What does an odds ratio (OR) of 1.5 indicate regarding ASA intake and heart disease?

An odds ratio (OR) of 1.5 indicates that individuals who use aspirin (ASA) have 1.5 times the odds of developing heart disease compared to those who do not use aspirin. This means there is a clear association between ASA intake and heart disease, suggesting that ASA users are at a higher risk of developing heart disease than non-users.

In epidemiological studies, an OR of 1 suggests no difference in odds between the groups being compared, while an OR greater than 1 indicates an increased risk. Therefore, an OR of 1.5 specifically denotes that there is a statistically significant increase in the odds of heart disease associated with ASA use. The concept of "1.5 times" is relative to the baseline risk, thus reinforcing the interpretation that ASA intake correlates with elevated risk rather than a decrease or neutrality in risk.