Primary care providers are increasingly expected to recognize and treat fibromyalgia (FM) without significant interaction with rheumatologists. The purpose of this study was to evaluate the potential usefulness of 3 simple measures (tenderness to digital pressure, BP cuff-evoked pain, and a single patient question) as a screening test for possible FM in a patient with chronic pain.
A total of 352 patients (mean age 50 ± 16.3 years, 70% female) scheduled for routine examination in 2 primary care practices were studied. They were comprised of 52 patients (14.8%) who carried a chart diagnosis of FM, 108 (30.7%) with chronic pain but not FM, and 192 who had neither pain nor FM (54.5%). Subjects were assessed for tenderness to digital pressure at 10 locations, BP cuff-evoked pain, and a single question, "I have a persistent deep aching over most of my body" (0-10).
FM patients endorsed the single deep ache question substantially more than those with chronic pain but without FM (7.4 ± 2.9 vs 3.2 ± 3.4; P < .0001) and exhibited greater bilateral digital evoked tenderness (6.1 ± 3.1 vs 2.4 ± 2.4, P < 0.0001), and BP-evoked pressure pain (132.6 mmHg ±45.5 vs 169.2 mmHg ±48.0, P < 0.0001). However, on multivariate logistic regressions, the BP cuff-evoked pain became non-significant. On further analyses, a useful screening test was provided by: (1) pain on pinching the Achilles tendon at 4 kg/pressure over 4 seconds, and (2) and positive endorsement of the question "I have a persistent deep aching over most of my body".
These results suggest that 2 tests, taking less than 1 minute, can indicate a probable diagnosis of FM in a chronic pain patient. In the case of a positive screen, a follow-up examination is required for confirmation or refutation.