Comparison 1. An arm support together with an alternative mouse versus a conventional mouse alone.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Neck/shoulder discomfort score at 12‐month follow‐up	2	194	Std. Mean Difference (IV, Random, 95% CI)	‐0.41 [‐0.69, ‐0.12]
2 Incidence of neck/shoulder disorder at 12‐month follow‐up	2	186	Risk Ratio (M‐H, Random, 95% CI)	0.52 [0.27, 0.99]
3 Right upper extremity discomfort score at 12‐month follow‐up	2	194	Std. Mean Difference (IV, Random, 95% CI)	‐0.34 [‐0.63, ‐0.06]
4 Incidence of right upper limb disorder at 12‐month follow‐up	2	181	Risk Ratio (M‐H, Random, 95% CI)	0.73 [0.32, 1.66]
5 Incidence of upper body disorders (neck, shoulder, and upper limb) at 12‐month follow‐up	2	191	Risk Ratio (M‐H, Random, 95% CI)	0.66 [0.42, 1.04]
6 Change in percentage of work time	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
7 Change in average time to completely process a call	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
8 Change in calls per hour	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
9 Subject perceived improvement	1		Odds Ratio (M‐H, Fixed, 95% CI)	Totals not selected