Table 2.

Factor analysis, reliability, and validity of measures for blood donors with caller tunes. Multimedia Appendix 1 outlines all items and their corresponding statements.

Item		Internal reliability			Convergent validity
		Cronbach alpha	Item-total correlation	Factor loading	Composite reliability	Average variance extracted
Perceived ease of use (PEU)		.893			0.92	0.61
	PEU1		0.63	0.72
	PEU2		0.74	0.82
	PEU3		0.74	0.82
	PEU4		0.67	0.76
	PEU5		0.70	0.79
	PEU6		0.74	0.82
	PEU7		0.64	0.74
Perceived usefulness for blood donation (PUBD)		.862			0.92	0.77
	PUBD1		0.75	0.89
	PUBD2		0.74	0.89
	PUBD3		0.74	0.88
Attitudes to using caller tunes for blood donation (BDA)		.851			0.90	0.70
	BDA1		0.74	0.87
	BDA2		0.65	0.80
	BDA3		0.77	0.89
	BDA4		0.63	0.79