Validation of the Italian translation of the perceived stigma scale and resilience assessment in inflammatory bowel disease patients

Table 1 Thresholds defining acceptable psychometric properties according to the International Quality of Life Assessment project

	Definition	Threshold
Data quality
Missing items	Unanswered items	< 5%-10%
	Incomplete scales (< 50% of items answered)	< 5%-10%
Floor and ceiling effect	Extreme scores (either on the lower- or higher-end)	< 10%
Scaling assumption
Internal consistency
Item	Correlation among items of the same scale (Pearson correlation ≥ 0.4)	> 90%
Reliability	Overall consistency of the scale (Cronbach’s alpha coefficient)	> 0.7
Discriminant validity	Items whose Pearson correlation with other scales is higher than with their scale	0%
Test-retest evaluation	Correlation between the results scales filled in twice by the same patients at defined time points (Pearson correlation)	> 0.7