Evaluating the completeness of the national ALS registry, United States

Figures & data

Table 1. Comparison of demographic characteristics for matched and unmatched cases.

Unmatched			Matched			Chi-square
Age At DX	Number	%	Age at DX	Number	%	43.93, p < 0.00001
<65	1321	64.5%	<65	1500	55.1%
≥65	705	34.4%	≥65	1195	43.9%
Unknown	21	1.0%	Unknown	25	0.9%
Total	2047		Total	2720
Race			Race			34.01, p < 0.00001
White	1409	68.8%	White	2071	76.1%
Black	213	10.4%	Black	237	8.7%
Asian	98	4.8%	Asian	84	3.1%
Other	9	0.4%	Other	10	0.4%
Unknown	318	15.5%	Unknown	318	11.7%
Total	2047		Total	2720
Sex			Sex			1.78, p = 0.18
Male	1148	56.1%	Male	1578	58.0%
Female	899	43.9%	Female	1142	42.0%
Total	2047		Total	2720
Hispanic			Hispanic			37.60, p < 0.00001
Yes	300	14.7%	Yes	270	9.9%
No	1454	71.0%	No	2136	78.5%
Unknown	293	14.3%	Unknown	314	11.5%
Total	2047		Total	2720
Area*			Area*			84.05, p < 0.00001
TX, FL, AT	997	48.7%	TX, FL, AT	1606	59.0%
LA, SF, LV	544	26.6%	LA, SF, LV	440	16.2%
NJ, BA, PH, DT, CI	506	24.7%	NJ, BA, PH, DT, CI	674	24.8%
Total	2047		Total	2720

*TX: Texas; FL: Florida; AT: Atlanta; LA: Los Angeles; SF: San Francisco; LV: Las Vegas; NJ: New Jersey; BA: Baltimore; PH: Philadelphia; DT: Detroit; CI: Chicago.

Table 2. Comparison of ALS diagnosis criteria and insurance for matched and unmatched cases.

Unmatched			Matched			Chi-square
El Escorial criteria						65.79, p < 0.00001
Definite	961	46.9%	Definite	1460	53.7%
Probable	430	21.0%	Probable	603	22.2%
Probable + Lab	165	8.1%	Probable + Lab	254	9.3%
Possible	358	17.5%	Possible	290	10.7%
Unclassified	133	6.5%	Unclassified	113	4.2%
Total	2047		Total	2720
Combined El Escorial criteria						47.63, p < 0.00001
Definite + Probable	1556	76.0%	Definite + Probable	2317	85.2%
Possible + Unclassified	491	24.0%	Possible + Unclassified	403	14.8%
Total	2047		Total	2720
Medicare						359.82, p < 0.00001
Yes	788	38.5%	Yes	1799	66.1%
No	1236	60.4%	No	902	33.2%
Unknown	23	1.1%	Unknown	19	0.7%
Total	2047		Total	2720
Veterans Administration (VA)						3.54, p = 0.17
Yes	116	5.7%	Yes	175	6.4%
No	1908	93.2%	No	2526	92.9%
Unknown	23	1.1%	Unknown	19	0.7%
Total	2047		Total	2720
Private Insurance						3.14, p = 0.21
Yes	898	43.9%	Yes	1232	45.3%
No	1126	55.0%	No	1469	54.0%
Unknown	23	1.1%	Unknown	19	0.7%
Total	2047		Total	2720

Table 3. Regression on significant univariate variables, age group and the two interactions.

			95% Confidence Limits
Effect	DF	Parameter Estimates	Lower	Upper	Wald Chi-Square	p Value
Intercept		0.0353	−0.0776	0.1482
Medicare	2				323.92	<0.0001
Yes		1.1173	0.9954	1.2391
Unknown		0.2940	−0.3292	0.9172
State Combined	2				65.13	<0.0001
LA, SF, LV		−0.6398	−0.7982	−0.4813
NJ, BA, PH, DT, CI		−0.2967	−0.4448	−0.1486
Ethnicity	2				12.40	<0.0020
Hispanic		−0.3590	−0.5614	−0.1566
Unknown		−0.1509	−0.3498	0.0481
Race	4				12.10	0.0167
African American		−0.2339	−0.4422	−0.0256
Asian		−0.2692	−0.5884	0.0501
Other		−0.4302	−1.3832	0.5228
Unknown		−0.2486	−0.4511	−0.0462

Goodness of Fit p-value = 0.082.