. 2021 Nov 24;20:15330338211043784. doi: 10.1177/15330338211043784

Table 7.

Quality Assessments of Retrospective Research.

Author	Selection	Comparability	Exposure	Score
HONG NO²¹	⋆⋆⋆⋆	⋆⋆	⋆⋆⋆	9
Steffensen²⁴	⋆⋆⋆	⋆⋆	⋆⋆⋆	8
Parkinson⁴	⋆⋆⋆	⋆⋆	⋆⋆⋆	8
Meng²⁰	⋆⋆	⋆⋆	⋆⋆⋆	7
Steffensen²³	⋆⋆⋆	⋆⋆	⋆⋆⋆	8