Table 1.

Main characteristics of studies (n = 13) included in the systematic review

Study	Country	Study type	Sample				Type of stroke
			MS stroke +	MS total	Control stroke +	Control stroke	All-cause stroke	AIS	ICH
Allen et al. 2008 [18]	USA	Registry	178	9949	268	19,898	+	+	+
Christiansen et al. 2010 [19]	Denmark	Cohort	38	13,963	49	66,407	+	+
Lavela et al. 2012 [20]	USA	Cohort	80	1142	957	68,357	+
Zöller et al. 2012 [21]	Sweden	Registry	88	10,384			+	+	+
Jadidi et al. 2013 [22]	Sweden	Registry	194	7664	728	66,214	+
Tseng et al. 2014 [23]	Taiwan	Cohort	41	1174	44	4696	+	+
Capcun et al. 2015 [24]	USA	Cohort	1880	15,684	2812	78,420	+	+	+
Thorman et al. 2016 [25]	Denmark	Registry	565	8947	1677	44,735	+
Persson et al. 2017 [26]	UK/USA	Registry	88	12,132	456	123,612	+	+
Zulfiqar et al. 2018 [27]	Mexico	Cohort	107	57,099			+
Castelo-Branco et al. 2020 [28]	Sweden	Cohort	159	6602	518	61,828	+	+
Tadic et al. 2020 [29]	Bosnia and Herzegovina	Cohort	1	100	2	50	+
Cho et al. 2022 [30]	South Korea	Cohort	86	1541	171	7705	+	+	+

Abbreviations: MS: multiple sclerosis; AIS: acute ischaemic attack; ICH: intracerebral haemorrhage