. 2020 Jan 9;72(1):90–98. doi: 10.1093/cid/ciaa012

Table 1.

Eligible Covariates for Each Risk Adjustment Model

CMS	HCA-Adapted-CMS	Expanded Claims	Claims Plus EHR
Age	Age	Age	Age
ASA score	ASA score	ASA score	ASA score
Diabetes status	Diabetes status	Diabetes status	Diabetes status
Body mass index	Body mass index	Body mass index	Body mass index
Use of primary closure	Use of primary closure	Use of primary closure	Use of primary closure
Oncology hospital	Oncology hospital	Oncology hospital	Oncology hospital
Sex	Sex	Sex	Sex
…	…	Charlson/Elixhauser comorbidities^a	Charlson/Elixhauser comorbidities^a
…	…	Concomitant colon procedures^a	Concomitant colon procedures^a
…	…	Concomitant noncolon intraabdominal procedures^a	Concomitant noncolon intraabdominal procedures^a
…	…	…	Use of anesthesia ^b
…	…	…	Procedure duration^b
…	…	…	Laparoscopic technique^b
…	…	…	Medical school affiliation^b
…	…	…	Hospital size ≥/<500 beds^b
…	…	…	Wound class^b
…	…	…	Emergency surgery^b
…	…	…	Smoking status (current, former, or never)
…	…	…	Race

Abbreviations: ASA, American Society of Anesthesiologists; CMS, Centers for Medicare and Medicaid Services; EHR, electronic health record; HCA, HCA Healthcare.

^aData obtained from diagnostic or procedural claims codes.

^bData obtained from the National Healthcare Safety Network.