Table 2. Expected and observed number of comorbid cases for the three cutoff criteria.

Deficit	Cutoff [sd]	Comorbidity rate expected %	Cases expected [E]	Cases observed [O]	Ratio O/E
RD+SD	1	2.59	42	118	2.8
	1.25	1.30	21	69	3.3
	1.5	0.63	10	47	4.7
RD+AD	1	2.01	33	87	2.6
	1.25	0.77	13	41	3.2
	1.5	0.35	6	25	4.2
SD+AD	1	2.15	35	102	2.9
	1.25	1.00	16	62	3.9
	1.5	0.44	7	34	4.9