Which Fibromyalgia Questionnaire Should a Clinic Actually Use?
and what counts as a real improvement

September 2026 · 9 min read · Clinical Measurement Guide

Bottom line: Fibromyalgia is diagnosed today under the ACR 2016 criteria — the Widespread Pain Index (WPI) together with the Symptom Severity Scale (SSS) — and no longer by pressing 18 tender points. The self-report version of those criteria is explicitly not valid for clinical diagnosis of an individual patient, only for research. A 14% change on the total FIQ score is the minimal clinically important difference. And the three controlled PEMF trials in fibromyalgia reach different conclusions that line up almost perfectly with the instrument each one chose.

Why "Fibromyalgia Questionnaire" Means Two Different Things

The phrase covers two entirely separate families of instrument, and confusing them is a common clinical error. The first family is diagnostic: it asks whether the patient meets criteria. That is the Widespread Pain Index (WPI, range 0–19) together with the Symptom Severity Scale (SSS, range 0–12) from the American College of Rheumatology criteria.

The second family measures impact: not whether a diagnosis exists, but how severe things are today and how much has changed since the last visit. That is the Fibromyalgia Impact Questionnaire (FIQ) and its revision, the FIQR. A patient can meet the diagnostic criteria and still score low on the FIQR, and the reverse is equally possible.

Why this matters operationally: a clinic that measures only diagnosis can never demonstrate improvement, and a clinic that measures only impact never establishes that it is treating fibromyalgia at all. Both are needed, at different points in time.

How Is Fibromyalgia Diagnosed Under the ACR 2016 Criteria?

Diagnosis rests on the distribution of pain combined with symptom severity, not on tender-point examination, which was dropped in 2010. The 2016 revision (Wolfe et al., Semin Arthritis Rheum 2016;46(3):319-329, PubMed 27916278) sets the threshold at WPI ≥ 7 together with SSS ≥ 5, or alternatively WPI of 4–6 together with SSS ≥ 9.

Two further conditions apply: generalized pain, defined as pain in at least 4 of 5 body regions, and symptoms present at a similar level for at least three months. The generalized pain criterion was the central addition of 2016, introduced specifically to stop regional pain syndromes being misclassified as fibromyalgia.

Reviewing 14 validation studies, the authors report median sensitivity of 86% and specificity of 90% against the 1990 and clinical criteria. One further statement carries real clinical weight: the diagnosis is valid irrespective of other diagnoses — fibromyalgia neither excludes another illness nor is excluded by one.

Can an Online Self-Assessment Diagnose Fibromyalgia?

No — and that is an explicit statement in the paper that defined the criteria. Wolfe and colleagues conclude that the self-report version of the criteria is not valid for clinical diagnosis in individual patients, and is valid for research studies only; only the physician-administered version supports an individual diagnosis (PubMed 27916278).

For the patient, this means a high score on an online questionnaire is a reason to seek an assessment, and only the assessment gives the answer. For the clinic the implication is sharper: a self-completed form is not a diagnostic document, and relying on it as though it were exposes the practitioner. The correct use is as a pre-appointment triage form, with the WPI and SSS completed in the consultation itself.

The third point is a safety point. Because the diagnosis is valid irrespective of other diagnoses, a positive score does not close the workup. Widespread pain can also express inflammatory disease, hypothyroidism or nutritional deficiency, and excluding those is the treating physician's responsibility.

What Counts as Real Improvement — and Why the Number Is 14%?

A 14% change in the total FIQ score is the minimal clinically important difference, derived from a sample of 2,228 patients. The work establishing it (Bennett et al., J Rheumatol 2009;36(6):1304-11, PubMed 19369473) pooled three placebo-controlled trials and anchored score change against the patient's own global impression of change. The result: an MCID of 14% (95% CI 13–15), and 13% (12–14) for the stiffness item.

The same work produced severity bands that are convenient in daily use: a total FIQ score of 0 to 39 is mild impact, 39 to 59 moderate, and 59 or above severe. Mean baseline across the pooled trials was 62 — that is, severe.

The revised instrument, the FIQR (Bennett et al., Arthritis Res Ther 2009;11(4):R120, PubMed 19664287), is built entirely on 0–10 numeric scales and is far simpler to score. In its validation, mean completion time was 1.3 minutes, with about one minute to score. It also discriminated well between populations: a mean total of 56.6 in fibromyalgia, against 28.6 in rheumatoid arthritis or lupus, 17.3 in major depressive disorder and 12.1 in healthy controls.

