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. 2023 Mar 27;2023(3):CD009885. doi: 10.1002/14651858.CD009885.pub3

Comparison 2. Independent assessor‐rated ADHD symptoms.

Outcome or subgroup title No. of studies No. of participants Statistical method Effect size
2.1 All parallel‐group trials and first‐period cross‐over trials 22 3724 Std. Mean Difference (IV, Random, 95% CI) ‐1.10 [‐1.44, ‐0.77]
2.1.1 Low risk of bias 4 942 Std. Mean Difference (IV, Random, 95% CI) ‐0.40 [‐0.78, ‐0.03]
2.1.2 High risk of bias 18 2782 Std. Mean Difference (IV, Random, 95% CI) ‐1.30 [‐1.70, ‐0.89]
2.2 Subgroup analysis: types of scales 22   Std. Mean Difference (IV, Random, 95% CI) Subtotals only
2.2.1 Swanson, Kotkin, Agler, M‐Glynn and Pelham (SKAMP) Scale 6 778 Std. Mean Difference (IV, Random, 95% CI) ‐2.79 [‐4.10, ‐1.47]
2.2.2 ADHD Rating Scale (ADHD‐RS ) 14 2802 Std. Mean Difference (IV, Random, 95% CI) ‐0.60 [‐0.81, ‐0.38]
2.2.3 Swanson, Nolan and Pelham (SNAP) Scale 1 221 Std. Mean Difference (IV, Random, 95% CI) ‐0.35 [‐0.61, ‐0.08]
2.2.4 Unknown 1 78 Std. Mean Difference (IV, Random, 95% CI) ‐0.94 [‐1.41, ‐0.47]
2.3 Subgroup analysis: duration of treatment 22 3724 Std. Mean Difference (IV, Random, 95% CI) ‐1.10 [‐1.44, ‐0.77]
2.3.1 Short term (up to 6 months) 21 3503 Std. Mean Difference (IV, Random, 95% CI) ‐1.15 [‐1.50, ‐0.80]
2.3.2 Long term (over 6 months) 1 221 Std. Mean Difference (IV, Random, 95% CI) ‐0.35 [‐0.61, ‐0.08]
2.4 Subgroup analysis: dose 22 3724 Std. Mean Difference (IV, Random, 95% CI) ‐1.10 [‐1.44, ‐0.77]
2.4.1 Low dose 1 138 Std. Mean Difference (IV, Random, 95% CI) ‐0.19 [‐0.52, 0.15]
2.4.2 High dose 17 3005 Std. Mean Difference (IV, Random, 95% CI) ‐0.84 [‐1.13, ‐0.55]
2.4.3 Unknown dose 4 581 Std. Mean Difference (IV, Random, 95% CI) ‐2.57 [‐4.40, ‐0.74]
2.5 Subgroup analysis: trials with enrichment design compared with trials without enrichment design 22 3724 Std. Mean Difference (IV, Random, 95% CI) ‐1.10 [‐1.44, ‐0.77]
2.5.1 Trials with enrichment design of all participants 19 3245 Std. Mean Difference (IV, Random, 95% CI) ‐1.24 [‐1.61, ‐0.87]
2.5.2 Trials without enrichment design of all participants 3 479 Std. Mean Difference (IV, Random, 95% CI) ‐0.22 [‐0.62, 0.17]
2.6 Subgroup analysis: type of control group 22 3724 Std. Mean Difference (IV, Random, 95% CI) ‐1.10 [‐1.44, ‐0.77]
2.6.1 Placebo control group 20 3200 Std. Mean Difference (IV, Random, 95% CI) ‐1.22 [‐1.58, ‐0.85]
2.6.2 No‐intervention control group 2 524 Std. Mean Difference (IV, Random, 95% CI) ‐0.14 [‐0.52, 0.23]
2.7 Subgroup analysis: parallel‐group trials compared with first‐period cross‐over trials 22 3724 Std. Mean Difference (IV, Random, 95% CI) ‐1.10 [‐1.44, ‐0.77]
2.7.1 Parallel‐group trials 19 3550 Std. Mean Difference (IV, Random, 95% CI) ‐1.17 [‐1.54, ‐0.80]
2.7.2 First‐period cross‐over trials 3 174 Std. Mean Difference (IV, Random, 95% CI) ‐0.72 [‐1.03, ‐0.41]
2.8 Cross‐over trials (endpoint data) 22 3854 Std. Mean Difference (IV, Random, 95% CI) ‐0.97 [‐1.11, ‐0.83]
2.8.1 High risk of bias 22 3854 Std. Mean Difference (IV, Random, 95% CI) ‐0.97 [‐1.11, ‐0.83]
2.9 Subgroup analysis: cross‐over trials (endpoint data): dose 22 5257 Std. Mean Difference (IV, Random, 95% CI) ‐0.88 [‐1.00, ‐0.76]
2.9.1 Low dose 17 3067 Std. Mean Difference (IV, Random, 95% CI) ‐0.72 [‐0.86, ‐0.58]
2.9.2 High dose 13 2051 Std. Mean Difference (IV, Random, 95% CI) ‐1.07 [‐1.27, ‐0.86]
2.9.3 Unknown dose 1 139 Std. Mean Difference (IV, Random, 95% CI) ‐1.03 [‐1.39, ‐0.68]
2.10 Subgroup analysis: all parallel‐group trials and first‐period cross‐over trials compared with cross‐over trials (endpoint data) 42 7277 Std. Mean Difference (IV, Random, 95% CI) ‐0.99 [‐1.18, ‐0.80]
2.10.1 All parallel‐group trials and first‐period cross‐over trials 21 3586 Std. Mean Difference (IV, Random, 95% CI) ‐1.15 [‐1.50, ‐0.81]
2.10.2 Cross‐over trials (endpoint data) 21 3691 Std. Mean Difference (IV, Random, 95% CI) ‐0.93 [‐1.07, ‐0.78]
2.11 All parallel‐group trials and cross‐over trials: risk of bias 42 7277 Std. Mean Difference (IV, Random, 95% CI) ‐0.99 [‐1.18, ‐0.80]
2.11.1 Low risk of bias 4 942 Std. Mean Difference (IV, Random, 95% CI) ‐0.40 [‐0.78, ‐0.03]
2.11.2 High risk of bias 38 6335 Std. Mean Difference (IV, Random, 95% CI) ‐1.06 [‐1.25, ‐0.86]
2.12 All parallel‐group trials and cross‐over trials: vested interest 43 7414 Std. Mean Difference (IV, Random, 95% CI) ‐0.98 [‐1.17, ‐0.80]
2.12.1 Low risk of vested interest 6 600 Std. Mean Difference (IV, Random, 95% CI) ‐0.96 [‐1.43, ‐0.48]
2.12.2 High risk or unclear risk of vested interest 37 6814 Std. Mean Difference (IV, Random, 95% CI) ‐0.99 [‐1.19, ‐0.79]