TABLE 2.

Predicting pain chronicity: Optimized input variable sets and performance metrics

Model	Optimized variable set	Variable description	Accuracy (95% CI)	AUC (95% CI)	Sensitivity (95% CI)	Specificity (95% CI)
Artificial neural network (ANN)	V00PCTALCH	Block Brief 2000: daily percent of calories from alcoholic beverages (kcal) (calc)	Testing: 78% (77%, 80%) Training: 84% (83%, 84%)	0.81 (0.79, 0.82)	81% (79%, 83%)	73% (70%, 76%)
	V00SF8	SF‐12: how much did pain interfere with normal work (include work outside home and housework), past 4 weeks
	V00SF3	SF‐12: how much health limit climbing several flights of stairs
	V00NARCOT	Q50e.Used strong prescription pain medications (e.g., narcotics) for joint pain or arthritis more than half the days of the month, past 30 days
Support vector machine (SVM)	V00PCTALCH	Block Brief 2000: daily percent of calories from alcoholic beverages (kcal) (calc)	Testing: 78% (77%, 79%) Training: 94% (94%, 94%)	0.83 (0.81, 0.84)	82% (80%, 84%)	72% (69%, 74%)
	V00BONEFX	Doctor ever said you broke or fractured bone after age 45
	V00HSPSS	SF‐12: physical summary scale for the MOS 12‐item short‐form health survey (SF‐12) v2 (calc)
	V00RXNSAID	MIF: Rx NSAID use indicator (calc)
	V00SF8	SF‐12: how much did pain interfere with normal work (include work outside home and housework), past 4 weeks
	V00SF3	SF‐12: how much health limit climbing several flights of stairs
	V00NARCOT	Q50e.Used strong prescription pain medications (e.g., narcotics) for joint pain or arthritis more than half the days of the month, past 30 days
Random forest (RF)	V00PCTALCH	Block Brief 2000: daily percent of calories from alcoholic beverages (kcal) (calc)	Testing: 76% (75%, 78%) Training: 76% (75%, 77%)	0.83 (0.81, 0.84)	85% (83%, 86%)	70% (67%, 73%)
	V00SF8	SF‐12: how much did pain interfere with normal work (include work outside home and housework), past 4 weeks
	V00SF3	SF‐12: how much health limit climbing several flights of stairs
	V00NARCOT	Q50e.Used strong prescription pain medications (e.g., narcotics) for joint pain or arthritis more than half the days of the month, past 30 days
Logistic regression (LR)	V00BONEFX	Doctor ever said you broke or fractured bone after age 45	Testing: 76% (75%, 78%) Training: 77% (76%, 77%)	0.80 (0.78, 0.82)	83% (80%, 85%)	66% (63%, 69%)
	V00SF8	SF‐12: how much did pain interfere with normal work (include work outside home and housework), past 4 weeks
	P01BPTOT	Total days in bed and/or limited activity due to back pain, past 30 days (calc)

Abbreviation: AUC, area under the receiver operator characteristic curve.