Table 4.

Validity indices for performance-based clinical balance tests among unilateral lower limb prosthesis users for two faller classifications

≥ 1 falls (any falls)
Test	AUC (95% CI)	Cutoff Score	Sensitivity (95% CI)	Specificity (95% CI)	LR+ (95% CI)	LR− (95% CI)
NBWT (/1.00)	.81 (.62–.91)	≤ 0.43	73% (53%–90%)	76% (54%–96%)	3.0 (1.5–6.9)	.36 (.19–.77)
TUG (sec)	.71 (.54–.88)	≥ 8.17	83% (68%–98%)	68% (46%–92%)	2.6 (1.3–5.6)	.24 (.13–.56)
FSST (sec)	.70 (.53–.86)	≥ 8.49	74% (58%–92%)	68% (46%–92%)	2.4 (1.1–5.2)	.36 (.17–.78)
BBS (/56)	.66 (.47–.83)	≤ 50.5	67% (48%–86%)	62% (39%–86%)	1.8 (.89–3.6)	.53 (.27–1.1)
ABC (/100)	.65 (.47–.82)	≤ 80.2	50% (30%–70%)	74% (54%–96%)	1.9 (.78–5.1)	.67 (.41–1.1)
Model 1	.84 (.71–.96)	N/A	80% (64%−96%)	73% (51%–96%)	3.0 (1.3–7.1)	.27 (.12–.63)
≥ 2 falls (multiple falls)
Test	AUC (95% CI)	Cutoff Score	Sensitivity (95% CI)	Specificity (95% CI)	LR+ (95% CI)	LR− (95% CI)
NBWT (/1.00)	.89 (.78–1.0)	≤ 0.43	88% (73%–100%)	79% (65%–92%)	4.2 (1.7–6.9)	.16 (.042–.60)
TUG (sec)	.88 (.78–.98)	≥ 9.25	82% (64%–100%)	83% (67%–98%)	4.7 (1.9–11.9)	.21 (.075–.61)
FSST (sec)	.88 (.76–.99)	≥ 8.71	94% (83%–100%)	74% (60%–92%)	3.6 (1.8–7.3)	.08 (.012–.54)
BBS (/56)	.81 (.66–.92)	≤ 50.5	88% (73%–100%)	70% (51%–88%)	2.9 (1.5–5.5)	.17 (.045–.64)
ABC (/100)	.71 (.54–.87)	≤ 80.2	65% (42%–87%)	78% (61%–95%)	3.0 (1.3–7.0)	.45 (.23–.89)
Model 2	.90 (.79–1.0)	N/A	76% (56%–97%)	83% (67%–98%)	4.4 (1.7–11.3)	.28 (.12–.68)

ABC: Activities-specific Balance Confidence Scale; AUC: Area Under the Curve; BBS: Berg Balance Scale; CI: Confidence Interval; FSST: Four Square Step test; LR-: negative likelihood ratio; LR+: positive likelihood ratio; NBWT: Narrowing Beam Walking Test; TuG: Timed Up and Go.

Model 1: NBWT; FSST; PLUS-M; amputation level

Model 2: NBWT; TUG; PLUS-M; K-level; amputation etiology