Comparison 1. Splint versus no treatment.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Short‐term overall improvement (3 months or less)	1	80	Risk Ratio (M‐H, Fixed, 95% CI)	3.86 [2.29, 6.51]
1.1 At 4 weeks	1	80	Risk Ratio (M‐H, Fixed, 95% CI)	3.86 [2.29, 6.51]
2 Adverse effects	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
2.1 Difficulty in falling asleep	1	80	Risk Ratio (M‐H, Fixed, 95% CI)	7.0 [0.37, 131.28]
2.2 Transient paraesthesias	1	80	Risk Ratio (M‐H, Fixed, 95% CI)	9.0 [0.50, 161.86]
3 Short‐term improvement in CTS symptoms (Levine questionnaire) (3 months or less)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
3.1 At 4 weeks	1	80	Mean Difference (IV, Random, 95% CI)	‐1.07 [‐1.29, ‐0.85]
3.2 At 12 weeks	1	48	Mean Difference (IV, Random, 95% CI)	‐0.94 [‐1.10, ‐0.78]
3.3 At the end of 6 months treatment	1	34	Mean Difference (IV, Random, 95% CI)	‐0.90 [‐1.11, ‐0.69]
4 Short‐term improvement in CTS symptoms (pressure‐provocative test time) (3 months or less)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
4.1 At 12 weeks	1	48	Mean Difference (IV, Fixed, 95% CI)	0.04 [‐5.31, 5.39]
4.2 At end of 6 months treatment	1	34	Mean Difference (IV, Fixed, 95% CI)	8.25 [2.49, 14.01]
5 Short‐term improvement in CTS symptoms (Phalen test time) (3 months or less)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
5.1 At 12 weeks	1	48	Mean Difference (IV, Fixed, 95% CI)	2.74 [‐3.32, 8.80]
5.2 At the end of 6 months treatment	1	34	Mean Difference (IV, Fixed, 95% CI)	6.20 [‐1.44, 13.84]
6 Short‐term improvement in functional status (Levine questionnaire) (3 months or less)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
6.1 At 4 weeks	1	80	Mean Difference (IV, Random, 95% CI)	‐0.55 [‐0.82, ‐0.28]
6.2 At 12 weeks	1	48	Mean Difference (IV, Random, 95% CI)	‐0.22 [‐0.40, ‐0.04]
6.3 At the end of 6 months treatment	1	34	Mean Difference (IV, Random, 95% CI)	‐0.25 [‐0.68, 0.18]
7 Short‐term improvement in distal motor latency (ms) (3 months or less)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
7.1 At 4 weeks	1	80	Mean Difference (IV, Random, 95% CI)	‐0.02 [‐0.49, 0.45]
7.2 At 12 weeks	1	48	Mean Difference (IV, Random, 95% CI)	‐0.26 [‐0.57, 0.05]
7.3 At the end of 6 months treatment	1	34	Mean Difference (IV, Random, 95% CI)	0.08 [‐0.23, 0.39]
8 Short‐term improvement in sensory nerve conduction velocity (m/s) (3 months or less)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
8.1 At 4 weeks	1	80	Mean Difference (IV, Random, 95% CI)	‐0.72 [‐5.85, 4.41]
8.2 At 12 weeks	1	48	Mean Difference (IV, Random, 95% CI)	5.13 [1.21, 9.05]
8.3 At the end of 6 months treatment	1	34	Mean Difference (IV, Random, 95% CI)	1.41 [‐2.22, 5.04]
9 Short‐term improvement in sensory nerve action potential (uV) (3 months or less)	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
9.1 At 4 weeks	1	80	Mean Difference (IV, Random, 95% CI)	6.30 [0.60, 12.00]
9.2 At 12 weeks	1	48	Mean Difference (IV, Random, 95% CI)	‐1.34 [‐6.27, 3.59]
9.3 At the end of 6 months treatment	1	34	Mean Difference (IV, Random, 95% CI)	‐0.86 [‐7.17, 5.45]
10 Short‐term improvement in distal sensory latency (ms) (3 months or less)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
10.1 At 12 weeks	1	48	Mean Difference (IV, Fixed, 95% CI)	‐0.26 [‐0.47, ‐0.05]
10.2 At the end of 6 months treatment	1	34	Mean Difference (IV, Fixed, 95% CI)	‐0.10 [‐0.37, 0.17]
11 Short‐term improvement in motor nerve conduction velocity (m/s) (3 months or less)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
11.1 At 12 weeks	1	48	Mean Difference (IV, Fixed, 95% CI)	2.97 [0.83, 5.11]
11.2 At the end of 6 months treatment	1	34	Mean Difference (IV, Fixed, 95% CI)	1.70 [‐1.17, 4.57]
12 Short‐term improvement in motor nerve action potential (mV) (3 months or less)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
12.1 At 12 weeks	1	48	Mean Difference (IV, Fixed, 95% CI)	‐2.21 [‐4.47, 0.05]
12.2 At the end of 6 months treatment	1	34	Mean Difference (IV, Fixed, 95% CI)	1.85 [‐0.49, 4.19]