Skip to main content

Table 5 Outcomes explored by the reviewed studies

From: Assessing the hospital volume-outcome relationship in surgery: a scoping review

Mortality Length of stay Hospital readmission Cost Surgical complications General complications Oncological issues Characteristics of the hospital stay (continuous) Quality indicators
Death occurring during a pre-defined time period (1, 7, 30, 60, 90 or 180 days, 1, 2, 3 or 5 years) Continuous length of stay (from admission to discharge) Readmission for any cause during a pre-defined time period (2 weeks, 30 days, 6 weeks, 90 days, or 1, 2, or 3 years) Costs billed by the hospital, excluding physicians’ fees Severity of the complication: Clavien-Dindo grade III or higher At least one complication within a specific time period (in-hospital stay, 30 or 90 days, 75th percentile of the length of stay) or the complication rate successful surgery: positive surgical margins (circumferential), number of resected lymph nodes, complete resection or not, restorative surgery performed or not. Being in the intensive care unit (ICU) for longer than a specific time (1 or 2 days) or requiring organ support (mechanical ventilation or dialysis) Patient safety indicators
Failure-to-rescue rates: death after a major complication within a pre-defined period of time (30 days, 90-days, in-hospital) Continuous post-surgical length of stay (from surgery to discharge) Readmission for a specific cause (aseptic revision, rescue surgery as a full procedure after a partial one, implant revision) Sum of all costs except the cost of initial surgery (considered to be similar across all centres) Abscess, haemorrhage, or anastomotic leakage Major complications, defined as the need for surgical intervention or organ supply within a specific time period (in-hospital, 14 days) Recurrence of cancer: local recurrence, distant metastases, and vital status Routine discharge versus nonroutine discharge (i.e. to rehabilitation, home, or a care home) Surgical reconstruction rate
Ratio between observed and expected (O/E) deaths Continuous length of uninterrupted institutional care A composite of readmission to an acute care hospital for any cause and all-cause death within a specific time period Excess costs, defined as those above a defined cut-off (median, 75th percentile, etc.) Surgical site bleeding, need for transfusion, or transfusion volume Kidney failure or urinary tract infection Risk ratios for positive margins Time to surgery/transplantation or the door-to-balloon time Proportion of pneumectomies
Risk-adjusted mortality: the O/E ratio multiplied by the overall mortality rate for the cohort Prolonged length of stay: longer than a cut-off (insurance period, median value, 75th percentile, 90th percentile, etc.) Risk-adjusted readmission rate, the O/E ratio multiplied by the overall readmission rate for the cohort Cost per day of treatment: the total cost divided by the length of stay Perforation or laceration (bowel, oesophageal, ureteral, rectum, bladder, nerve, etc.) One of the eight emergency general surgery complications Time to recurrence or progression-free survival time Duration of treatment with antibiotics Amputation-free survival
Hospital-standardized mortality ratio   Unplanned readmission to the same hospital Cost-per-episode of surgery, adjusted for wage index Surgical site infection, wound infection Sepsis, septicaemia, shock, or prosthesis or implant infection   Travel time or distance to hospital Sphincter preservation
Disease-related death (cancer, surgery, or sepsis related)   Readmission rate for each subspecialty or diagnosis Cost-per-episode of surgery, adjusted for inflation Major amputation (lower limb, organ) Pulmonary embolism, deep venous thrombosis   Number of hours requiring organ support Survival of thumb replantation
Time-to-death, as the time interval between surgery and death   Reoperation during the initial hospital stay    Neurological or cerebrovascular complications   Duration of surgery  
Post-discharge mortality      Need for a permanent pacemaker   Duration of anaesthesia  
In-hospital mortality      Respiratory failure or arrest    
      Cardiac arrest or myocardial infarction    
  1. NB: the outcomes are not listed in a particular order