Table 3.
Summary of results for binary outcomes showing tests of heterogeneity and the variation in OR and RR attributable to heterogeneity (I2) for the following subgroups in the meta-analysis: 1) Subthreshold ADHD vs. Controls, and 2) Subthreshold ADHD vs. Full ADHD.
| Subthreshold ADHD vs. Controls | ||||
|---|---|---|---|---|
| Study | Heterogeneity Statistic | Degrees of Freedom | p | I2 |
| Scahill 1999 | 0.0 | 1 | 0.9 | 0.0% |
| Kadesjö 2001 | 5.0 | 6 | 0.5 | 0.0% |
| Lewinsohn 2004 | 9.2 | 15 | 0.9 | 0.0% |
| Bussing 2010 | 85.2 | 19 | <0.01 | 77.7% |
| Fergusson 2010 | 12.3 | 5 | 0.03 | 59.5% |
| Selinus 2016 | 43.6 | 6 | <0.01 | 86.2% |
| Biederman 2018 | 61.1 | 11 | <0.01 | 82.0% |
| Overall | 556.4 | 69 | <0.01 | 87.6% |
| Subthreshold ADHD vs Full ADHD | ||||
| Scahill 1999 | 2.2 | 1 | 0.14 | 53.6% |
| Kadesjö 2001 | 8.9 | 6 | 0.18 | 32.5% |
| Lewinsohn 2004 | 12.6 | 6 | 0.05 | 52.3% |
| Cho 2009* | 7.9 | 12 | 0.80 | 0.0% |
| Bussing 2010 | 61.3 | 19 | <0.01 | 69.0% |
| Fergusson 2010 | 33.7 | 5 | <0.01 | 85.1% |
| Selinus 2016 | 1.8 | 6 | 0.94 | 0.0% |
| Biederman 2018 | 39.5 | 11 | <0.01 | 72.2% |
| Overall | 251.0 | 73 | <0.01 | 70.9% |
*
Cho 2009 did not report data on controls for the extracted outcome variables and therefore is only included in the Subthreshold ADHD vs. Full ADHD subgroup meta-analysis.