Case-Finding for MS Prevalence Studies in Small Communities Requires a Community-Based Approach

Abstract

In response to citizen concerns in 5 small Illinois towns, community-based case-finding determined the prevalence of multiple sclerosis (MS). Potential cases were identified through town meetings, publicity, advocacy groups and local volunteer outreach coordinators. Estimated prevalence based on available medical records for self-identifying individuals for 3 of the 5 communities was high (218–231 per 100,000 population) compared to other studies. Scanning databases in medical offices used in many other studies may miss MS cases; yet tracking medical records is labor-intensive and sometimes restricted by privacy guidelines. MS registries could improve case-finding accuracy and efficiency.

Incidence and Prevalence of Multiple Sclerosis in the Americas: A Systematic Review

“…While chart reviews are often considered the gold standard for identifying cases of MS [36], they are resource intensive, complicated by privacy requirements, and not practical to conduct at a population level in large jurisdictions [9,37]. Self-reported or community-based case ascertainment may identify those individuals with MS who do not regularly utilize medical services but are limited by the potential for recall bias and diagnostic inaccuracy [9].…”

“…Regardless of the sources used, researchers should consider the use of capture-recapture methodology to evaluate the completeness of the ascertainment and to correct for underascertainment [42,43,44]. Another option includes the designation of MS as a reportable condition or the development of a national or international registry [36,37,45]. Experience with such endeavors is growing and successful registries are emerging in other rare diseases [46].…”

Defining and analyzing geoepidemiology and human autoimmunity

“…For instance, striking autoimmune disease frequencies in a case of a well defined community possessing a genetic composition distinct form that of the neighbouring regions (e.g., the island of Sardinia); could point to a shared genetic susceptibility [47,48]. In other cases, a 'hotspot' may not represent a distinct ethnic group, but rather an exact location of a known potential environmental exposure (e.g., hazardous waste sites) [49]. Therefore, geoepidemiology provides an additional tool for distinguishing potential risk factors.…”

“…In response to citizen concerns in five small Illinois (US) rural towns, subsequent investigations recently reported among the highest MS prevalence rates ever documented (up to 300 cases per 100,000 population) [49]. Of note, an analysis in one of these towns (Morrison) has revealed no significant commonalities in the backgrounds of disease cases other than residence, raising the possibility of some environmental cause, yet to be appropriately explored.…”

“…In fact, two of the investigated hotspots were situated on US Environmental Protection Agency (EPA) Superfund clean up sites (a program to clean up uncontrolled hazardous waste sites), one town being home to a closed Army depot and the other previously being the site of significant environmental heavy-metal exposure from a zinc smelter. Of the three remaining towns, the first had sludge from the Chicago Metropolitan Sanitary District spread on its agricultural fields; the second (Morrison) is home to an electrical products plant; and the last is an agricultural community subject to fertilizer use and pesticide spraying [49].…”