What Did the Double-Blind PEMF Trial in Fibromyalgia Find?

The one positive controlled trial found significant improvement across all four measures used — but only the actively treated group held its FIQ gain. A randomized, double-blind, sham-controlled trial from the Physical Medicine and Rehabilitation hospital in Ankara (Sutbeyaz et al., Clin J Pain 2009;25(8):722-8, PubMed 19920724) enrolled 56 women aged 18–60, randomized to PEMF or sham, 30 minutes twice daily for three weeks.

At the end of treatment the PEMF group showed significant improvement on the FIQ, on the pain VAS, on the Beck Depression Inventory and across all SF-36 domains. The sham group improved on every measure too — except the total FIQ score. At the 12-week follow-up only the BDI and SF-36 gains remained in the sham group, while the treatment group retained its FIQ, VAS and SF-36 pain improvements. This is precisely the case in which the choice of instrument determines the conclusion.

Why Did the Largest Trial Find No Separation From a Sham Device?

The largest trial in this field is also the most negative, and that has to be said plainly. A crossover study from Central Finland Central Hospital and the University of Jyväskylä (Multanen et al., Bioelectromagnetics 2018;39(5):405-413, PubMed 29709070) enrolled 108 women, each of whom completed 12 weeks with an active device and 12 weeks with an inactive one, in random order. Pain fell by 12 VAS points on the active arm and 11 on the inactive arm — and the per-protocol analysis found no difference between them on any outcome. The authors' conclusion is explicit: the therapy was not effective. A published comment on the paper appeared in the same journal in 2019 (Havas, Bioelectromagnetics 2019;40(8):611, PubMed 31579955).

Against that, a single-blind trial from ASL3 in Genoa and IRCCS Humanitas in Milan (Giovale et al., Rheumatol Immunol Res 2022;3(2):77-83, PubMed 36465321) in 21 women of median age 59 did find separation: WPI fell 12.90 points versus 1.91 on placebo (difference 10.99, p<0.001), SSS 4.10 versus 2.00 (p<0.05) and VAS 48 versus 16.82 (p<0.01) — but the FIQ and SF-36 improvements did not reach significance. One author is employed by the company that supplied the device, as the investigators themselves declared.

Comparison: The Three Trials and What Each One Measured

Placing the three studies side by side explains the contradiction better than any mechanistic discussion. The row that matters most is the one naming the instrument that failed to separate.

One point deserves emphasis: the negative trial tested a low-intensity field device designed for prolonged home use, not a clinical system. That distinction is not semantic, and it is the reason a result from one cannot be transferred to the other in either direction.

Clinical Implementation: A Seven-Minute Measurement Protocol

The sequence below is built so that each step produces a document that can be shown to an insurer, a referring physician or the patient. It takes about seven minutes at the first visit and about three at each follow-up.

1. Before the first session: complete the WPI and SSS per ACR 2016 in the consultation, by the clinician — not as a form the patient submits from home.
2. Baseline: record a full FIQR. Reported completion time in the validation study is 1.3 minutes.
3. Pain: record a 0–100 VAS separately from the FIQR, because it is the measure that separated most strongly in two trials out of three.
4. Measurement points: repeat everything at week 4 and week 12 — the timepoints at which Sutbeyaz measured, follow-up included.
5. Decision threshold: fix in advance that improvement counts only above 14% on the FIQ. A smaller change is evidence of neither success nor failure.
6. Do not merge instruments: keep the WPI and SSS separate from the FIQR. That is where Giovale found separation, and the FIQ is where it was not found.
7. Sleep and mood: record them separately. In Sutbeyaz the sham group improved on these too, which makes them poor indicators of treatment effect.

When PEMF Is Relevant in Fibromyalgia — and When It Is Not

It is relevant as a non-pharmacological treatment for a patient already diagnosed, together with the rest of their care, and it is not a substitute for medical workup. The evidence set out above does not support a promise of recovery, and the largest trial in the field found no separation from an inactive device.

What it does support is a reasonable safety profile, a low treatment burden and the absence of systemic side effects — three real advantages in a population whose tolerance of medication is poor. In fibromyalgia, where adherence to long-term drug therapy is itself a problem, those are legitimate clinical considerations.

