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Measurement & Interpretation
How to interpret tests, biomarkers, and measurements responsibly. Emphasizes context, limitations, and common sources of misinterpretation.
Entries in this topic
Absolute Risk vs Relative Risk: How Headlines Mislead
A drug reducing cancer from 2% to 1% shows a 50% relative risk reduction—mathematically true but misleading. Absolute risk reduction (1%) better reflects rea...
Evidence Methodology & Research Literacy9 min readEditor's pickJul 2025
Animal Models in Gut Research: Mice Are Not Tiny Humans
Germ-free and humanised mice reveal mechanisms but differ fundamentally from humans; ~90% translation failure from animals to clinical trials.
Evidence Methodology & Research Literacy7 min readAug 2025
Biomarkers of Inflammation: CRP, Calprotectin, and Beyond
What clinicians measure when they assess inflammation — and why no single biomarker tells the whole story.
Biomarkers & Diagnostic Methods9 min readEditor's pickOct 2025
Bradford Hill Criteria: Judging Causation From Association
Nine criteria help judge whether associations reflect causation: strength, consistency, specificity, temporality, biological gradient, plausibility, coherenc...
Evidence Methodology & Research Literacy11 min readApr 2025
Breath Testing: What It Can and Cannot Tell You
How hydrogen and methane breath tests work for SIBO and carbohydrate malabsorption — and why interpretation requires clinical context.
Biomarkers & Diagnostic Methods9 min readEditor's pickMay 2025
Cherry-Picking Data: How Studies Can Prove Anything
Selective outcome reporting, data dredging, and subgroup fishing allow researchers to find p < 0.05 for almost any hypothesis. Pre-registration and pre-speci...
Evidence Methodology & Research Literacy10 min readJun 2025
Cochrane Reviews: The Benchmark for Evidence-Based Medicine
Cochrane Collaboration conducts pre-registered, transparent, high-quality systematic reviews using GRADE assessment; living reviews update evidence as new tr...
Evidence Methodology & Research Literacy7 min readEditor's pickAug 2025
Confidence Intervals: What the Error Bars Really Mean
A 95% confidence interval is the plausible range of true effect values. If the interval crosses zero (or 1.0 for odds ratios), the effect is not statisticall...
Evidence Methodology & Research Literacy9 min readAug 2025
Conflicts of Interest in Nutrition Research
Industry funding pervasively shapes nutrition research. Coca-Cola, sugar lobby, and dairy interests funded studies minimizing harm. Disclosing funding is nec...
Evidence Methodology & Research Literacy9 min readEditor's pickSep 2025
Confounding Variables: The Hidden Third Factor
Ice cream consumption correlates with drowning deaths—but both increase in summer. Heat is the confounder. Healthy-user bias distorts supplement studies; tho...
Evidence Methodology & Research Literacy9 min readOct 2025
Effect Size: The Statistic That Matters More Than P-Values
Cohen's d measures effect magnitude; p-values only test significance. A probiotic reducing bloating 0.2 points on 10-point scale (p=0.04) is statistically si...
Evidence Methodology & Research Literacy10 min readJun 2025
False Positives and Negatives: Why Tests Can Mislead
How sensitivity, specificity, and pre-test probability interact to determine the real meaning of a test result — and why 'positive' doesn't always mean disease.
Biomarkers & Diagnostic Methods8 min readEditor's pickOct 2025
Fecal Calprotectin: What Your Stool Test Really Measures
How calprotectin works as a neutrophil-derived marker, what elevated levels indicate, and where the test falls short.
Biomarkers & Diagnostic Methods7 min readEditor's pickMay 2025
Forest Plots Explained: Reading a Meta-Analysis Chart
Forest plots visualize study results and their combined effect in meta-analyses, revealing heterogeneity and study weight at a glance.
Evidence Methodology & Research Literacy8 min readMay 2025
GRADE Framework: How Guideline Panels Rate Evidence Quality
GRADE is a systematic framework for rating evidence quality and recommendation strength, guiding clinical decision-making.
Evidence Methodology & Research Literacy9 min readEditor's pickSep 2025
Human Clinical Trials: Phases, Endpoints, and What 'Significant' Means
RCTs progress through phases testing safety and efficacy; surrogate endpoints predict clinical benefit imperfectly; statistical significance differs from cli...
Evidence Methodology & Research Literacy7 min readSep 2025
In Vitro Studies: What Petri Dishes Can and Cannot Tell Us
Cell culture studies provide mechanistic insight but lack immune, hormonal, and neural context; organoids improve but remain reductionist.
Evidence Methodology & Research Literacy7 min readAug 2025
Interpreting Stool Tests: A Patient's Guide
What different stool tests measure, how to read your results, and why context determines meaning.
