When exploring a topic, you will often come across many different studies with varying findings. Rather than relying on a single study, it is important to look at the wider body of evidence and identify overall patterns.
Our website provides summaries of research exploring links between coffee and various health and wellbeing topics. These are intended to support interpretation of the overall evidence, drawing on findings from robust research and different study designs, and aiming to feature the highest quality research available.
But what makes a study strong, credible and reliable? Below are some of the key factors to consider when evaluating scientific research.
A credible study involves enough participants to ensure the findings are scientifically meaningful. Studies with larger sample sizes reduce the likelihood that results happened by chance and help ensure outcomes represent a broader population. However, there is no set ‘golden’ sample size, as this will differ depending on factors, such as the research area, study design and methodology.
Strong research is typically published in peerreviewed journals, where an expert panel of independent reviewers has assessed the study’s methodology and robustness of the conclusions drawn.
Reputable journals usually have transparent peer review processes, an editorial board of relevant experts and quality standards designed to ensure scientific rigour. Metrics such as impact factor may also provide useful context.
Evidence evolves over time, with more recent studies reflecting the latest evidence. However, older research can still be valuable, especially in areas where there have been fewer new studies.
While laboratory (invitro) or animal studies are valuable for early insights, human research provides the most directly relevant evidence for understanding realworld health effects.
Good research clearly describes the study objective, design, participant selection, methods, measurements, statistical analyses, study limitations, and potential sources of bias, allowing the reliability and relevance of the findings to be properly assessed. Reliable studies also try to limit the effects of external factors (known as “confounders”) that could influence results, helping ensure any observed effect is more directly linked to the subject being studied.
See study design for more details.
A single study rarely provides definitive answers but can make a strong contribution to existing evidence bases. Research is most credible where it aligns with multiple other studies showing similar results and can be repeated. This consistency helps build scientific credibility and consensus over time.
Systematic reviews and meta-analyses are often prioritised, as they combine findings from multiple studies to provide a more comprehensive picture of evidence.
See study design for more details.
