Table 3.

Relative risk ratios (and 95% confidence intervals) from multinomial logistic regression analyses assessing associations between predictors and cluster assignment

	Cluster 1		Cluster 2		Cluster 3
	Enjoyment		Health benefit		Constrained
Predictors	RRR*	95% CI	RRR*	95% CI
Female gender	0.88	0.26 to 2.96	1.69	0.62 to 4.59	Reference
Any comorbidity	0.57	0.19 to 1.69	0.54	0.22 to 1.36
Self-Efficacy for Exercise Scale score†	1.00	0.91 to 1.06	2.10‡	1.16 to 3.87
PROMIS pain interference T score†	0.53‡	0.34 to 0.86	0.70	0.47 to 1.05
Radiographic KOA (KL grade II or higher)	0.30‡	0.10 to 0.96	1.00	0.35 to 2.83
Age (65 or greater)	0.75	0.26 to 2.21	0.38‡	0.15 to 0.97
BMI (>= 30)	1.62	0.53 to 4.96	1.96	0.76 to 5.18

KOA=knee osteoarthritis, OR = adjusted odds ratio, 95% CI = 95% Confidence Interval, multinomial logistic regression includes all predictors in Table 3.

^*Adjusted Relative Risk Ratio (RRR) from multinomial logistic regression including all predictors in Table 3 compares each cluster to referent cluster 3.

^†The adjusted RRR was scaled to ½ SD (5 point) change in PROMIS score and a 3-point change in Self Efficacy for Exercise Scale.

^‡P<0.05