Biomarkers & Diagnostic Methods8 min readEditor's pickJul 2025
Microbiome-Based Diagnostics: Promise and Pitfalls
How machine learning is being applied to microbial signatures for disease detection — and why we're not ready for clinical use.
Biomarkers & Diagnostic Methods9 min readJul 2025
Number Needed to Treat: The Most Useful Stat You've Never Heard Of
NNT tells you how many patients to treat to prevent one bad outcome. For antibiotics in UTI, NNT ≈ 2 (highly beneficial); for statins in primary prevention, ...
Evidence Methodology & Research Literacy10 min readAug 2025
Observational vs Interventional Studies: Correlation Is Not Causation
Observational studies (cohort, case-control) reveal associations; interventional studies (RCTs) establish causation; reverse causation and confounding plague...
Evidence Methodology & Research Literacy7 min readJul 2025
P-Hacking and HARKing: How Statistics Get Tortured
P-hacking means trying multiple analyses until p < 0.05 emerges. HARKing (Hypothesizing After Results are Known) involves retroactively labeling findings as ...
Evidence Methodology & Research Literacy10 min readSep 2025
P-Values Explained: What p < 0.05 Actually Means
{"type": "root", "children": [{"type": "paragraph", "children": [{"type": "text", "value": "A p-value measures the probability of observing your data if the ...
Evidence Methodology & Research Literacy8 min readDec 2025
Pre-Prints and Peer Review: How Science Self-Corrects
Traditional peer review delays publication; pre-print servers accelerate dissemination; COVID-19 demonstrated pre-print value and risks; post-publication pee...
Evidence Methodology & Research Literacy7 min readJul 2025
Publication Bias: The File Drawer Problem
Journals preferentially publish positive findings; negative results languish unpublished. This creates a false consensus favoring treatments. Rosenthal's fil...
Evidence Methodology & Research Literacy10 min readEditor's pickJul 2025
Randomised Controlled Trials: The Gold Standard and Its Limits
Randomisation, blinding, and allocation concealment eliminate bias; yet short duration, cost constraints, and ethical limits restrict what trials can investi...
Evidence Methodology & Research Literacy7 min readEditor's pickAug 2025
Reading Blood Test Results for Gut Health
What your full blood count, iron studies, CRP, liver function, and coeliac serology actually tell your doctor about your gut.
Biomarkers & Diagnostic Methods9 min readEditor's pickSep 2025
Sample Size Matters: Why Small Studies Deceive
Small studies suffer from the 'law of small numbers'—random variation produces exaggerated effects, and underpowered studies miss real effects. Microbiome re...
Evidence Methodology & Research Literacy9 min readMay 2025
Statistical Significance vs Clinical Significance: The Crucial Difference
A statistically significant finding can be clinically worthless if the effect is tiny. Real-world impact matters more than p-values when deciding whether a t...
Evidence Methodology & Research Literacy9 min readMay 2025
Surrogate Endpoints: When Lab Values Don't Equal Health
Surrogate endpoints measure biomarkers (CRP, cholesterol, diversity) but don't always predict health outcomes. HRT increased bone density (surrogate) yet inc...
Evidence Methodology & Research Literacy9 min readApr 2025
Survivorship Bias in Health Research
Surviving subjects look healthier than the true population, distorting research findings. Healthy elderly people in cohort studies survived into old age part...
Evidence Methodology & Research Literacy10 min readSep 2025
Systematic Reviews and Meta-Analyses: Combining the Evidence
Systematic reviews synthesise evidence following PRISMA guidelines; meta-analyses statistically combine results, detecting heterogeneity and publication bias.
Evidence Methodology & Research Literacy7 min readJul 2025
The Hierarchy of Evidence: From Case Reports to Meta-Analyses
Evidence hierarchies rank study designs from anecdotal case reports to systematic reviews; GRADE provides modern contextual framework replacing rigid pyramids.
Evidence Methodology & Research Literacy7 min readJun 2025
The Replication Crisis: Why Many Studies Don't Hold Up
Open Science Collaboration found 36% of psychology studies replicate; Begley & Ellis found 11% of preclinical cancer studies replicate. Causes: low power, an...
Evidence Methodology & Research Literacy10 min readEditor's pickJun 2025
Translational Research: From Bench to Bedside to Population
Translational research bridges basic science and clinical practice through three phases; most discoveries never reach patients despite promising preclinical ...
Evidence Methodology & Research Literacy7 min readApr 2025
Zonulin and Intestinal Permeability: Science vs Hype
What zonulin actually is, what it measures, and why 'leaky gut' testing requires critical interpretation.
Gut Barrier & Epithelial Integrity9 min readSep 2025