A simple screening test to recognize fibromyalgia in primary care patients with chronic pain

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.