Table 3.
Summary design difference* estimates of the 31 meta-analyses that examined biomarkers for cardiovascular risk and included data from at least one observational study (OS) and one randomised controlled trial (RCT)
| Comparison | No of meta‑analyses | Design difference (95% CI) | I2 (95 % CI) | P value (Q) | |
|---|---|---|---|---|---|
| Random effects | Fixed effects | ||||
| All data | 31 | 0.24 (0.07 to 0.40) | 0.33 (0.23 to 0.43) | 39 (6 to 60) | 0.015 |
| Design contrast: | |||||
| RCT v prospective OS | 31 | 0.23 (0.07 to 0.40) | 0.33 (0.23 to 0.43) | 37 (2 to 59) | 0.023 |
| RCT v retrospective OS | 9 | 0.34 (−0.02 to 0.70) | 0.34 (−0.02 to 0.70) | 0 (0 to 65) | 0.457 |
| Type of meta-analysis: | |||||
| Of individual participant data | 7 | 0.42 (0.14 to 0.70) | 0.51 (0.37 to 0.65) | 50 (0 to 79) | 0.064 |
| Of published literature | 24 | 0.15 (−0.01 to 0.31) | 0.16 (0.02 to 0.30) | 10 (0 to 44) | 0.320 |
| Type of RCT: | |||||
| Effective intervention† | 21 | 0.14 (−0.08 to 0.37) | 0.34 (0.22 to 0.46) | 52 (20 to 71) | 0.003 |
| Other | 23 | 0.31 (0.07 to 0.54) | 0.27 (0.12 to 0.42) | 42 (4 to 64) | 0.02 |
| Significant biomarker effect: | |||||
| Yes | 27 | 0.22 (0.05 to 0.39) | 0.33 (0.23 to 0.43) | 45 (14 to 65) | 0.006 |
| No | 4 | 1.19 (−0.48 to 2.86) | 1.19 (−0.48 to 2.86) | 0 (0 to 85) | 0.901 |
| Biomarker recommended for clinical use: | |||||
| Yes | 16 | 0.22 (−0.01 to 0.45) | 0.26 (0.12 to 0.39) | 55 (20 to 74) | 0.005 |
| No | 15 | 0.43 (0.28 to 0.58) | 0.43 (0.28 to 0.58) | 0 (0 to 54) | 0.502 |
*The difference in biomarker effects between datasets from observational studies and from randomised controlled trials as a proportion of the summary effect of each meta-analysis.
†Refers to trials showing significant difference between treatment arms for cardiovascular disease end points and populations of both arms were considered in analysis of the biomarker.