Psychometric validation of the visual function questionnaire-25 in patients with diabetic macular edema

Table 5 Responsiveness from baseline to week 54

	*Group*: Patients with a > = 5 letter improvement on the ETDRS in their study eye between baseline and week 54
	VFQ-25 Change Score					Guyatt’s Responsiveness
VFQ-25 Domain	n	Mean	P value from one-sample t-test	Effect Size*	SRM ^†	n	Statistic ^‡
1. General Health	93	3.23	.14	0.15	0.15	30	0.12
2. General Vision	93	10.32	<.001	0.55	0.56	30	0.57
3. Ocular Pain	93	2.96	.16	0.13	0.15	30	0.14
4. Near Activities	93	5.69	.011	0.23	0.27	30	0.29
5. Distance Activities	93	3.67	.12	0.15	0.16	30	0.21
6. Social Functioning	93	0.54	.75	0.02	0.03	30	0.02
7. Mental Health	93	4.64	.024	0.17	0.24	30	0.21
8. Role Difficulties	93	11.29	<.001	0.41	0.38	30	0.49
9. Dependency	93	2.78	.25	0.09	0.12	30	0.10
10. Driving	56	5.73	.018	0.16	0.33	17	0.25
11. Colour Vision	91	1.92	.35	0.09	0.10	30	0.09
12. Peripheral Vision	93	4.30	.070	0.17	0.19	30	0.19
VFQ-25 Composite	93	4.90	<.001	0.26	0.43	30	0.39

* Effect size: the mean change score divided by the standard deviation of the baseline score.
† Standardized response mean: the mean change score divided by the standard deviation of the change score.
‡ Guyatt's responsiveness statistic: the mean change score divided by the standard deviation of change in subjects who remained stable. Stable groups are defined as an increase or a decrease of up to 1 letter.

ISSN: 1477-7525