title: Utility of capture-recapture methodology to assess completeness of amyotrophic lateral sclerosis case ascertainment.
abstract: BACKGROUND
  With the establishment of a national amyotrophic lateral sclerosis (ALS) registry in the United States, methods are needed to ascertain the completeness of case ascertainment, especially in view of the proposal to rely largely on existing data sources.
  
  
  METHODS
  Data about ALS patients residing in the 5-county metropolitan Atlanta area (within the State of Georgia) from 2001 to 2005 were categorized according to their source--ALS Association, clinical (Emory Healthcare, community neurologist, Veterans Health Administration, Veterans Benefits Administration), Medicare and death certificates. ALS diagnoses were verified using chart review. Capture-recapture analyses were carried out using log-linear modeling, stratified by age and race.
  
  
  RESULTS
  The final model (based on 798 cases), which included the 4 main sources and 3 two-way interaction terms, yielded an estimated total population of 880 (95% CI 816-965), indicating that the combination of case-finding methods identified about 90.7% of cases. The estimated 5-year period prevalence is 38.5/100,000 (95% CI 35.66-42.19).
  
  
  CONCLUSIONS
  This study highlights gaps in data based on existing data sources and illustrates a method for combining data from multiple sources to help facilitate the successful establishment of a US national ALS registry.
authors.affiliation: Division of Epidemiology, Department of Health Research and Policy, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Wittie
authors.forename: Lorene M
authors.initials: LM
authors.lastname: Nelson
authors.forename: Sharon
authors.initials: S
authors.lastname: Usher
authors.forename: Kevin
authors.initials: K
authors.lastname: Ward
authors.forename: Michael
authors.initials: M
authors.lastname: Benatar
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000453:epidemiology*; D002908:Chronic Disease; D015331:Cohort Studies; D015897:Comorbidity; D003625:Data Collection / Q000379:methods* / Q000706:statistics & numerical data; D057286:Electronic Health Records / Q000706:statistics & numerical data; D004827:Epilepsy / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology*; D038801:International Classification of Diseases; D043183:Irritable Bowel Syndrome / Q000453:epidemiology*; D008171:Lung Diseases / Q000453:epidemiology*; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D008875:Middle Aged; D008881:Migraine Disorders / Q000453:epidemiology*; D011237:Predictive Value of Tests; D015995:Prevalence; D055815:Young Adult