Of that group, four survived to be released from the hospital. This could be a blow to Phillips, the only firm approved to sell AEDs directly to patients without a prescription. The study does not question the value of AEDs in public places like hospitals, schools, and emergency vehicles. Those settings usually have a number of people who are trained to use AEDs. But many of the incidents that beset the patients in the study occurred when no one else was home, meaning the AED could not be used. And in some cases, the AED was not used despite someone else being present. For these reasons, the study's authors concluded that spending money for a home AED is not a wise use of resources. The patients in the study had previously suffered heart attacks but were not considered at-risk enough to warrant having an implantable cardioverter-defibrillator. They had spouses or caregivers trained to use AEDs. When the AEDs were appropriately used, there was a 33% survival rate, but the sample size was so small that the numbers were not statistically significant. Rather than a springboard to mass marketing of home-use AEDs, the study mayÂ lead toÂ other things, such as better alert systems for when patients who are alone collapse, and better training in AED use and CPR for caregivers and companions. UPDATE: WebMD's spin emphasizes that the devices do work -- but other, less expensive options work just as well.