Table 4

Categorisation of the Fragility and Reverse Fragility Index according to randomised controlled trial design, sample size, compliance assessment method and primary outcomes (n, median and IQR)

NFragility Index P-valueReverse Fragility Index P-value
 Single blind214.0 (2.5–10.5)0.38*7.0 (3.3–15.3)0.68*
 Open label247.0 (4.0–12.0)7.0 (6.0–10.5)
 Not reported2CNC10.5 (0.3–11.8)
Outcome categorisation
 Perinatal outcomes44.0 (3.0–21.5)0.34*7.0 (7.0–7.0)0.98*
 Outcomes related to the MetS and DM1511.5 (7.8–17.0)6.0 (2.5–7.5)
 Cardiovascular outcomes165.0 (3.8–8.3)10.5 (7.0–17.3)
 Outcomes related to NAFLD31.0 (1.0–1.0)4.0 (2.5–5.5)
 Other†95.0 (4.3–7.0)16.0 (13.0–28.0)
Composite outcome
 Yes‡156.0 (4.0–16.8)0.29§7.0 (7.0–7.0)0.85§
 No¶325.0 (3.3–8.5)7.0 (3.3–13.8)
Sample size
 <1000 patients205.0 (4.0–7.0)0.64§7.0 (2.0–13.0)0.57§
 ≥1000 patients277.0 (3.5–12.5)7.0 (6.0–14.8)
Dietary compliance assessment methods
 Questionnaires (FFQs, diet scores)/diet history225.0 (2.3–10.8)0.59*7.0 (6.3–13.0)0.035*
 Diet recalls or records74.5 (3.3–11.8)2.0 (1.5–2.5)
 Biomarkers186.0 (4.0–11.0)11.0 (6.0–27.3)
  • *Based on the Kruskal-Wallis test.

  • †First incidence of breast cancer, cataract surgery, osteoporotic fractures, return to robustness, depression.

  • ‡Maternal/offspring composite outcome, incidence of metabolic syndrome (MetS), cardiovascular (CV) mortality, composite CV events, optimal CV risk factor control, total cardiac events, total outcome endpoints.

  • §Based on the Mann-Whitney U test.

  • ¶incidence of gestational diabetes mellitus (GDM), atrial fibrillation, heart failure, type 2 diabetes mellitus (T2DM), depression, first invasive breast cancer, steatosis, non-fatal myocardial infarction, cataract surgery, diabetic retinopathy, osteoporotic fractures, need for T2DM medication, reversion to robustness, weight loss, non-alcoholic fatty liver disease (NAFLD) resolution, new symptomatic periphery artery disease cases, reversion of MetS.

  • CNC, could not be calculated; DM, diabetes mellitus; FFQ, food frequency questionnaire; ;IQR, interquartile range.