Table 4.

Reliability of the Prescription Quality Index (PQI) scores in patients with chronic diseases

Criterion	Correlation with the PQI total score	Corrected item total correlation	Cronbach's α if item deleted
1. Indication	0.6b**	0.5	0.5
2. Dosage	0.6b**	0.3	0.6
3. Effectiveness	0.4b**	0.4	0.6
4. Evidence-based	0.3b**	0.3	0.6
5. Correct directions	0.3b**	0.1	0.6
6. Practical directions	0.4b**	0.2	0.6
7. Drug–drug interactions	0.4b**	0.1	0.6
8. Drug–disease/condition interactions	0.4b**	0.4	0.6
9. Adverse drug reaction	0.4b**	0.3	0.6
10. Unnecessary duplication	0.1b	0.0	0.6
11. Duration of therapy	0.4b**	0.4	0.6
12. Cost	0.3b**	0.1	0.6
13. Generic prescribing	0.4a**	0.2	0.6
14. Formulary or essential drug list	0.1b	0.0	0.6
15. Compliance	0.3b**	0.2	0.6
16. Medication's name	0.3b**	0.2	0.6
17. Legibility	0.1b	0.1	0.6
18. Prescriber's information	0.3b**	0.0	0.6
19. Patient's information	0.2b	0.0	0.6
20. Diagnosis	0.4a**	0.2	0.6
21. Requirement for drug therapy	0.2b*	0.2	0.6
22. Patient's improvement	0.2b*	0.1	0.6

^*Correlation significant at 0.01 level (two-tailed).

^**Correlation significant at 0.05 level (two-tailed).

^aPearson correlation.

^bSpearman's ρ.