Comparison 3. Parent‐rated ADHD symptoms.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
3.1 All parallel‐group trials and first‐period cross‐over trials	27	2927	Std. Mean Difference (IV, Random, 95% CI)	‐0.63 [‐0.76, ‐0.50]
3.1.1 Low risk of bias	6	702	Std. Mean Difference (IV, Random, 95% CI)	‐0.49 [‐0.71, ‐0.26]
3.1.2 High risk of bias	21	2225	Std. Mean Difference (IV, Random, 95% CI)	‐0.66 [‐0.81, ‐0.51]
3.2 Subgroup analysis: types of scales	27		Std. Mean Difference (IV, Random, 95% CI)	Subtotals only
3.2.1 Conners' Parent Rating Scale (CPRS)	8	800	Std. Mean Difference (IV, Random, 95% CI)	‐0.53 [‐0.80, ‐0.26]
3.2.2 ADHD Rating Scale ‐ Fourth Edition (ADHD‐RS‐IV)	5	753	Std. Mean Difference (IV, Random, 95% CI)	‐0.37 [‐0.53, ‐0.21]
3.2.3 Fremdbeurteilungsbogen für Hyperkinetische Störungen (FBB‐HKS)	1	85	Std. Mean Difference (IV, Random, 95% CI)	‐0.91 [‐1.36, ‐0.46]
3.2.4 Conners’ ADHD/DSM‐IV Scales ‐ Parent (CADS‐P)	2	195	Std. Mean Difference (IV, Random, 95% CI)	‐1.12 [‐1.44, ‐0.81]
3.2.5 CADS‐P Inattentive subscale	1	109	Std. Mean Difference (IV, Random, 95% CI)	‐0.78 [‐1.17, ‐0.39]
3.2.6 CADS‐P Hyperactivity subscale	1	109	Std. Mean Difference (IV, Random, 95% CI)	‐0.93 [‐1.32, ‐0.53]
3.2.7 Clinican's Manual for the Assesment of Disruptive Behavior Disorders Rating Scale for Parents (Barkley)	1	41	Std. Mean Difference (IV, Random, 95% CI)	‐0.21 [‐0.82, 0.41]
3.2.8 Abbreviated Conners' Rating Scale (ACRS) ‐ Parent	2	121	Std. Mean Difference (IV, Random, 95% CI)	‐0.62 [‐0.99, ‐0.25]
3.2.9 Swanson, Nolan, and Pelham, Fourth Edition ‐ Parent (SNAP‐IV‐Parent) Scale	4	390	Std. Mean Difference (IV, Random, 95% CI)	‐0.59 [‐0.80, ‐0.39]
3.2.10 Strengths and Weaknesses of ADHD Symptoms and Normal Behavior (SWAN) Scale	1	86	Std. Mean Difference (IV, Random, 95% CI)	‐0.43 [‐0.86, 0.00]
3.2.11 IOWA Conners' Rating Scale ‐ Inattention/Overactivity (IOWA‐I/O)	3	352	Std. Mean Difference (IV, Random, 95% CI)	‐0.78 [‐1.35, ‐0.21]
3.2.12 Parent Vanderbilt ADHD Rating Scale	1	97	Std. Mean Difference (IV, Random, 95% CI)	‐0.67 [‐1.23, ‐0.11]
3.3 Subgroup analysis: duration of treatment	27	2927	Std. Mean Difference (IV, Random, 95% CI)	‐0.63 [‐0.76, ‐0.50]
3.3.1 Short term (up to 6 months)	25	2605	Std. Mean Difference (IV, Random, 95% CI)	‐0.63 [‐0.78, ‐0.49]
3.3.2 Long term (over 6 months)	2	322	Std. Mean Difference (IV, Random, 95% CI)	‐0.56 [‐0.79, ‐0.34]
3.4 Subgroup analysis: dose	27	3075	Std. Mean Difference (IV, Random, 95% CI)	‐0.61 [‐0.74, ‐0.48]
3.4.1 Low dose	4	254	Std. Mean Difference (IV, Random, 95% CI)	‐0.51 [‐1.14, 0.13]
3.4.2 High dose	12	1650	Std. Mean Difference (IV, Random, 95% CI)	‐0.58 [‐0.80, ‐0.37]
3.4.3 Unknown dose	13	1171	Std. Mean Difference (IV, Random, 95% CI)	‐0.67 [‐0.83, ‐0.51]
3.5 Subgroup analysis: medication status ‐ medication naive versus not medication naive	11	992	Std. Mean Difference (IV, Random, 95% CI)	‐0.65 [‐0.87, ‐0.43]
3.5.1 Medication naive	7	544	Std. Mean Difference (IV, Random, 95% CI)	‐0.58 [‐0.84, ‐0.32]
