Psychometric evaluation of the near activity visual questionnaire presbyopia (NAVQ-P) and additional patient-reported outcome items

Journal of Patient-Reported Outcomes

Table 7 Known-groups validity of NAVQ-P Total Score and NVCI and NVS scores at Month 2 using PGI-S and DCNVA-defined severity groups

	Cross-sectional analysis population (N = 227)
Target Score / Known-groups	n	Mean (SD)	Between-Groups Effect Size	Pair-wise comparison p-value
NAVQ-P Total Score
PGI-S*
None/Mild (reference)	67	13.16 (8.25)
Moderate	80	23.85 (8.25)	1.30	<0.001
Severe/Very severe	76	35.68 (7.04)	2.95	<0.001
DCNVA
DCNVA < 0.6 logMAR (better visual acuity)	207	24.48 (11.91)
DCNVA > = 0.6logMAR (worse visual acuity)	15	26.47 (12.80)	0.17	0.536
NVCI
PGI-S*
None/Mild (reference)	69	1.59 (1.02)
Moderate	81	2.84 (0.83)	1.35	< 0.001
Severe/Very severe	77	3.68 (0.68)	2.43	< 0.001
DCNVA
DCNVA < 0.6 logMAR (better visual acuity)	210	2.75 (1.18)		0.681
DCNVA > = 0.6 logMAR (worse visual acuity)	16	2.63 (1.36)	-0.11
NVS
PGI-S*
None/Mild (reference)	69	2.20 (0.88)
Moderate	81	1.23 (0.69)	-1.23	< 0.001
Severe/Very severe	77	0.51 (0.79)	-2.03	< 0.001
DCNVA
DCNVA < 0.6 logMAR (better visual acuity)	210	1.32 (1.05)		0.099
DCNVA > = 0.6 logMAR (worse visual acuity)	16	0.88 (0.72)	-0.43	0.099

*For the PGI-S, participants responding with ‘None’ or ‘Mild’ were grouped together as were participants responding with ‘Severe’ or ‘Very severe’ in order to ensure adequate sample size in each PGI-S group. The between groups effect size is using Hedge’s g compared to the reference group (ref). Hedge’s g is calculated as the difference in means ((comparison group) - (reference group)) divided by the pooled standard deviation. P-value based on a two-sample t-test testing mean score differences between groups. NAVQ-P total scores range from 0–42, with higher scores indicating greater symptom severity. NVCI and NVS scores range from − 4 to + 4. A higher score on the NVS indicates greater satisfaction with near vision, without a near vision correction aid. A higher score on the NVCI indicates greater dependency on a near vision correction aid