Table 2. Demographic characteristics of the observed ALS cases in the data sources.

	CARE	ALS	University	Clinical	Clinics/	NPD
		Registry	Clinics	Centers	Hospital	and MCC
Number of cases	539.9	438	256	122	130	4
Estimated completeness (%)		81%	47%	23%	24%	1%
Age (years): Mean		64.2	61.5	64.6	67.6	66.3
(SD)		(12.1)	(11.3)	(12.4)	(11.1)	(19.4)
Gender ratio (men:women)		1.1	1.4	0.8	0.8	1

Abbreviations:

estimated total number; CARE capture-recapture methods; NPD and MCC: private neurological practice doctors and medical care centers.