Table 3. Results from Logistic Regression Models to Evaluate Associations of Each Instability Variable with Odds of a Poor Basic Function Outcome and Poor Advanced Function Outcome.

The table shows the association between each instability variable at baseline and poor basic function outcome (dependent variable) and poor advanced function outcome (dependent variable), as odds ratios (ORs) and associated 95% confidence intervals (CIs) unadjusted and then adjusted for age, gender, BMI, knee pain severity, function self-efficacy, depressive symptoms, disease severity (K/L, worse of 2 knees), and knee extensor strength (of the knee with worse buckling confidence). 95% CIs that exclude 1 are statistically significant.

	Poor basic function outcome 101/212 persons (47.6%)		Poor advanced function outcome 98/212 persons (46.2%)
Instability variable (baseline)	Unadjusted OR (95% CI)	Adjusted OR (95% CI)	Unadjusted OR (95% CI)	Adjusted OR (95% CI)
Buckling, past 3 months (yes/no)	1.66 (0.94, 2.93)	1.18 (0.59, 2.35)	2.27 (1.28, 4.03)	2.08 (1.03, 4.20)
Confidence knees will not buckle (higher better, continuous)	0.61 (0.46, 0.83)	0.74 (0.51, 1.09)	0.63 (0.47, 0.85)	0.69 (0.47, 1.02)
Overall knee confidence (higher worse, continuous)	1.52 (1.09, 2.13)	1.05 (0.65, 1.68)	1.80 (1.27, 2.56)	1.65 (1.01, 2.70)
Varus-valgus excursion during gait, per 1°	0.91 (0.81, 1.01)	0.99 (0.87, 1.12)	0.95 (0.85, 1.06)	1.01 (0.89, 1.15)
Maximum varus-valgus angular velocity during gait, per 1°/sec	1.00 (0.98, 1.02)	1.00 (0.98, 1.02)	0.99 (0.98, 1.01)	0.99 (0.97, 1.01)