Non-traditional risk factors for myocardial infarction in adults under forty: A systematic review of emerging trends

Table 5 Risk of bias assessment

Study ID	Study design	Quality tool	Score	Quality classification	Key limitations
1	Cohort	NOS	7	High	Administrative data, coding errors
2	Cohort	NOS	7	High	Residual confounding, observational design
3	Cohort	NOS	6	Moderate	Retrospective data, potential selection bias
4	Case-control	NOS	5	Moderate	Small sample size, cross-sectional design
5	Cohort	NOS	8	High	Limited exposure detail
6	Cohort	NOS	7	High	Short follow-up, single center
7	Cohort	NOS	7	High	Potential residual confounding
8	Case-control	NOS	6	Moderate	Recall bias, dietary assessment
9	Case-control	NOS	5	Moderate	Small sample, self-reported exposures
10	Cross-sectional	AHRQ	7	Moderate	Self-report, cross-sectional design
11	Cross-sectional	AHRQ	6	Moderate	Surrogate outcome, autopsy data
12	Case-control	NOS	7	High	Potential selection bias
13	Cohort	NOS	5	Moderate	Retrospective design, limited non-traditional risk data

NOS: Not otherwise specified; AHRQ: Agency for healthcare research and quality.