Table 1.

Risk of bias assessment of included studies according to the modified Newcastle-Ottawa Scale—Version for cohort studies (n = 11)

Quality assessment	APS studies					SLE studies	NPSLE studies
	Arvanitakis et al. (2019) [20]	Homayoon et al. (2014) [21]	Zamproni et al. (2013) [22]	Erkan et al. (2010) [23]	Chapman et al. (2002) [24]	Whitelaw et al. (1999) [25]	Sarbu et al. (2015) [26]	Steup-Beekman et al. (2013) [27]	Abda et al. (2013) [28]		Zirkzee et al. (2012) [29]	Cantú-Brito et al. (2010) [30]
Selection
1. Is the case definition adequate	●	●	●	●	○	○	●	●	●	●		●
2. Representativeness of cases	●	●	●	○	○	○	●	○	●	○		○
3. Ascertainment of exposure	●	●	●	●	●	●	●	●	●	●		●
4. Outcome of interest was not present at start of study	●	●	○	●	●	●	●	●	○	○		●
Comparability
5. Study controls for most important factor	●	●	○	●	○	○	●	○	○	○		○
6. Study controls for second important factor	●	●	○	●	○	○	●	○	○	○		○
Outcome
7. Assessment of outcome	●	●●	●●	●●	●●	●●	●●	●●	●●	●●		●
8. Statistical test (CS only)		●	●	○	○	●	●	○	●	●		●
9. Adequate follow up period for outcome of interest (LS only)	●
10. Adequacy of follow up of cohorts (LS only)	●											●
Total score	9/9	9/9	6/9	7/9	4/9	5/9	9/9	5/9	6/9	5/9		6/9

CS: cross-sectional studies; LS: longitudinal studies.