Reliability and Validity of the Greek QLQ-C30 and QLQ-MY20 for Measuring Quality of Life in Patients with Multiple Myeloma

Table 5

Multivariate analyses (𝐵 coefficient ^(p-sig.)).

Dependent variable predictors	Dependent Variable
	PF	RP	BP	GH	VT	SF	RE	MH
QLQ-C30
Global health status	0.22	—	0.38^*	—	0.22	—	—	—
Physical functioning	0.83^***	0.56	—	0.23	0.34^***	—	—	—
Role functioning	—	0.36	—	—	—	0.20	0.49^**	—
Emotional functioning	—	—	—	—	—	0.24	—	0.48^***
Cognitive functioning	—	—	—	—	—	—	0.47	—
Social functioning	—	—	—	—	—	0.45^**	—	—
Fatigue	—	—	—	−0.20	−0.20^**	—	—	—
Nausea and vomiting	—	—	—	—	—	—	—	—
Pain	—	—	−0.67^***	—	—	—	—	—
Dyspnoea	−0.13	—	—	—	—	—	—	—
Insomnia	—	—	—	—	—	—	—	−0.11
Appetite loss	—	—	—	—	—	—	—	−0.19^*
Constipation	—	—	—	—	—	—	—	—
Diarrhea	—	—	—	—	−0.17	—	—	—
Financial difficulties	—	—	—	—	—	—	—	—
Constant	−13.46	−25.09	54.26	41.46	24.60	−1.00	−13.02	32.29
Adjusted 𝑅^2	0.687	0.290	0.601	0.195	0.588	0.421	0.282	0.618
QLQ-MY20
Disease symptoms	−0.40^*	—	−0.90^***	−0.28^*	—	—	—	—
Side effects of treatment	−0.68^**	—	—	—	−0.66^***	−0.47	—	−0.50^***
Body image	—	0.39^**	—	—	0.13	0.25^*	0.34^*	0.15
Future perspective	—	—	—	0.23^**	—	—	—	0.21^**
Constant	70.51	7.21	75.96	40.88	54.96	56.18	33.90	48.27
Adjusted 𝑅^2	0.324	0.101	0.330	0.205	0.390	0.205	0.069	0.453

PF: physical functioning, RP: role-physical, BP: bodily pain, GH: general health, VT: vitality, SF: social functioning, RE: role emotional, and MH: mental health.
^∗𝑃<0.05, ^∗∗𝑃<0.01, and ^∗∗∗𝑃<0.001, according to OLS regression with stepwise selection and Bonferroni adjustment for multiple testing.