Case-finding for multiple sclerosis (MS) prevalence studies in small communities requires a community-based approach

Responding to citizens' concerns about excessive multiple sclerosis (MS) cases or “clusters” and perceived environmental hazards, a prevalence study was conducted in five small Illinois communities. The study, one of five in the nation funded by the Agency For Toxic Substances and Disease Registry (ATSDR), sought to identify all persons with MS living in these zip codes from 1998 to 2002. Participants completed a survey and consented to have their medical records reviewed by the consulting neurologist who verified the MS diagnosis. The community-based case-finding approach was unique compared to other MS prevalence studies. Recruitment methods tailored to rural communities were very successful in identifying potentially eligible individuals. Besides holding town meetings, using local outreach coordinators, contacting physicians, health departments and nursing homes, widespread regional media coverage increased study awareness. Cases were identified who did not visit neurologists and would have been missed in typical MS prevalence studies which search neurology databases. Three of the five communities had elevated levels of MS compared to national prevalence rates. No associations with environmental causes could be made. One-third of the cases had blood relatives with MS and all cases were of northern European ancestry, a risk factor for MS not widely known. The female to male ratio was triple national rates. The methodology was effective for conducting surveillance for a chronic autoimmune disease in rural areas and could be used for other chronic diseases where no registries exist. Community cooperation is essential for community-based case-finding to succeed.