Intention-to-Treat (ITT) vs Modified ITT (mITT) vs Per Protocol (PP) vs As Treated (AT) vs Complier Average Causal Effect (CACE): Choosing the Right Analysis in Clinical Trials
Strategy Core Logic Maintains Randomization? Bias Profile Best Use Case Intention-to-Treat (ITT) Analyze everyone as randomized ,...
Immortal Time Bias Explained: Time-Dependent Exposure vs Landmark Analysis
Introduction Immortal time bias arises when a period of time during which an individual must survive (i.e., cannot experience the...
Internal vs External Validation in Clinical Prediction Models: Split-Sampling, Cross-Validation, Bootstrapping, Temporal, Geographic, Domain
🎯 WHY VALIDATION? When building a Clinical Prediction Model (CPM) , the biggest trap is overestimating its true performance . This...
Calibration and Clinical Utility in Prediction Models: Intercept, Slope & DCA Explained
Evaluating a prediction model requires more than assessing discrimination. Calibration and clinical usefulness determine whether a model is both statistically trustworthy and clinically actionable . This article explores: Calibration Intercept Calibration Slope Mechanistic Interpretation (e.g., overprediction) Calibration Plot Decision Curve Analysis (DCA) 🧭 1. Calibration Intercept: Is the Average Prediction Biased? Definition: The calibration intercept compares the aver
How to Evaluate Clinical Prediction Models (CPMs): Discrimination, Calibration, Overall Performance, Clinical Utility, and Validation
Introduction Clinical prediction models (CPMs)—whether prognostic or diagnostic—must be rigorously appraised before implementation in...
Case-Crossover vs Case-Control: Choosing the Right Causal Design
🎯 Context: DEPTh Classification = Etiologic (Causal) Challenge Both designs ask: Does exposure X cause outcome Y? But their logic...
What Is Prognostic Research? PROGRESS I: Overall Prognosis Research, PROGRESS II: Prognostic Factor Research, PROGRESS III: Prognostic Model Research, PROGRESS IV: Stratified Medicine Research
What Is Prognostic Research? Prognostic research aims to understand what is likely to happen to a patient after diagnosis . Unlike...
3 subtypes of analogous cross-sectional membership recruitment of Diagnostic Accuracy Research: Balanced vs. Imbalanced Index and Reference Test Results in Diagnostic Accuracy Research
Cross-Sectional Nature of Diagnostic Research Diagnostic accuracy research is cross-sectional by nature — predictors (index test) and...
What Is a Systematic Search? And Check Keyword validation and Noise
🔍 Definition: What Is a Systematic Search? A systematic search is a methodologically rigorous, comprehensive, and transparent process...
IV Fluids in Pancreatitis: Why Acute Needs It and Chronic Doesn’t
1. Acute Pancreatitis: Why IV Hydration Is Essential Pathophysiology Acute pancreatic inflammation → release of inflammatory mediators →...
Acute and Chronic Pancreatitis: Diagnosis and Management Essentials
I. Acute Pancreatitis 1. Diagnosis Based on Revised Atlanta Criteria (2012) — diagnosis requires ≥2 of 3 : Typical abdominal pain :...
Bias in Randomized Controlled Trials: Understanding Selection, Performance, Detection, and Attrition Bias
Bias Type Dimension Explanation Selection Bias External Validity Evaluate inclusion/exclusion criteria —do they represent the target...
Containers and Kubernetes Explained: From Takeaway Boxes to Cloud Scalability
1. Introduction Modern applications need to run reliably across different environments: laptops, servers, or cloud platforms. This is...
Synkinesis Syndromes: When Nerves Misfire After Injury
Abstract Peripheral and cranial nerve injuries may paradoxically lead not only to functional deficits but also to aberrant reinnervation....
Chikungunya Fever: Diagnosis, Differentials, and Management Guidelines
1. 👁️🗨️ Signs & Symptoms (Clinical Presentation) System Findings Systemic High-grade fever (acute onset), chills Musculoskeletal...
Hordeolum (Stye): Diagnosis, Management & Referral Guidelines
✅ Diagnosis Criteria A clinical diagnosis based on history and physical examination . 🔍 Diagnostic Features: Feature Description Onset...
Allopurinol in Gout: When to Start, How to Dose, and When to Stop
Introduction If you’ve ever treated or studied gout , you’ve met allopurinol — the go-to urate-lowering therapy (ULT) that changes the game for patients plagued by painful flares. But knowing when to start it, how to adjust it, and if ever to stop it is a nuanced skill — and it’s something both clinicians and medical students need to master. Let’s break it down in a way that’s practical for clinical life and exam prep. What Is Allopurinol? Allopurinol is a xanthine oxidas
Hepatitis B Vaccination: Indications, Antibody Titers, and Non-Responder Management
1. Who Should Receive the Hepatitis B Vaccine Universal vaccination is recommended by CDC, WHO, and Thai MOPH: A. Infants Birth dose...
Seasonal Allergic Rhinitis: Diagnosis and Management
Definition Seasonal allergic rhinitis (SAR) is an IgE-mediated inflammation of the nasal mucosa triggered by airborne allergens present...
Cellulitis & Erysipelas: Diagnosis, Severity Grading, and Management
1. Diagnosis Definitions Cellulitis : Acute infection involving deep dermis and subcutaneous tissue . Erysipelas : Acute infection...
P-Values in Regression: Beyond Thresholds—A Clinical-Grade Guide
1. What is a p -value in Regression, Really? A p -value tests how surprising your observed association (e.g., between age and systolic...
Modeling Repeated Measures in Clinical Research: Fixed and Random Effects Explained
Introduction In clinical research, data are frequently collected from the same individuals at multiple time points. These repeated...
Choosing the Right Regression Model in Clinical Research: A Practical Guide
Introduction Regression models form the cornerstone of modern clinical and epidemiologic analysis. Whether the aim is to understand risk...