STS publicly reports risk-adjusted participant group outcomes and composite quality ratings for the following surgical procedures:
Resection for primary lung cancer
Esophagectomy for esophageal cancer
Risk Adjustment
Risk adjustment allows STS database participants to compare their performance to other groups, such as the overall STS cohort, other participants, or by region or state. A participant’s case mix refers to the types of patients being treated, including their age, health conditions, how serious their heart problems are, and other factors. By accounting for and controlling patient risk factors present before surgery, risk adjustment “levels the playing field” as best as possible. Specifically, some hospitals care for more ill patients, and those patients are at greater risk of dying due to their underlying conditions, not necessarily because of the care they receive. Risk adjustment accounts for these risk factors. Unadjusted event rates are not used for these comparisons because they may be affected by variation in patient case mix and disease severity across participants.
Using risk adjustment provides a more accurate reflection of a participant’s performance relative to a reference cohort with similar patient characteristics. Direct comparisons between the risk-adjusted mortality rates of two individual participants are generally inadvisable unless their patient populations are relatively similar.
Composite quality ratings, patient populations, and reporting periods
Resection for primary lung cancer
| Overview | The STS resection for primary lung cancer composite includes two domains: 1) absence of operative mortality; and 2) absence of major morbidity. Both domains are risk adjusted. Participants receive scores and ratings for each of the two domains, plus overall composite results. In addition to receiving a numeric score, participants are assigned performance rating categories designated as worse than expected, as expected, or better than expected. |
| Patient population | Patients aged 18 years or older with a diagnosis of primary lung cancer who underwent a pulmonary resection (i.e., wedge resection, segmentectomy, lobectomy, sleeve lobectomy, bilobectomy, pneumonectomy). |
| Reporting period | Three years (36 months). |
Esophagectomy for esophageal cancer
| Overview | The STS esophagectomy composite score includes two domains: 1) absence of operative mortality; and 2) absence of major morbidity. Both domains are risk adjusted. Participants receive scores and ratings for each of the two domains, plus an overall composite results. In addition to receiving a numeric score, participants are assigned performance rating categories designated as worse than expected, as expected, or better than expected. |
| Patient population | Patients aged 18 years or older with a diagnosis of esophageal cancer who underwent an esophagectomy. |
| Reporting period | Three years (36 months). |
Participant performance compared to NIS outcomes
The STS recognizes that GTSD participant outcomes for resections for lung cancer are better than national averages. Therefore, an STS participant’s results are compared with both the STS GTSD and national outcomes.
The National Inpatient Sample (NIS) was selected as the database to best represent national outcomes, as it is the largest, all-payer inpatient database available in the United States, representing a 20% stratified sample of all hospital discharges from nonfederal facilities. Maintained by the Agency for Healthcare Research and Quality, NIS includes almost 8 million inpatient hospital discharge abstracts collected annually for patients of all ages and all sources of insurance. Each discharge record includes a weight that represents the relative proportion of the total U.S. hospital patient population accounted for by that record. This dataset is broadly representative of individuals in the U.S. population who were hospitalized that year and is the most generalizable data to represent national lung cancer resection outcomes.
STS and NIS Comparison Outcomes
There are two outcomes that can be directly compared between STS and NIS.
The first outcome is discharge mortality. Although STS typically reports operative mortality, which includes 30-day outcomes, discharge mortality is collected and directly comparable with NIS data. Discharge mortality is defined as any postoperative death occurring prior to hospital discharge.
The second outcome is postoperative length of stay. Length of stay is reported in days in both databases.
Unfortunately, postoperative complications reported in the STS GTSD cannot be directly compared with the NIS, as the latter uses administrative ICD-9 and ICD-10 codes, which are not directly comparable with the clinical definitions for postoperative complications in GTSD.