Well, no one is quite sure. Scientists guess, based on studies of small chunks of the country, that the number hovers around 30,000, with some 5,000 new cases each year. “It is very difficult to estimate the incidence and prevalence of ALS because there are no national data available,” says Kevin Horton, ALS program administrator for the Agency for Toxic Substances and Disease Registry (ATSDR) in Atlanta. There have been suggestions that ALS is on the rise (see ARF related news story on Fang et al., 2009), but without solid numbers it is hard to know for sure.

Horton and the ATSDR plan to change that. On October 20, they opened a new National ALS Registry to the public. People with ALS can log on to be counted, entering their health history, family history, and work experience. Then, they can fill out specific surveys—covering topics such as military history or occupation—to help scientists determine whether those factors increase risk of disease. “Our hope,” Horton said, “is to find a common thread or a common theme.” Whether 30,000 people with ALS is a large enough sample to find statistically significant risk factors is an open question, but Horton said that the more data they have, the better.

ATSDR will also incorporate numbers from Medicaid, Medicare, and Veterans Affairs databases. The agency has been testing and developing the registry for four years, and in pilot programs with single states, determined that its methodology would be effective at capturing ALS cases. Pilot studies determined that Medicaid, Medicare, and the VA include most cases of ALS, but the open registry is necessary to catch those that are not in those records.

Using computer algorithms, the program will determine whether an entry truly represents a case of ALS. It will also make sure no one is counted more than once. ATSDR will compare the nationwide results to data gleaned from smaller, city- or state-based data to make sure the national registry has achieved an accurate sampling. Once the data have been collected and validated, perhaps in a few years’ time, qualified outside scientists will be able to use the database for their own studies.

ATSDR, a sister agency to the Centers for Disease Control and Prevention that had been focusing on environmental health, started considering this kind of ALS registry a decade ago, Horton said. Some citizens were worried about potential clusters of ALS in their neighborhoods. Similarly, research has suggested that ALS rates are unusually high in veterans (Horner et al., 2003). But there was no way to determine if a perceived cluster actually represented a high ALS rate.

The National ALS Registry will be similar to ATSDR-run registries, which have helped define clusters and risk factors for cancer. The ALS Registry was mandated by an act of Congress in 2008. Its 2011 fiscal year budget is $5.5 million, Horton said, and the project is expected to run indefinitely. Following their experience with the ALS Registry, ATSDR may establish other registries in the future.

The registry will not only be useful to researchers. “We want to make sure that people who come not only input data, but also get something beneficial out of it,” Horton said. When they log on, users will find the results of ATSDR’s data analysis, free access to published journal articles from the project, and links to ongoing clinical trials. In the future, Horton hopes to add a feature that will allow users to map their nearest ALS clinic.

“The National Registry provides an opportunity for all ALS patients to be engaged in ALS research,” wrote Lucie Bruijn, senior vice president for research and development at the ALS Association, in an e-mail to ARF. “It will provide important information about the disease throughout the USA, enabling scientists to explore potential environmental factors and demographics of the disease.”

The new registry joins PatientsLikeMe, another ALS database that has been running since 2004. On PatientsLikeMe, people with ALS or their caretakers can share their experiences with various symptoms and treatments. PatientsLikeMe aggregates the data into charts and graphs, and also makes the data available for research.—Amber Dance.