Table 2.

Prevalence of chronic disease

Disease	Intellectual disability (n= 14 751)		Controls (n= 86 221)		Prevalence ratio (95% CI)
	n	%	n	%
Epilepsya	2731	18.5	633	0.7	25.33 (23.29 to 27.57)
Severe mental illness	1266	8.6	823	1.0	9.10 (8.34 to 9.92)
Schizophrenia	995	6.8	591	0.7	9.94 (8.99 to 10.99)
Affective disorder	371	2.5	333	0.4	6.66 (5.73 to 7.73)
IHD	244	1.7	2316	2.7	0.65 (0.57 to 0.74)
Heart failure	121	0.8	324	0.4	2.26 (1.84 to 2.78)
Stroke and TIA	267	1.8	944	1.1	1.74 (1.52 to 1.98)
Atrial fibrillation	122	0.8	821	1.0	0.91 (0.75 to 1.09)
Hypertension	1583	10.7	10 416	12.1	0.93 (0.89 to 0.98)
Peripheral vascular disease	61	0.4	423	0.5	0.90 (0.69 to 1.17)
Chronic kidney disease	468	3.2	1746	2.1	1.64 (1.49 to 1.82)
Diabetes	1017	6.9	3786	4.4	1.64 (1.53 to 1.75)
Hypothyroidisma	1169	7.9	2649	3.1	2.69 (2.52 to 2.87)
Asthmaa	1208	8.2	5717	6.6	1.25 (1.18 to 1.33)
COPD	160	1.1	1184	1.4	0.84 (0.71 to 0.99)
Cancer	238	1.6	2090	2.4	0.70 (0.61 to 0.80)
Osteoporosis	246	1.7	822	1.0	1.84 (1.60 to 2.12)
Rheumatoid arthritis	73	0.5	550	0.6	0.82 (0.65 to 1.05)
Dementia	160	1.1	134	0.2	7.52 (5.95 to 9.49)
Depression	2609	17.7	15 179	17.6	1.03 (0.99 to 1.06)
Anxiety (ever)	2398	16.3	12 580	14.6	1.13 (1.09 to 1.18)
Number of QOF conditionsb
0	6320	42.8	53 856	62.5	–
1	5056	34.3	20 901	24.2	–
2	2138	14.5	7174	8.3	–
≥3	1237	8.4	4290	5.0	–

^aAlso require recent medication as per QOF definition.

^bExcludes anxiety from the above list.

COPD = chronic obstructive pulmonary disease. IHD = ischaemic heart disease. QOF = Quality and Outcomes Framework. TIA = transient ischaemic attack.