Table 7.

Short-term memory: Hedge’s g effect sizes for each test, in descending order.

Test name	N studies	N CFS	N controls	Hedges'g	S.E	95% CI	p value	Q	p	I2 (%)	Study references
Visual modality
Spatial span forward	2	71	40	− 0.55	0.20	− 0.952 to − 0.151	0.007	2.03	0.15	50.64	Joyce et al.29, Robinson et al.44
Spatial working memory (between search errors)	2	101	157	0.26	0.13	0.012–0.514	0.04	0.00	0.94	0.00	Capuron et al.13, Majer et al.33
Spatial working memory (strategy score)	2	101	157	0.36	0.13	0.105–0.609	0.006	3.28	0.07	69.50	Capuron et al.13, Majer et al.33
Verbal modality
Digit span backward	8	251	195	− 0.37	0.10	− 0.566 to − 0.182	0.0001	24.50	0.00	71.43	De Luca et al.22, Fiedler et al.24, Lawrie et al.31, Michiels et al.39, Neu et al.42, Robinson et al.44, Tiersky et al.52, Vercoulen et al.54
Digit span forward	11	359	261	− 0.23	0.08	− 0.387 to − 0.064	0.006	7.64	0.66	0.00	Claypoole et al.15, De Luca et al.22, Fiedler et al.24, Lawrie et al.31, Marcel et al.34, Michiels et al.39, Neu et al.42, Robinson et al.44, Smith et al.51, Tiersky et al.52, Vercoulen et al.54

ME/CFS myalgic encephalomyelitis/chronic fatigue syndrome, N number.