Development and psychometric validation of a self-administered questionnaire assessing the acceptance of influenza vaccination: the Vaccinees' Perception of Injection (VAPI©) questionnaire

Table 2 Principal Component Analysis after item reduction on the "UK Finalisation Population" set (N = 521)

# item and item content	Factor 1	Factor 2	Factor 3	Factor 4
5. Bothered by swelling?	0.804	0.111	0.180	0.189
7. Bothered by hardening (a bump)?	0.797	0.069	0.146	0.102
4. Bothered by redness?	0.793	0.054	0.099	0.148
6. Bothered by itching?	0.656	0.041	0.013	0.049
8. Bothered by bruising?	0.579	0.257	0.126	0.016
3. Bothered by pain in your arm?	0.556	0.258	0.309	0.178
14. Difficulties caused by local reaction(s) when picking up or carrying heavy objects?	0.118	0.869	0.221	0.027
28. Difficulties caused by pain when picking up or carrying heavy objects?	0.094	0.795	0.325	0.075
13. Difficulties caused by local reaction(s) in moving or lifting arm?	0.181	0.793	0.195	0.136
27. Difficulties caused by pain in moving or lifting arm?	0.177	0.746	0.287	0.211
26. Affected by pain when changing positions during night?	0.102	0.261	0.844	0.100
12. Affected by local reaction(s) when changing positions during night?	0.199	0.295	0.802	0.074
25. Bothered by pain when falling asleep?	0.120	0.209	0.783	0.169
11. Bothered by local reaction(s) when falling asleep?	0.207	0.222	0.740	0.077
39. Acceptable pain?	0.126	0.234	0.207	0.880
38. Acceptable local reaction(s)?	0.305	0.074	0.107	0.869

ISSN: 1477-7525