. 2019 May 28;51(Suppl 1):2–14. doi: 10.1080/07853890.2018.1564360

Table 3.

GRADE Profile for studies evaluating the impact of dietary interventions on PRO and inflammation in FM patients.

Dietary interventions compared to usual treatment in Fibromyalgia patients
Certainty assessment							Summary of findings
Participants (studies) Follow-up	Risk of bias	Inconsistency	Indirectness	Imprecision	Publication bias	Overall certainty of evidence	Study event rates (%)		Relative effect (95% CI)	Anticipated absolute effects
Participants (studies) Follow-up	Risk of bias	Inconsistency	Indirectness	Imprecision	Publication bias	Overall certainty of evidence	With usualtreatment	With Dietaryinterventions	Relative effect (95% CI)	Risk withusualtreatment	Risk difference with Dietary interventions
Pain in FM (CRITICAL OUTCOME, assessed with Questionnaires: FIQ, FIQR; Scale from 0–100)
RCTs
161 (2 studies) (6 months) [18,32]	serious^a^,^b	serious^c	not serious	serious^d	none	⨁◯◯◯ VERY LOW	83	78	–	–	The mean FIQ in intervention group was 4.27 lower (7.3 lower to 1.24 lower)
Observational
82 (3 studies) (5–7 months) [21,22]	serious^a^,^e^,^f^,^g^,^h^,ⁱ	not serious	not serious	serious^d	none	⨁◯◯◯ VERY LOW	–	82	–	–	–
Pain in FM (CRITICAL OUTCOME, assessed with VAS; Scale from 1–10)
RTCs
105 (2 studies) (3 months) [17,19]	serious^a^,^e^,ⁱ^,^j^,^k	serious^l^,^m	seriousⁿ	serious^d	none	⨁◯◯◯ VERY LOW	51	54	–	–	The mean VAS in intervention group was 0.16 lower (0.58 lower to 0.26 higher)
Fatigue in FM (CRITICAL OUTCOME, assessed with FIQ and FIQR; Scale from 0–100)
RCTs
161 (2 studies) (6 months) [18,32]	serious^a^,^b	serious^c	not serious	serious^d	none	⨁◯◯◯ VERY LOW	83	78	–	–	not pooled
Observational
82 (3 studies) (1–7 months) [20,21^,22]	very serious^a^,^e^,^f^,^g^,^h^,ⁱ	not serious	not serious	serious^d	none	⨁◯◯◯ VERY LOW	–	82	–	–	–
Quality of Sleep in FM (IMPORTANT OUTCOME, assessed with PSQI; Scale from 0–21)
RCTs
161 (2 studies) (6 months) [18,32]	serious^a^,^b	serious^c	not serious	serious^d	none	⨁◯◯◯ VERY LOW	83	78	–	–	The mean PSQI in intervention group was 1.22 lower (2.05 lower to 0.4 lower)
Anxiety in FM (IMPORTANT OUTCOME, assessed with STAI, EQ-5D)
Observational
62 (2 studies) (1–5 months) [20,22]	very serious^a^,^e^,^f^,ⁱ	not serious	not serious	serious^d	none	⨁◯◯◯ VERY LOW	–	62	–	–	–
Depression in FM (IMPORTANT OUTCOME, assessed with BDI; Scale from 0–50)
RCTs
194 (3 studies) (3–6 months) [16,18,19]	very serious^a^,^b^,^e^,^j	serious^c^,^l^,^m	not serious	serious^d	none	⨁◯◯◯ VERY LOW	98	96	–	–	The mean BDI in intervention group was 0.86 lower (1.79 lower to 0.07 higher)
Observational
31 (1 study) (5 months) [22]	serious^a^,^e^,^f^,ⁱ	not serious	not serious	serious^d	none^o	⨁◯◯◯ VERY LOW	–	31	–	–	–
Quality of Life in FM (CRITICAL OUTCOME, assessed with SF-12, HAQ)
RCTs
108 (2 studies) (3–6 months) [16,19]	serious^a^,^b^,^e	serious^c^,^l^,^m	not serious	serious^d	none	⨁◯◯◯ VERY LOW	55	53	–	–	not pooled
Quality of Life in FM (CRITICAL OUTCOME, assessed with EQ-5D, SF-36, HAQ)
Observational
82 (3 studies) (4 weeks to 7 months) [20,21,22]	very serious^a^,^e^,^f^,^g^,^h	not serious	not serious	serious^d	none	⨁◯◯◯ VERY LOW	–	82	–	–	–
Gastrointestinal symptoms in FM (IMPORTANT OUTCOME, assessed with IBS-SSS)
Observational
31 (1 study) (1 month) [20]	serious^a^,^e^,^f	not serious	not serious	serious^d	none^o	⨁◯◯◯ VERY LOW	–	31	–	–	-
Inflammation in FM (IMPORTANT OUTCOME, assessed with IL6 biomarkers)
RCTs
86 (1 study) (6 months) [18]	not serious^a	not serious	not serious	serious^d	none	⨁⨁⨁◯ MODERATE	43	43	–	–	The mean IL6 in intervention group was 0.7 lower (1.31 lower to 0.09 lower)
Inflammation in FM (IMPORTANT OUTCOME, assessed with PCR biomarker)
RCTs
86 (1 study) (6 months) [18]	not serious^a	not serious	not serious	serious^d	none	⨁⨁⨁◯ MODERATE	43	43	–	–	The mean PCR in intervention group was 0.6 lower (1.06 lower to 0.14 lower)

RCTs: Randomized Controlled Trials; CI: Confidence interval.

^{^a}

According to the nature of a dietary study, there isn't possible to blind population. As so, this was not considered a factor to downgrade studies.

^{^b}

Study does not use an independent control group (two different interventions are applied).

^{^c}

Heterogeneity of the population in pharmaceutical therapy, at baseline.

^{^d}

Sample size is always reduced in all studies; the Optimal Information Size (OIS) is never estimated.

^{^e}

Study did not apply intention-to-treat analysis, despite presenting >5% of loss of follow up and/or do not justify missing data.

^{^f}

Study has no control group.

^{^g}

Do not control possible confounding factors, as the increased Omega 3 ingestion, which is known to have an anti-inflammatory potential.

^{^h}

Do not justify missing data.

^ⁱ

Do not control possible confounding factors, as medical therapy.

^{^j}

Study has no randomization.

^{^k}

Study does not indicate how the randomization was done.

^{^l}

Heterogeneity of the population in BMI, at baseline.

^{^m}

Heterogeneity of the population in pain level, at baseline.

^ⁿ

Study evaluates only pain, ignoring other important symptoms for the patient.

^{^o}

Single study.