information:filtering, information:highlighting, linguistic:paraphrasing, structural:scholar_edition, stylistic:tone
Potential for incident under-reporting

Statistics on the reliability of incident reporting for injuries related to manipulation of the cervical spine vary. The RAND study assumed that only 1 in 10 cases would have been reported. However, Edzard Ernst surveyed neurologists in Britain for cases of serious neurological complications occurring within 24 hours of cervical spinal manipulation by various types of practitioners; 35 cases had been seen by the 24 neurologists who responded, but none of the cases had been reported. He concluded that under-reporting was close to 100%, rendering estimates "nonsensical." He therefore suggested that "clinicians might tell their patients to adopt a cautious approach and avoid the type of spinal manipulation for which the risk seems greatest: forceful manipulation of the upper spine with a rotational element." The NHS Centre for Reviews and Dissemination stated that the survey had methodological problems with data collection. Both NHS and Ernst noted that bias is a problem with the survey method of data collection.