Translation and validation of a Swedish version of the Visual Vertigo Analogue Scale

Figures & data

Table 1. Descriptive stats (median (quartile 1 : quartile 3) from each item and questionnaire (n = 21).

	VVAS 1	VVAS 2	Wilcox. Sign-rank test (sig.)	Test-retest Correlation (Spearman)
Item 1	6.2 (4.8: 6.9)	6.2 (4.1: 6.8)	z = 1.356 (n.s.)	0.788**
Item 2	6.6 (4.0: 7.8)	7.4 (5.1: 8.3)	z = 0.713 (n.s.)	0.722**
Item 3	6.4 (3.5: 8.1)	5.6 (4.2: 8.4)	z = 0.299 (n.s.)	0.826**
Item 4	6.4 (4.3: 7.6)	5.8 (4.2: 7.4)	z = 0.187 (n.s.)	0.797**
Item 5	6.9 (5.5: 7.9)	6.8 (5.0: 7.8)	z = 0.896 (n.s.)	0.751**
Item 6	4.2 (2.8: 6.3)	4.9 (3.5: 6.5)	z = 0.608 (n.s.)	0.789**
Item 7	7.7 (6.0: 9.1)	7.9 (5.9: 8.7)	z = 0.299 (n.s.)	0.804**
Item 8	6.0 (4.6: 8.5)	5.5 (3.2: 7.8)	z = 0.434 (n.s.)	0.739**
Item 9	8.5 (7.3: 9.0)	8.3 (6.3: 9.1)	z = 0.747 (n.s.)	0.777**
Median score per item	6.4 (6.2: 6.9)	6.2 (5.6: 7.4)

The Median total score was 54.4 (46.7: 66.0) for VVAS 1 and 50.9 (48.1: 70.6) for VVAS 2. No significant differences were noted while a high test-retest correlation was observed. ** = p < .01.

Table 2. Inter-item internal consistency of the VVAS-S.

	Item 1	Item 2	Item 3	Item 4	Item 5	Item 6	Item 7	Item 8	Item 9
Item 1	1	0.543	0.511	0.242	0.742	0.417	0.451	0.436	0.458
Item 2		1	0.433	0.305	0.185	0.446	0.151	0.130	0.380
Item 3			1	0.575	0.604	0.632	0.121	0.651	0.412
Item 4				1	0.357	0.603	0.106	0.278	0.271
Item 5					1	0.428	0.373	0.426	0.478
Item 6						1	0.173	0.392	0.168
Item 7							1	0.169	0.507
Item 8								1	0.088
Item 9									1

Internal consistency between items were evaluated through an inter-item internal consistency matrix, where the ideal range is deemed to be between 0.2 and 0.4 to be neither unfitting nor superfluous.

Table 3. The internal consistency of the Swedish VVAS.

	CI-TC	α if item deleted
Item 1	0.715	0.813
Item 2	0.461	0.840
Item 3	0.771	0.799
Item 4	0.520	0.830
Item 5	0.657	0.816
Item 6	0.636	0.817
Item 7	0.334	0.847
Item 8	0.485	0.835
Item 9	0.492	0.834

CI-TC Corrected Item-Total Correlation; α: Cronbach’s alpha.

Corrected Item-Total Correlation (CI-TC) was calculated for each item. A value of <0.3 can be regarded as grounds for removal from a questionnaire, as it indicates that the item may not be associated with the other statements. In addition, the Cronbach’s alpha was recalculated for the removal of each item. The Cronbach’s alpha for the intact questionnaire was 0.843.

Data availability statement

Data is available upon reasonable request from the authors.