Table 1.

K-Means Cluster Analysis: patients were divided into three groups according to WHO-DAS II and IWQoL-Lite scores.

	Cluster			F
	A	B	C
WHO-DAS II	8.6 (6.1–11.1)	22.7 (19.6–25.9)	47 (42.3–51.8)	110.6*
IWQoL-Lite	59 (55–62)	87 (84–90)	110 (104–117)	161.1*

Note. For each group, cluster centroids and 95% confidence interval are reported; *P < .001. Bonferroni post hoc test was significant for each pair, both for WHO-DAS II and IWQoL-Lite total scores. Cluster A: 43 cases, lower disability, and HRQoL reduction; Cluster B: 50 cases, intermediate disability, and HRQoL reduction; Cluster C: 24 cases, higher disability, and HRQoL reduction.