Rate of first recorded diagnosis of autism and other pervasive developmental disorders in United Kingdom general practice, 1988 to 2001

Table 3 Crude rates of first diagnosis (per 10 000 person-years) and age standardised incidence ratios for autism and other PDDs by year of diagnosis

year	Total cases	Cases with 'other PDD' diagnosis	% cases with 'other PDD' diagnosis	incidence other PDDs	incidence autism	SIR other PDDs	SIR autism
1988	1	0	0	0	0.11	0	10
1989	6	0	0	0	0.23	0	23
1990	21	0	0	0	0.33	0	35
1991	45	0	0	0	0.40	0	44
1992	45	0	0	0	0.34	0	39
1993	69	2	3	0.01	0.49	6	58
1994	77	2	3	0.01	0.52	6	64
1995	108	3	3	0.02	0.71	9	91
1996	102	8	8	0.06	0.68	27	92
1997	133	18	14	0.14	0.90	67	128
1998	192	51	27	0.42	1.15	204	173
1999	231	87	38	0.78	1.28	369	200
2000	211	82	39	0.88	1.38	435	225
2001	169	60	36	1.06	1.92	495	319

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