TABLE 2.

Psychosocial variables in final model to predict harmful alcohol use post‐LT

#	Psychosocial variable	Coef a (±SD)
1	Patient's primary support person for peri‐ and post‐LT care has not yet been identified at time of this evaluation	16.3 ± 4.2
2	Are there any pediatric children or grandchildren (<18 years old) who live with the patient?	10.6 ± 1.4
3	Was the patient recently a home caregiver for children or elderly relatives?	10.2 ± 0.7
4	Has the patient ever abused opioid pills?	10.0 ± 7.0
5	Is the patient observant in religion and/or attend services regularly?	9.5 ± 2.5
6	If applicable, does the patient currently have a healthy/strong relationship with his/her siblings?	7.8 ± 3.0
7	Did the patient ever complete a rehabilitation program?	7.3 ± 1.5
8	During the interview, did the patient make eye contact with the writer?	6.8 ± 3.3
9	Is the writer's background in social work?	6.2 ± 4.2
10	Has the patient ever been treated with methadone for opioid addiction?	6.2 ± 2.2
11	Medicaid/Medicare (vs. Private/Other) insurance?	5.2 ± 4.9
12	Did the writer discuss potential living donors?	3.0 ± 2.5
13	Patient's primary support person for peri‐ and post‐LT is non‐spouse/significant other (vs. spouse or significant other)	0.9 ± 1.2

^a Coefficient is the Gini coefficient from XGBoost, to be interpreted as relative importance of the variable in predicting harmful alcohol use post‐LT, calculated as the mean importance with standard deviation (SD) across the fivefold internal cross‐validation of the training set. The coefficient does not have a fixed “direction” (positive or negative) in XGBoost models. The XGBoost model is a “tree” of variables rather than individual variables. Higher coefficients indicate variables that are higher in the tree. An answer (yes or no) to any of these 13 variables can infer positive risk with one combination of other variables, but negative risk with other variables, as the tree needs to be interpreted as a unique combination of all 13 variables.