Survival and Cause of Death among a Cohort of Confirmed Amyotrophic Lateral Sclerosis Cases

Abstract

Introduction: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder. Estimates of survival from disease onset range from 20 to 48 months and have been generated using clinical populations or death records alone.

Methods: Data on a cohort of ALS cases diagnosed between 2009-2011 were collected as part of the Los Angeles and San Francisco Bay Area Metropolitan ALS Surveillance projects; death records 2009-2013 were linked to these confirmed cases to determine survival post diagnosis and factors associated with survival time.

Results: There were 618 cases identified and 283 of these died during the follow up time period. Median age at death was 64.3 years, and median survival time post-diagnosis was 2.6 years. Age at diagnosis and year of diagnosis were predictors of survival time in adjusted models; those diagnosed at age 80 or older had shorter survival than those diagnosed at age 50 or younger. Most (92%) had ALS noted as a cause of death.

Discussion: Survival post-diagnosis may be improved compared with previous reports. Age at diagnosis continues to be the strongest predictor of prognosis; recall case reporting bias may play a role in estimates of survival time.

Fig 1. Survival Curves of Selected California County ALS Cases Post-Diagnosis, 2009–2013.

Kaplan Meier estimate survival curves of ALS cases post-diagnosis from Los Angeles County and selected San Francisco Bay Area counties, by age at diagnosis, last assigned El Escorial criteria, whether seen at referral center and year of diagnosis (diagnosed 2009–2011, deceased 2009–2013).