified 8075 cases of esophagectomy; 3243 had complete data sets.
The national average mortality rate was 11%.
Independent risk factors for mortality included comorbidity, age, female sex, race, and surgeon volume.
Choosing a surgeon or hospital on the basis of a particular volume threshold had a modest influence on the probability of that provider having a low mortality.
The team noted that a low-volume hospital had a probability of 61% of having a mortality of less than 10%.
A high-volume hospital had a probability of 68%.
Dr Rodgers' team concludes, "Patient factors have a greater influence on inpatient mortality than case volume does."
"Although there is generally an inverse relationship between case volume and mortality, there is wide scatter between individual surgeons and hospitals, with a complex volume-outcome relationship."
"Using volume criteria alone to choose a provider may in some instances increase the risk of mortality."