A prospective study of the 1-year incidence of fibromyalgia after acute whiplash injury

OBJECTIVE To measure the 1-year incidence of fibromyalgia in a cohort of acute whiplash-injured participants. METHODS Consecutive acute patients with whiplash were assessed via the 2010 Modified American College of Rheumatology (ACR) criteria for fibromyalgia at 3 months, 6 months and 1 year postinjury. At each of these follow-up points, participants were also examined for recovery from whiplash injury. RESULTS Of an initial 268 participants, data on recovery was available for 264 participants during the 1-year follow-up period. At the 3-month follow-up, 62% (167/268) of participants reported recovery from their whiplash injuries. At 6 months, 76% (203/268) reported recovery, and at 1 year 82% (216/264) reported recovery. At 3 and 6 months follow-up none of the participants met the 2010 Modified ACR Criteria for fibromyalgia, but fibromyalgia criteria were met for 2 (of 264) seen at the 1-year follow-up, yielding a 1-year incidence of 0.8% (95% CI 0.1% to 3.0%). CONCLUSIONS In the primary care setting, a significant proportion of patients with whiplash recover from whiplash injury at 1 year, and the incidence of fibromyalgia after acute whiplash injury is very low. The impression that fibromyalgia is common after whiplash injury may be due to the failure to exclude precollision fibromyalgia cases or due to referral bias of non-recovered patients.