Table 4.

Distribution of scores and reliability of the Spanish and Catalan patient reported experiences and outcomes of safety in primary care (PREOS-PC) scales.

	N		Mean (SD)		Respondents with the lowest possible score (%)		Respondents with the highest possible score (%)		Internal consistency				Test-retest reliabilityc	PCC mean scores
									Cronbach’s αa, mean		Inter-item correlationb, standardised mean		ICCd (95%CI)	Precision (standard error)		Between-practices reliability		N of responses needed for 0.7 reliability
Scales	Spa	Cat	Spa	Cat	Spa	Cat	Spa	Cat	Spa	Cat	Spa	Cat	Spa	Spa	Cat	Spa	Cat	Spa	Cat
Practice activation	3284	1005	81.20 (19.89)	81.94 (18.79)	0.03	0.50	33.80	32.04	0.705	0.667	0.374	0.334	0.832 (0.703; 0.904)ep < .001	2.603	3.749	0.731	0.644	48	30
Patient Activation	3028	936	38.91 (36.88)	34.21 (37.38)	34.91	43.48	13.74	13.03	0.854	0.865	0.745	0.762	0.402 (−0.0450; 0.662)ep = .036	5.071	7.503	0.613	0.760	76	16
Harm severity	3218	992	96.53 (12.13)	97.26 (9.88)	0.31	0.81	89.81	90.93	0.808	0.688	0.584	0.423	0.069 (−0.319; 0.382) p = .354	1.632	2.053	0.425	0.114	172f	419f
Harm burden	3237	991	96.13 (12.48)	97.39 (9.32)	0.34	0.10	88.51	90.92	0.800	0.617	0.572	0.350	0.055 (−0.329; 0.369) p = .383	1.677	1.941	0.332	0.040	258f	1275f
Overall rating of patient safety	3287	1007	84.65 (16.30)	85.70 (15.27)	0.15	0.20	34.16	64.35	N/A	N/A	N/A	N/A	0.411 (0.027; 0.648)ep = .015	2.156	3.082	0.595	0.543	88	46

Cat: Catalan; CI: confidence interval; ICC: intercluster correlation coeficient; N/A: non-applicable (single item scales); PCC: Primary Care Centres; SD: standard deviation; Spa: Spanish.

^a An α > 0.7 represents adequate internal consistency, and an α > 0.8 is considered good.

^b Inter-item correlations above 0.3 are considered adequate.

^c Based on data from 55 patients who completed the questionnaire again after two weeks.

^d Two-way random-effects intra-class correlation coefficients and 95% confidence intervals.

^e p <.05.

^fResponses needed to have sufficient cases reporting harm.