Correlation between non-alcoholic fatty liver disease and erectile dysfunction: A systematic narrative review

Table 2 Quality assessment of the studies included in the systematic review

Ref.	Study design	Assessment tools	Assessment results	Interpretation of results
Tarik Kani et al[3], 2021	Retrospective study	NOS	7 stars	The maximum total score is nine stars. A score of seven or more stars generally indicates high-quality research, while a score of five or six stars indicates medium quality, and a score of less than five stars indicates low quality
Youcheng et al[10], 2025	Prospective study	NOS	6 stars
Duman et al[11], 2016	Retrospective study	NOS	6 stars
Yilmaz et al[12], 2021	Prospective study	NOS	7 stars
Eren and Horsanali[13], 2019	Cross-sectional study	AHRQ	8 points	This standard comprises 11 items, each of which is answered with “Yes”, “No”, or “Uncertain”. A “Yes” response earns 1 point. A total score of 0-3 indicates low quality, 4-7 indicates medium quality, and 8-11 indicates high quality
Hasanain et al[14], 2017	Cross-sectional study	AHRQ	7 points
Ragab et al[15], 2024	Observational study	AHRQ	6 points

NOS: Newcastle-Ottawa Scale; AHRQ: Agency for Healthcare Research and Quality.