Table 4.

Multiple imputation analysis: age-standardised percentages of white and black people developing dementia in the UK in 2015 who were diagnosed

Ethnicity	Sex	Age group (years)	Number of people in the UKa	Estimated incidence of dementiab	Estimated number of dementia cases in the UKc	Sex- and ethnicity-specific number of people in THINd	Estimated number of dementia diagnoses in THINe	Estimated number of observed dementia diagnoses in THINf	Age-standardized percentage of dementia diagnosesg
White	Male	65–69	1,669,359	0.005	8,347	103,310	517	194	37
		70–74	1,223,303	0.009	10,643	76,998	670	305	45
		75–79	943,425	0.017	15,755	56,987	952	493	53
		80–84	654,607	0.025	16,234	39,646	983	652	67
		85–89	358,444	0.038	13,621	21,766	827	504	62
	Sum		4,849,138			298,706			53
	Female	65–69	1,768,946	0.005	8,137	107,784	496	172	34
		70–74	1,348,258	0.006	8,629	83,435	534	347	64
		75–79	1,113,079	0.016	17,921	66,624	1,073	631	59
		80–84	872,250	0.040	34,541	51,886	2,055	915	45
		85–89	589,318	0.055	32,589	34,816	1,925	992	53
	Sum		5,691,851			344,545			51
Black (incidence ratio 1.63)	Male	65–69	21,021	0.008	171	844	7	2	30
		70–74	21,177	0.014	300	599	8	5	82
		75–79	14,549	0.027	396	572	16	5	28
		80–84	7,223	0.040	292	297	12	5	41
		85–89	2,226	0.062	138	164	10	6	29
	Sum		66,197			2,476			42
	Female	65–69	22,275	0.007	167	1,081	8	5	50
		70–74	23,340	0.010	243	846	9	4	50
		75–79	17,165	0.026	450	717	19	13	68
		80–84	9,625	0.065	621	438	28	8	26
		85–89	3,661	0.090	330	187	17	10	52
	Sum		76,066			3,269			49

Notes: Incidence of dementia in the white ethnic group obtained from Matthews et al;² incidence in the black ethnic group obtained by multiplying those in the white ethnic group by 1.63;³⁴ results obtained following multiple imputation of missing values in The Health Improvement Network (THIN) sample. Cell values displayed as frequency in columns a,c–f; proportion in column b; and percentage in column g. Cell calculations: c=a×b, e=d×b, g=(f/e)×(a/∑_a)/(d/∑_d)×100.