Surgical complications – CMS Patient Safety Indicators
Measures of serious complications are drawn from the CMS Patient Safety Indicators (PSIs). The overall score for serious complications is based on how often adult patients had certain serious, but potentially preventable, complications related to medical or surgical inpatient hospital care. This composite (or summary) measure – Patient Safety and Adverse Events Composite – is based on the following measures:
- (PSI 3) Pressure sores (pressure ulcers)
- (PSI 6) Collapsed lung that results from medical treatment (iatrogenic pneumothorax)
- (PSI 8) Broken hip from a fall after surgery (in-hospital fall with hip fracture)
- (PSI 9) Bleeding or bruising during surgery (perioperative hemorrhage or hematoma)
- (PSI 10) Kidney and diabetic complications after surgery (postoperative acute kidney injury requiring dialysis)
- (PSI 11) Respiratory failure after surgery (postoperative respiratory failure)
- (PSI 12) Blood clots, in the lung or a large vein, after surgery (perioperative pulmonary embolism or deep vein thrombosis)
- (PSI 13) Blood stream infection after surgery (postoperative sepsis)
- (PSI 14) A wound that splits open after surgery (postoperative wound dehiscence)
- (PSI 15) Accidental cuts and tears (unrecognized abdominopelvic accidental puncture or laceration)
CMS also reports the following standalone measure:
(PSI 4) Death rate among surgical inpatients with treatable complications
Which patients are included
The measures of serious complications apply only to Medicare beneficiaries enrolled in Original Medicare who were discharged from a hospital that was paid through the Inpatient Prospective Payment System (IPPS) after the beneficiary had an inpatient stay. Non-Medicare patients and beneficiaries enrolled in Medicare managed care plans are also excluded from the data.
Where the information comes from
CMS calculates the patient safety indicators from the claims hospitals submit for Medicare beneficiaries enrolled in Original Medicare. Before risk adjustment and smoothing (see “Risk Adjustment” section below), the rate for each PSI is calculated by dividing the actual number of outcomes at each hospital by the number of eligible discharges for that measure at each hospital, multiplied by 1,000; the CMS PSI 90 composite value is the weighted average of the component indicators. PSI data are only calculated for hospitals that are paid through the IPPS, which excludes critical access hospitals (CAHs), long-term care hospitals (LTCHs), cancer hospitals, children's inpatient facilities, rural health clinics, federally qualified health centers, inpatient psychiatric hospitals, inpatient rehabilitation facilities, Veterans Administration/ Department of Defense hospitals, and religious, non-medical health care institutions.
The measures of serious complications reported on Hospital Compare are risk adjusted to account for differences in hospital patients’ characteristics. In addition, the rates reported on Hospital Compare are “smoothed” to reflect the fact that measures for small hospitals are measured less accurately (i.e., are less reliable) than for larger hospitals.
Comparing individual hospital rates to benchmarks
For the composite measure as well as CMS PSI 4, CMS assigns comparative performance categories. If the interval estimate includes and/or overlaps with the national composite value, the hospital’s performance is in the “no different than national rate/value” category. If the entire interval estimate is below the national composite rate/value, then the hospital is performing “better than national rate/value.” If the entire interval estimate is above the national composite rate/value, it is “worse than national rate/value.” For the individual measures, Hospital Compare displays information on each hospital’s performance category, number of cases, rate, and confidence interval.
For the technical specifications for CMS Patient Safety Indicators, information about Medicare's calculations, and reporting of these claims-based measures: