Table 3. Summary of the GRADE quality of evidence assessment.
| Quality Assessment | Number of Patients | SMD/OR (95% CI) | Quality | ||||||
|---|---|---|---|---|---|---|---|---|---|
| # Studies | Risk of Bias | Inconsistency | Indirectness | Imprecision | Publication Bias | FM | Control | ||
| FM vs. Healthy Controls (All studies) | |||||||||
| 15 | Not serious | Serious | Not serious | Not serious | Not serious | 558 | 412 | SMD | ⊕⊕⊕⊕ Moderate† |
| 0.72 | |||||||||
| [0.12, 1.31] | |||||||||
| FM vs. Healthy Controls (Plasma) | |||||||||
| 3 | Not serious | Not serious | Not serious | Not serious | Not serious | 118 | 66 | SMD | ⊕⊕⊕⊕ Mild |
| 0.42 | |||||||||
| [0.11, 0.73] | |||||||||
| FM vs. Healthy Controls (Serum) | |||||||||
| 12 | Not serious | Serious | Not serious | Not serious | Not serious | 440 | 346 | SMD | ⊕⊕⊕⊕ Moderate† |
| 0.80 | |||||||||
| [0.06, 1.55] | |||||||||
| FM vs. Healthy Controls (Female) | |||||||||
| 11 | Not serious | Serious | Not serious | Not serious | Not serious | 428 | 281 | SMD | ⊕⊕⊕⊕ Moderate† |
| 0.77 | |||||||||
| [0.30, 1.24] | |||||||||
| Gene Polymorphism | |||||||||
| 4 | Not serious | Serious | Not serious | Not serious | Not serious | NA | NA | OR | ⊕⊕⊕⊕ Moderate† |
| 1.31 | |||||||||
| [0.66, 2.58] | |||||||||
Abbreviations: CI: confidence interval, SMD: Standardized Mean Difference, OR: Odds Ratio, NA: Not Applicable
†Moderate due to serious inconsistencies and high heterogeneity in meta-analysis