OBJECTIVE: To develop and test an instrument to screen for
fibromyalgia syndrome (FM) in general population surveys.
METHODS: We designed a questionnaire with 4 pain and 2 fatigue
items. A positive screen was defined 2 ways: (1) positive
responses to all 4 items on pain, and (2) positive responses
to all pain and fatigue items. Sensitivity was tested in the
clinic on 31 outpatients with FM, specificity on 30
outpatients with rheumatoid arthritis (RA) and 30 healthy
controls. Test-retest reliability (TRR) was estimated in a
community survey of 672 noninstitutionalized adults. Positive
predictive value (PPV) was estimated as part of a community
survey of 3395 noninstitutionalized adults, in which 100 cases
of FM were confirmed by examination.
RESULTS: For pain
criteria alone sensitivity was 100% (95% confidence intervals
90.3%, 100%); in patients with RA specificity was 53.3%
(35.4%, 71.2%). For the pain plus fatigue criteria,
sensitivity was 93.5% (83.8%, 100%), and specificity in
patients with RA 80% (65.7%, 94.3%). In nonpatient controls,
specificity was 100% (89.3%, 100%) using either definition of
a positive screen. For those initially screening negative, TRR
was 100% (93.2%, 100%) using either definition. For positive
screens, TRR was 95.0% (88.8%, 100%) for the pain criteria
alone, and 81.0% (69.1%, 92.8%) for the combined criteria. PPV
was 56.8% (53.0%, 60.6%) using the pain criteria alone, and
70.6% (CI 55.3%, 85.9%) using the combined criteria.
CONCLUSION: The instrument appears to be useful in screening
for FM in general population surveys of noninstitutionalized
adults. Confirmation of FM among those who screen positive
requires a personal interview to reestablish pain duration and
distribution, and an examination for tender points.
White KP, Harth M, Speechley M, Ostbye T