Two simple tests can indicate a probable diagnosis of fibromyalgia (FM) in patients with chronic pain, according to a study published online Oct. 23 in the Journal of Evaluation in Clinical Practice.
Kim D. Jones, Ph.D., from Oregon Health and Science University in Portland, and colleagues studied 352 patients scheduled for routine examination in two primary care practices. The cohort included 52 patients with a chart diagnosis of FM, 108 with chronic pain but not FM, and 192 with neither pain nor FM. Participants were assessed for tenderness to digital pressure at 10 locations, pain evoked by a blood pressure (BP) cuff, and a single question: “I have a persistent deep aching over most of my body.”
The researchers found that compared with patients with chronic pain but without FM, patients with FM endorsed the single question substantially more (7.4±2.9 versus 3.2±3.4) and showed greater bilateral digital-evoked tenderness (6.1±3.1 versus 2.4±2.4) and BP cuff-evoked pain (132.6±45.5 versus 169.2±48 mmHg). The BP cuff-evoked pain became non-significant on multivariate analysis. On further analyses, a useful screening test was provided by pain on pinching the Achilles tendon at 4 kg/pressure over four seconds and positive endorsement of the single aching question.
“These results suggest that two tests, taking less than one minute, can indicate a probable diagnosis of FM in a chronic pain patient,” the authors write. “In the case of a positive screen, a follow-up examination is required for confirmation or refutation.”