3.5.2 Not medication naive	4	448	Std. Mean Difference (IV, Random, 95% CI)	‐0.75 [‐1.16, ‐0.35]
3.6 Subgroup analysis: trials with enrichment design compared with trials without enrichment design	25	2803	Std. Mean Difference (IV, Random, 95% CI)	‐0.63 [‐0.77, ‐0.49]
3.6.1 Trials with enrichment design of all participants	13	2155	Std. Mean Difference (IV, Random, 95% CI)	‐0.63 [‐0.78, ‐0.48]
3.6.2 Trials without enrichment design of all participants	12	648	Std. Mean Difference (IV, Random, 95% CI)	‐0.61 [‐0.88, ‐0.34]
3.7 Subgroup analysis: parallel‐group trials compared with first‐period cross‐over trials	27	2927	Std. Mean Difference (IV, Random, 95% CI)	‐0.63 [‐0.76, ‐0.50]
3.7.1 Parallel‐group trials	25	2874	Std. Mean Difference (IV, Random, 95% CI)	‐0.62 [‐0.76, ‐0.49]
3.7.2 First‐period cross‐over trials	2	53	Std. Mean Difference (IV, Random, 95% CI)	‐0.68 [‐1.25, ‐0.11]
3.8 Subgroup analysis: type of control group	27	2927	Std. Mean Difference (IV, Random, 95% CI)	‐0.63 [‐0.76, ‐0.50]
3.8.1 Placebo control group	19	2263	Std. Mean Difference (IV, Random, 95% CI)	‐0.64 [‐0.80, ‐0.48]
3.8.2 No‐intervention control group	8	664	Std. Mean Difference (IV, Random, 95% CI)	‐0.59 [‐0.84, ‐0.34]
3.9 Cross‐over trials (endpoint data)	45	4971	Std. Mean Difference (IV, Random, 95% CI)	‐0.70 [‐0.86, ‐0.55]
3.9.1 Low risk of bias	8	853	Std. Mean Difference (IV, Random, 95% CI)	‐0.56 [‐0.72, ‐0.40]
3.9.2 High risk of bias	37	4118	Std. Mean Difference (IV, Random, 95% CI)	‐0.75 [‐0.94, ‐0.57]
3.10 Subgroup analysis: cross‐over trials (endpoint data): dose	45	6155	Std. Mean Difference (IV, Random, 95% CI)	‐0.63 [‐0.76, ‐0.50]
3.10.1 Low dose	26	3242	Std. Mean Difference (IV, Random, 95% CI)	‐0.58 [‐0.71, ‐0.45]
3.10.2 High dose	29	2508	Std. Mean Difference (IV, Random, 95% CI)	‐0.75 [‐0.90, ‐0.60]
3.10.3 Unknown dose	3	405	Std. Mean Difference (IV, Random, 95% CI)	0.19 [‐1.55, 1.93]
3.11 Subgroup analysis: all parallel‐group trials and first‐period cross‐over trials compared with cross‐over trials (endpoint data)	69	7838	Std. Mean Difference (IV, Random, 95% CI)	‐0.67 [‐0.78, ‐0.56]
3.11.1 All parallel‐group trials and first‐period cross‐over trials	27	2955	Std. Mean Difference (IV, Random, 95% CI)	‐0.63 [‐0.76, ‐0.50]
3.11.2 Cross‐over trials (endpoint data)	43	4883	Std. Mean Difference (IV, Random, 95% CI)	‐0.71 [‐0.86, ‐0.55]
3.12 All parallel‐group trials and cross‐over trials: risk of bias	69	7503	Std. Mean Difference (IV, Random, 95% CI)	‐0.68 [‐0.79, ‐0.57]
3.12.1 Low risk of bias	12	1234	Std. Mean Difference (IV, Random, 95% CI)	‐0.53 [‐0.68, ‐0.39]
3.12.2 High risk of bias	57	6269	Std. Mean Difference (IV, Random, 95% CI)	‐0.71 [‐0.84, ‐0.58]
3.13 All parallel‐group trials and cross‐over trials: vested interest	69	7503	Std. Mean Difference (IV, Random, 95% CI)	‐0.68 [‐0.79, ‐0.57]
3.13.1 Low risk of vested interest	19	1187	Std. Mean Difference (IV, Random, 95% CI)	‐0.69 [‐0.84, ‐0.54]
3.13.2 High risk or unclear risk of vested interest	50	6316	Std. Mean Difference (IV, Random, 95% CI)	‐0.68 [‐0.82, ‐0.54]