Epidemiology and surveillance of amyotrophic lateral sclerosis in two large metropolitan areas in California

Figures & data

Table I. Characteristics of ALS cases identified for San Francisco Bay Area (SFBA) and Los Angeles County (LA), 2009–2011.

Characteristic	All cases (number (%))		Incident cases (number (%))
	SFBA	LA	SFBA	LA
Total	539	545	288	330
Gender
Males	320 (59.4)	302 (55.4)	170 (59.0)	185 (56.1)
Females	219 (40.6)	243 (44.6)	118 (40.9)	145 (43.9)
Race
White	390 (72.4)	379 (69.5)	209 (72.6)	230 (69.7)
Black	34 (6.3)	55 (10.1)	20 (6.9)	26 (7.9)
Asian	64 (11.9)	46 (8.4)	35 (12.2)	30 (9.1)
Other*	10 (1.9)	0 (0)	5 (1.7)	0 (0)
Unknown	41 (7.6)	65 (11.9)	19 (6.6)	44 (13.3)
Ethnicity
Hispanic	55 (10.2)	102 (18.7)	28 (9.7)	62 (18.8)
Non-Hispanic	446 (82.8)	314 (57.6)	237 (82.3)	192 (58.2)
Unknown	38 (7.0)	129 (23.7)	23 (8.0)	76 (23.0)
Country of Birth
U.S. born	390 (72.3)**	222 (40.7)**	207 (71.9)**	130 (39.4)**
Foreign born	78 (14.5)**	122 (22.4)**	44 (15.3)**	68 (20.6)**
Unknown	71 (13.2)**	201 (36.9)**	37 (12.9)**	132 (40.0)**
Family history of ALS	17 (3.15)	22 (4.0)	10 (3.8)	15 (4.8)
Dementia diagnosis	34 (6.3)	22 (4.0)	18 (6.3)	15 (4.7)
El Escorial criteria
Definite, Probable, & Probable-lab supported	422 (78.3)	426 (78.2)	240 (83.3)	260 (78.8)
Possible	110 (20.4)	71 (13.0)	43 (14.9)	45 (13.6)
Unclassifiable	7 (1.3)	48 (8.8)*	5 (1.7)	25 (7.6)
Mean (Range)
Age at diagnosis	62.2 [14y-94y]	60.8 [14y-90y]	65.2 [32–92y]	62.4 [17–90y]
Age at symptom onset	60.6 [13y-94y]**	58.8 [11y-90y]**	63.7 [28–92y]	60.4 [17–90y]

*Other includes those of mixed race. **Significant at p-value of 0.05 (SFBA vs. LA).

Figure 1. Age-specific incidence of ALS, SF Bay Area and Los Angeles counties, 2009–2011.

Table II. Age-standardized incidence estimates and standardized rate ratios (SRR) for San Francisco Bay Area (SFBA) and Los Angeles County (LA), 2009–2011.

Characteristic	SFBA Rate per 100,000 (95% CI)	LA Rate per 100,000 (95% CI)	SRR Rate per 100,000 (95% CI)
Total	2.01 (1.8–2.3)	1.17 (1.0–1.3)	1.72 (1.47–2.0)
Gender
Males	2.60 (2.2–3.0)	1.40 (1.2–1.6)	1.80 (1.7–2.0)
Females	1.50 (1.3–1.8)	1.00 (0.8–1.1)	1.60 (1.5–1.7)
Age group, years*
30–39	0.30 (0.1–0.7)	0.23 (0.1–.0.4)	1.28 (0.4–4.2)
40–49	1.27 (0.8–1.9)	0.96 (0.7–1.3)	1.33 (0.8–2.3)
50–59	3.22 (2.5–4.2)	2.04 (1.6–2.6)	1.58 (1.1–2.3)
60–69	6.99 (5.6–8.6)	3.95 (3.2–4.9)	1.77 (1.3–2.4)
70–79	11.71 (9.3–14.6)	5.94 (4.7–7.4)	1.97 (1.4–2.7)
80+	6.39 (4.3–9.1)	3.18 (2.1–4.5)	2.01 (1.2–3.4)
Race**
White	2.49 (2.2–2.9)	1.4 (1.2–1.6)	1.51 (0.9–2.5)
Black	1.52 (0.9–2.4)	1.03 (0.7–1.5)	1.47 (0.8–2.7)
Asian	1.00 (0.7–1.4)	0.66 (0.5–0.9)	1.78 (1.5–2.2)
Ethnicity
Hispanic	1.57 (1.0–2.3)	0.66 (0.5–0.9)	2.38 (1.5–3.8)
Non-Hispanic	1.89 (1.7–2.2)	1.01 (0.9–1.2)	1.88 (1.5–2.3)

*Counts for incident cases under 30 years of age were insufficient to calculate rates.

**Due to missing race and ethnicity data, actual incidence rates are likely higher and SRRs are likely lower than presented.

Figure 2. Age-adjusted race and ethnicity specific incidence of ALS, SF Bay Area and Los Angeles counties, 2009–2011.