. Author manuscript; available in PMC: 2019 Jul 1.

Published in final edited form as: Aliment Pharmacol Ther. 2018 May 30;48(2):127–137. doi: 10.1111/apt.14823

Table 4.

Quality assessment of studies by checklist

Author Year	Representative cohort	Ascertainment of exposure	Outcome not present at start	Assessment of outcome	Sufficient follow-up period	Adequacy of follow-up
Bielen 2017¹⁶	^*	^*	High	High	^*	High
Cabibbo 2017¹⁷	^*	^*	^*	^*	High	Unknown
Ikeda 2017¹⁸	^*	^*	Medium	Medium	^*	^*
Ngata 2017¹⁹	^*	^*	High	Medium	^*	Unknown
Ogawa 2017²⁰	^*	^*	^*	^*	^*	Unknown
Reig 2017²¹	^*	^*	^*	Medium	High	^*
Virlogeux 2017²²	^*	^*	^*	Medium	^*	High
Conti 2016²³	^*	^*	Medium	Medium	High	^*
ANRS 2016²⁴	^*	^*	Medium	High	^*	Unknown
ANRS 2016²⁴	^*	^*	Medium	High	^*	Unknown
Rinaldi 2016²⁵	^*	^*	^*	Medium	High	Unknown
Zavaglia 2017²⁶	^*	^*	^*	High	High	High
Zeng 2016²⁷	^*	^*	High	Medium	^*	^*
Torres 2016²⁸	^*	^*	Medium	^*	High	Unknown
Gheoghe 2017²⁹	^*	^*	Medium	High	High	Unknown
Granata 2017³⁰	^*	^*	^*	^*	^*	Unknown
Kolly 2017³¹	^*	^*	High	High	^*	Unknown
Yasui 2017³²	High	^*	High	High	High	Unknown
Minami 2017³³	^*	^*	Medium	High	^*	High
Ohki 2017³⁴	^*	^*	High	High	^*	Unknown
Sangiovanni 2017³⁵	^*	^*	Medium	^*	High	High
Singal 2017³⁷	^*	^*	Medium	High	^*	Unknown
Urabe 2017³⁶	^*	^*	Medium	High	High	Unknown
Tokoro 2016³⁸	^*	^*	High	Medium	^*	Unknown
Tsuda 2016³⁹	^*	^*	Medium	High	High	Unknown

High = high risk of bias; Medium = intermediate risk of bias;

= low risk of bias