Table 2.

Psychometric properties (content validity, item fit, unidimensionality, person separation reliability, and 1-month test-retest reliability) of the gamified medication literacy tool in a validation sample (phase 1, n=81, grades 4 and 6, Nanjing, China, 2025).

Domain	Content validity (I-CVIa); item fit (mean infit MNSQb)	Unidimensionalityc (residual eigenvalue/ratio)	Person separation reliabilityd	Test-retest reliability, ICCe (95% CI)
Knowledge	1.00; 1.01	2.25/0.40	0.69	0.76 (0.64-0.84)
Attitude	1.00; 1.07	2.14/0.34	0.72	0.92 (0.88-0.95)
Perceived behavioral control	1.00; 1.04	2.19/0.34	0.71	0.86 (0.79-0.91)
Behavioral Intention	1.00; 1.04	2.21/0.38	0.74	0.86 (0.79-0.91)

^aI-CVI: item-level content validity index (unanimous agreement among 5 experts per panel; I-CVI=1; scale-level content validity index/average [S-CVI/Ave]=1.00).

^bMNSQ: mean-square statistic (item fit was considered acceptable if infit MNSQ was between 0.5 and 1.5).

^cUnidimensionality criteria: residual eigenvalue (first residual component eigenvalue) <3.0 and ratio of the second to first eigenvalue <0.5.

^dPerson separation reliability ≥0.70.

^eICC: intraclass correlation coefficient. ICC(3,1) was calculated over a 1-month interval using a 2-way mixed-effects model with absolute agreement; ICC≥0.70 was considered acceptable).