Table 2.

Quality of included studies assessed with Newcastle Ottawa scale (n = 16).

Study	Number of stars awarded in each domain			Total score (out of 9)
	Selection (Maximum: 4★)	Comparability (Maximum: 2★)	Outcome (Maximum: 3★)
Alonso-Ferndez 202020	★★★★	★★	★★	8
Benito 202021	★★★★	★★	★★	8
Bilaloglu 202022	★★	★	★★	5
Bompard 202023	★★	★	★★★	6
Chen 202024	★★★★	★★	★★★	9
Contou 202025	★★★★	★★	★★	8
Fauvel 202026	★★★★	★★	★★	8
Gervaise 202027	★★★★	★★	★★★	9
Grillet 202028	★★	★★	★	5
Leord-Lorant 202029	★★	–	★★	4
Mestre-Gómez 202030	★★★★	★	★★★	8
Mouhat 202031	★★★★	★★	★★★	9
Soumagne 202035	★★	★★	★★	6
Taccone 202032	★★	★★	★★	6
Ventura-Díaz 202033	★★★★	★★	★★★	9
Whyte 202034	★★★★	★	★★	7

A maximum of four, three, and two stars were assigned to the Selection, Comparability, and Outcome domains, respectively. The higher the number of stars, the better the quality of the study (i.e., up to nine stars for highest quality studies). For the second item of the Outcome domain, we awarded one star to a study if the patients were discharged from hospital or succumbed to the disease. For non-hospitalised patients or lack of relevant information (e.g., discharge or fatality) for inpatients, no star was assigned with the assumption of inadequate follow-up. One star was given to the last item of the Outcome domain for (1) studies with a follow-up rate ≥ 80%, or (2) those with a follow-up rate < 80% but including a description of lack of significant difference in demographic characteristics between the follow-up and lost-to-follow-up groups.