The article does not discuss whether the study adjusted for confounding factors such as alcohol consumption, obesity, diabetes, or socioeconomic status, which are known risk factors for liver disease.
Observational studies like this one cannot establish causality, only association. For example, coffee drinkers might have other healthy habits contributing to lower liver disease risk.
The article lacks details on the study’s methodology, such as how coffee consumption was measured (self-reported vs. objective) or whether dose-response relationships were analyzed beyond the 3–4 cup threshold.
The claim of a 49% reduction in mortality from chronic liver disease is significant but requires scrutiny, as such a large effect size could be influenced by unmeasured variables or biases.