What is not supported, and must not be written: that the treatment "cures" fibromyalgia, that it replaces physiotherapy, graded exercise or cognitive behavioural therapy, or that it holds regulatory clearance for this indication. Regulatory status is specific to a model and an indication, and the documentation should be requested from the supplier.

From Field Experience Across the PainFree Network

This section describes operational observations from the field and is not trial results. Three points recur in clinics that treat widespread pain:

• The intake questionnaire is what makes the file defensible. Clinics that record WPI and SSS at intake can explain later why they treated the patient at all; clinics that record only pain scores cannot.
• The decision threshold has to be set before treatment starts. Agreeing the 14% FIQ threshold in advance is what keeps the review conversation factual instead of impressionistic.
• Contraindications are caught on a written form. Active electronic implants, pregnancy and active malignancy in the treatment area are asked in writing at intake, not verbally mid-session.

What This Means for Clinic Owners and Investors

Fibromyalgia is a large, underserved and loyal patient population whose response to standard pharmacotherapy is poor. The commercial question is not whether an electromagnetic field cures the condition — nothing here says it does — but whether a clinic can document outcomes well enough to justify what it charges and to earn referrals. 70+ Israeli clinics serving a population of 9M — now expanding to the Philippines have added the system, and the ones that succeed with this population are distinguished by measurement discipline rather than by equipment. In the Philippines market, a treatment session in this category is typically priced at ₱1,500–₱2,500.

Frequently Asked Questions

What is a fibromyalgia questionnaire and how is it completed?
It is a collective term for two kinds of instrument. The first is diagnostic — the Widespread Pain Index (WPI, 0–19) together with the Symptom Severity Scale (SSS, 0–12) under the ACR 2016 criteria. The second measures impact — the FIQR, built on 0–10 scales and taking about a minute and a half. The first is completed in the clinic with the practitioner; the second can be completed alone.

Can fibromyalgia be diagnosed with an online questionnaire?
No. The paper defining the criteria (PubMed 27916278) states explicitly that the self-report version is valid for research only and not for clinical diagnosis of an individual patient. A high online score is a good reason to see a physician, not a diagnosis. Remember also that fibromyalgia does not exclude other illnesses, so the workup should continue.

What is a high FIQ score?
Using the severity classification derived from 2,228 patients (PubMed 19369473): 0 to 39 represents mild impact, 39 to 59 moderate, and 59 or above severe. Mean baseline across the clinical trials examined was 62 — in the severe range. The score measures function and impact, not diagnosis.

How much improvement counts as meaningful in fibromyalgia treatment?
A 14% change in the total FIQ score (95% CI 13–15), and 13% on the stiffness item. That is the minimal clinically important difference — the threshold above which patients themselves report a noticeable change. A smaller improvement can be statistically significant and still mean nothing to the patient, which is why the threshold should be agreed before treatment begins.

Does PEMF help fibromyalgia?
In two of three controlled studies, yes — on the pain measures. A double-blind sham-controlled trial in 56 women found significant improvement in FIQ, pain and quality of life that was still present 12 weeks after treatment ended (PubMed 19920724). A second study found the widespread pain index fall by 12.9 points against 1.9 on placebo, and pain intensity by 48 points against 16.8 (PubMed 36465321). Against this, the largest study — 108 women — found no separation at all from an inactive device (PubMed 29709070). The practical conclusion: a meaningful effect on pain is possible, it depends on device and protocol, and the only way to know whether it happened for a given patient is to measure before and after.

What is the difference between the WPI and the FIQR?
The WPI counts how many body regions were painful in the past week and forms part of the diagnosis. The FIQR measures how much the condition disrupts function today and is a monitoring tool. A patient can meet the WPI criterion and still score relatively low on the FIQR during a good period. The two measure different things, and a clinic wanting to document outcomes needs both.

Limitations of This Page

The three PEMF trials described here are small to moderate (21–108 participants), all were conducted in women, and the largest of them was negative. One carries a declared conflict of interest and another has a published comment attached to it in the same journal. The diagnostic and impact instruments described are validated tools but are not themselves treatments. Nothing here is individual medical advice, and both diagnosis and treatment decisions belong to the treating clinician. Regulatory clearance is model-specific — ask any supplier for the certificate covering the exact model offered to you, its indication and its expiry date.