Psychometric study of the Persian short-form eight-item Parkinson’s disease questionnaire (PDQ-8) to evaluate health related quality of life (HRQoL)

Table 3 Spearman correlation and Cronbach’s alpha of the items of independent PDQ-8 for item-to-scale internal consistency in Iranian Parkinson’s disease patients (n = 114)

Item	Spearman Rho	Corrected Correlation	*Cronbach's α if Item Deleted*
PDQ-8-Q1	0.688	0.457	0.710
PDQ-8-Q2	0.547	0.349	0.740
PDQ-8-Q3	0.697	0.541	0.691
PDQ-8-Q4	0.494	0.483	0.708
PDQ-8-Q5	0.462	0.401	0.720
PDQ-8-Q6	0.506	0.486	0.707
PDQ-8-Q7	0.623	0.523	0.697
PDQ-8-Q8	0.468	0.330	0.733

All internal consistency correlations are statistically significant with P < 0.001.

ISSN: 1477-7525