Table 3.
Conversion of DerSimonian-Laird results into Hartung-Knapp-Sidik-Jonkman results for a continuous outcome: severity of cold symptoms
|
DerSimonian and Laird results |
Calculations for Hartung-Knapp- Sidik-Jonkman
|
|||
|---|---|---|---|---|
| Study | Study results SMD y i | Weights w i | (y i –y) 2 | w i × (y i –y) 2 |
| Kurugol 2006a |
−0.04 |
24.0 |
0.1225 |
2.94 |
| Kurugol 2007 |
−0.07 |
22.2 |
0.1024 |
2.27 |
| Petrus 1998 |
−0.31 |
21.3 |
0.0064 |
0.14 |
| Prasad 2000 |
−1.36 |
15.5 |
0.9409 |
14.58 |
| Prasad 2008 |
−0.54 |
17.0 |
0.0225 |
0.38 |
| |
y = −0.39 |
Sum: 100.0 |
|
Sum: 20.31 |
| 5 studies, I2 = 75.0%, τ2 = 0.13 | ||||
| DL pooled result [95% CI]: SMD = −0.39 [−0.77, –0.02]; z = 2.05; P–value = 0.04 | ||||
| HKSJ pooled result [95% CI]: SMD = −0.39 [−1.02, 0.24]; t = 1.73; P–value = 0.16 (df = 4) | ||||
SMD: Standardized mean difference. DL: DerSimonian & Laird meta-analysis method. HKSJ: Hartung-Knapp-Sidik-Jonkman meta-analysis method. CI: Confidence Interval, df: degrees of freedom, ×: multiplication sign. The pooled effect y and the weights wi originate from the DL random-effects analysis.