Table 2. Reliability criteria.

Type of reliability	Criteria	Preponderance of evidence
Internal consistency Cronbach’s alpha (α)	Adequate	0.70-0.79
	Good	0.80-0.89
		Excellent	≥0.90
Inter-rater reliability kappa (κ) Intraclass correlation (ICC) Pearson correlation (p)	Adequate	κ value 0.60-0.74 ICC or p-value 0.70-0.79
	Good	κ values 0.75-0.84 ICC or p-value 0.80-0.79
	Excellent	κ value >0.85 ICC or p-value >0.90
Test-Retest reliability	Adequate	0.70 over a period of several days to several weeks
	Good	0.70 over a period of several months
	Excellent	0.70 over a period of 1 year or longer