Table 5.

Correlation between items in C-PHQ-9 and each item and total score (r)

Items	Q1	Q2	Q3	Q4	Q5	Q6	Q7	Q8	Q9
Q1	1
Q2	0.608*	1
Q3	0.749*	0.650*	1
Q4	0.661*	0.788*	0.561*	1
Q5	0.702*	0.606*	0.589*	0.634*	1
Q6	0.625*	0.508*	0.591*	0.567*	0.680*	1
Q7	0.490*	0.390*	0.431*	0.509*	0.589*	0.803*	1
Q8	0.501*	0.376*	0.438*	0.527*	0.573*	0.804*	0.858*	1
Q9	0.499*	0.376*	0.436*	0.543*	0.589*	0.804*	0.868*	0.933*	1
Total score	0.840*	0.839*	0.839*	0.854*	0.761*	0.683*	0.573*	0.575*	0.540*

Q1 refers to the first score, Q2 refers to the second score, and so on.

*P<0.01 (two-sided test).

C-PHQ-9, Chinese version of the Patient Health Questionnaire-9.