1. Summary of test accuracy at study level by dementia prevalence.

Study	Included participants (n)	Dementia n (%)	AD‐8 Threshold	Sensitivity (%)	Specificity (%)
Galvin 2006	241	217 (90)	2	92	46
Galvin 2006	241	217 (90)	3	89	67
Razavi 2014	186	129 (69)	2	99	74
Jackson 2016	77	47 (61)	3	98	40
Larner 2015	212	69 (33)	2	97	11
Galvin 2007	324	73 (23)	2	84	93
Galvin 2007	324	73 (23)	3	75	90
Yang 2016	2015	444 (22)	2	90	78
Correia 2011	109	15 (14)	2	73	61
Correia 2011	109	15 (14)	3	100	67
Chan 2016	309	44 (14)	3	91	91
Meguro 2015	572	69 (12)	2	88	68
Where multiple thresholds were reported in the primary paper, we present the data for both a cut‐off score of 2 and 3. The total number of participants is adjusted to reflect the data used in quantitative synthesis.