Preparing for a U.S. National ALS Registry: Lessons from a pilot project in the State of Georgia

Abstract

Our objective was to investigate the utility of existing data sources for identifying cases of amyotrophic lateral sclerosis (ALS) and related motor neuron diseases (MND) in the State of Georgia. Data were acquired from Medicare, Medicaid, Veterans Administration, Emory Healthcare, community neurologists, the ALS Association, and mortality records for ALS/MND patients residing in Georgia during 2001–2005. A neurologist used abstracted medical records to verify the diagnosis of ALS/MND. The positive predictive value (PPV) of an ICD code for a verified diagnosis of ALS was estimated. Simple ‘rules’ were developed to improve PPV. Results showed that a total of 2413 unique potential cases were identified in existing data sources. Medical records of 579 cases were available for review; the diagnosis of ALS (or a related MND) was confirmed in 486 (PPV = 84%) cases. Predictive rules, which permitted classification of ∼80% of the chart-reviewed population, improved PPV to 96–98%. In conclusion, existing data sources are useful for identifying cases of ALS/MND; most data sources contribute a substantial number of unique cases. Predictive algorithms may permit correct classification of a large proportion of cases without the need for verification based on medical record review.

Key words::

• Epidemiology
• neuroepidemiology
• ALS Registry
• ICD code
• positive predictive value

Acknowledgements

We gratefully acknowledge the many people who assisted our acquisition of data from various sources. These include Wendy Kaye, Oleg Muravov, Jenny Wu and Judy Smith at ATSDR/CDC; Keith Sanders at Atlanta Neurology; David Williams at Peachtree Neurology; Nancy Carter at Emory Healthcare, Meraida Polak and members of the Emory ALS Clinic; Rana Bayakly at the Division of Public Health in the Georgia Department of Community Health; Linda Wojno at the Georgia Chapter of the ALS Association; Vicki Cuneen at the Georgia Chapter of the Muscular Dystrophy Association (MDA); James Knowles and Karen Fisher at the MDA clinic in Roosevelt Warm Springs; Kevin Boylan at the Mayo Clinic in Jacksonville, Florida; and Michael Rivner and Demetric Hillman at the Medical College of Georgia. We also thank Michael Wittie and Masha Goodman for their assistance with data abstraction. Finally, we thank John Young at the Georgia Cancer Registry for his advice and guidance. This research was funded by a contract from ATSDR/CDC.

Declaration of interest: The authors report no conflicts of interest.