. 2020 Aug 27;10(11):e01806. doi: 10.1002/brb3.1806

Table 2.

Mean CDT scores (mean, standard deviation) and percentile ranks for the CDT3, CDT10, CDT18 stratified for age and years of education (N = 418)

Age	Education	N	Mean (SD)	Mean −SD	Mean −1.5 SD	Mean −2 SD	Percentiles
Age	Education	N	Mean (SD)	Mean −SD	Mean −1.5 SD	Mean −2 SD	1	2	5	10	15	25	50
CDT3 ^a
35–64	≤9	108	2.68 (0.54)	2.14	1.86	1.59	1.0	1.0	2.0	2.0	2.0	2.0	3.0
	10–12	77	2.75 (0.52)	2.23	1.97	1.72	1.0	1.0	1.9	2.0	2.0	3.0	3.0
	≥13	36	2.83 (0.38)	2.45	2.26	2.07	2.0	2.0	2.0	2.0	2.0	3.0	3.0
65–84	≤9	121	2.52 (0.60)	1.91	1.61	1.31	1.0	1.0	1.0	2.0	2.0	2.0	3.0
	10–12	58	2.71 (0.56)	2.15	1.87	1.59	1.0	1.0	1.0	2.0	2.0	2.8	3.0
	≥13	18	2.67 (0.49)	2.19	1.94	1.70	2.0	2.0	2.0	2.0	2.0	2.0	3.0
CDT10 ^b
35–64	≤9	108	8.38 (1.62)	6.76	5.96	5.15	3.1	4.0	5.0	6.0	6.4	8.0	9.0
	10–12	77	8.75 (1.40)	7.35	6.65	5.96	5.0	5.0	5.0	6.8	7.0	8.0	9.0
	≥13	36	9.17 (1.11)	8.06	7.51	6.95	6.0	6.0	6.0	7.7	8.0	9.0	9.5
65–84	≤9	121	7.99 (1.87)	6.12	5.19	4.25	2.2	3.0	4.1	5.0	6.0	7.0	8.0
	10–12	58	8.67 (1.46)	7.21	6.49	5.76	3.0	3.4	5.0	6.9	7.9	8.0	9.0
	≥13	18	8.67 (1.33)	7.34	6.68	6.01	6.0	6.0	6.0	6.9	7.0	7.8	9.0
CDT18 ^c
35–64	≤9	108	14.70 (2.22)	12.48	11.37	10.26	8.0	8.2	10.0	11.0	13.0	13.3	15.0
	10–12	77	15.68 (1.70)	13.98	13.12	12.27	11.0	11.6	12.0	13.0	13.7	15.0	16.0
	≥13	36	16.11 (1.49)	14.62	13.88	13.13	12.0	12.0	12.9	14.0	14.5	15.0	16.0
65–84	≤9	121	14.15 (2.65)	11.50	10.17	8.84	3.1	7.0	8.1	11.0	12.0	13.0	15.0
	10–12	58	15.34 (1.86)	13.48	12.55	11.62	10.0	10.2	11.0	13.0	13.0	14.0	16.0
	≥13	18	15.22 (1.99)	13.23	12.24	11.25	11.0	11.0	11.0	11.9	12.9	13.8	16.0

^{^a}

Clock‐drawing test scoring system derived from the Montreal Cognitive Assessment.

^{^b}

Clock‐drawing test scoring system of Rouleau et al. (1992).

^{^c}

Clock‐drawing test scoring system of Babins et al. (2008).