Demographic data and clinical characteristics
From 327 study patients, 217 (66.4%) had extALS and 110 (33.6%) buALS.
We observed a female predominance among ALS patients (189/327, 58%).
The proportion of women with buALS (73/110, 66%; p <
0.005) was significantly higher than for extALS (116/217, 53%; p< 0.005). Among all 327 ALS patients, 296 (91%) had died by
the time of data retrieval. In the buALS group, 106 of 110 (96%)
patients had died, compared to 190 of 217 (88%) patients in the extALS
group. A total of 176 new ALS diagnoses were made during the 5-year
study period.
The mean age at symptom onset in the buALS group (66 years) was
significantly higher compared with the extALS group (59 years; p< 0.001), however in neither group was it associated with
gender. A higher age significantly associated with a shorter overall
survival time (r = -0.333; p < 0.001). Mean survival
was 47 months among all patients (95% CI 41.5–53.3), 55 months (95%
CI 46.5–63.7) in the extALS group, and 34 months (95% CI 28.9–38.7)
in the buALS group. Thus, survival in the extALS group was significantly
longer (p < 0.005; Figure 1). The clinical
characteristics for all study patients as well as a comparison of buALS
and extALS patients appear in Table 1.