Update on the psychometric properties and minimal important difference (MID) thresholds of the FACT-M questionnaire for use in treatment-naïve and previously treated patients with metastatic Merkel cell carcinoma

Table 3 Pearson correlation coefficients between FACT-M and EQ-5D scores at baseline (n = 172)*

Score at baseline	EQ-5D mobility	EQ-5D self-care	EQ-5D usual activity	EQ-5D pain/ discomfort	EQ-5D anxiety/ depression	EQ VAS	EQ-5D Index
FACT-G subscales
Physical well-being	− 0.43**	− 0.39	− 0.64	− 0.68	− 0.43	0.59	0.65
Social/Family well-being	−0.21	− 0.14	− 0.19	− 0.12	− 0.24	0.22	0.22
Emotional well-being	− 0.31	− 0.27	− 0.45	−0.41	− 0.59	0.52	0.48
Functional well-being	−0.46	−0.33	− 0.63	−0.51	− 0.52	0.56	0.61
Melanoma-specific subscales
Melanoma subscale*	−0.49	−0.41	− 0.70	−0.65	− 0.49	0.63	0.68
Melanoma surgery scale	−0.38	−0.42	− 0.53	−0.45	− 0.26	0.45	0.50
Summary scales
FACT-M TOI	−0.50	−0.41	− 0.72	−0.66	− 0.53	0.65	0.71
FACT-G Total score	−0.45	−0.35	− 0.60	−0.54	− 0.55	0.59	0.62
FACT-M Total score	−0.49	−0.39	− 0.67	−0.60	− 0.56	0.64	0.67
MCC-specific scores
Physical function (PF)	−0.56	−0.40	− 0.73	−0.59	− 0.47	0.57	0.68
Psychological impact (PI)	−0.30	−0.26	− 0.45	−0.43	− 0.58	0.50	0.48
MCC summary score	−0.49	−0.38	− 0.67	−0.57	− 0.57	0.60	0.66

* Negative correlations are due to the different scoring of the two instruments, with high EQ-5D item scores reflecting greater health/function problems, whereas for scores from the FACT-M, higher scores indicate better well-being or health status
** Grey shadings indicate correlations between EQ-5D item / index / EQ VAS scores expected to correlate highest with FACT-M subscale / summary / MCC-specific scores
TOI = Trial Outcome Index; MCC = Merkel cell carcinoma; *n = 171 for Melanoma subscale

ISSN: 1477-7525