This Is Why with Dr. Busti

Independent vs paired study groups explained and how they determine the correct statistical test in clinical research. In this This Is Why lecture, Dr. Busti breaks down one of the most important steps in biostatistics—identifying the type of study groups and how that directly impacts statistical test selection. Understanding whether groups are independent or related is essential for interpreting...

Parkinson disease medication discontinuation safety is the focus of this episode of This Is Why with Dr. Busti. In this board-style practice question, we work through a clinical scenario involving adverse effects, medication management, and the reasoning process needed to approach discontinuation decisions safely in practice and on exams. In this episode, Dr. Busti breaks down how to think through...

Types of data for a study's endpoint are explained—nominal, ordinal, or continuous—and how each determines the appropriate statistical test in clinical research. In this lecture on This Is Why, Dr. Busti walks through one of the most critical steps in biostatistics: correctly identifying the type of data based on the study question. This is where many learners make mistakes—especially when di...

How do you choose the right statistical test in clinical research? In this This Is Why (TIW) lecture, Dr. Busti introduces the biostatistics decision-making framework that connects hypothesis, study design, and data type to the correct statistical analysis. This is not a memorization lecture—it’s about understanding the structure behind statistical choices so you can evaluate research correctly as...

What is dyspnea, and why does it matter in clinical practice? In this episode of This Is Why, Dr. Busti breaks down the medical term dyspnea—commonly described as shortness of breath—and explain how healthcare professionals should think about it beyond simple definitions. Dyspnea should not be solely considered a diagnosis. It is a symptom that requires clinical reasoning. So the question becomes:...

Internal and external validity are foundational to interpreting clinical research and applying evidence in practice. In this This Is Why lecture, Dr. Busti explains how validity is established, what threatens it, and how clinicians should evaluate it during critical appraisal. This lecture is part of the This Is Why (TIW) evidence-based medicine series, helping clinicians connect study design to r...

Types of bias in research and their impact on results are critical to understanding study design, internal validity, and clinical decision-making. In this lecture on This Is Why, Dr. Busti walks through how bias is introduced, how it affects results, and how clinicians should interpret it. This lecture is part of the This Is Why evidence-based medicine (EBM) series, designed to help clinicians con...

Picking the right benzodiazepine based on its metabolism is a critical concept for understanding medication safety, especially when considering hepatic function and drug accumulation. In this episode of This Is Why, Dr. Busti walks through a board-style practice question to break down how different metabolic pathways impact clinical decision-making. This case highlights how pharmacokinetics direct...

Hypothesis testing is a core concept in biostatistics and evidence-based medicine. In this This Is Why lecture, Dr. Busti explains how hypotheses guide clinical research design and how clinicians interpret statistical results in medical literature. Understanding hypothesis testing helps clinicians determine whether study findings represent true differences or random chance. In this lecture, we bre...

The ultimate guide to types of study designs used in clinical research is explained and made easy for clinicians and researchers. In this lecture on This Is Why, Dr. Busti walks through the major study designs used in medical research and explains how each design affects bias, causality, and the interpretation of clinical evidence. Dr. Busti also addresses the pros and cons of major study designs...

Clinical research design and the NIH clinical research process are explained for clinicians. In this This Is Why lecture, Dr. Busti introduces the foundations of clinical epidemiology, biostatistics, and clinical literature evaluation while walking through the NIH framework for how clinical research studies are designed and conducted. Understanding how clinical research is developed—from the origi...

CHA₂DS₂-VASc score atrial fibrillation is a critical concept for determining when anticoagulation is recommended. In this episode of This Is Why with Dr. Busti, we break down a board-style clinical question to explain when anticoagulation should NOT be started in atrial fibrillation. Understanding stroke risk stratification is essential for USMLE, NAPLEX, NP, PA, and medical board exams. This epis...

What is proctalgia fugax, and why does this term matter in real clinical practice? In this episode of This Is Why, Dr. Busti breaks down the meaning of proctalgia fugax, its etymology, how it has been understood historically, and how healthcare professionals should use the term today. This lesson focuses on concept-based learning, helping clinicians connect the terminology to differential diagnosi...

In this lecture from This is Why, Dr. Busti will explain the COPD maintenance inhalers you’ll actually see in practice. In this pharmacology review, we break down LAMA (long-acting muscarinic antagonist) bronchodilators—one of the most important bronchodilator classes for COPD treatment—so you can confidently understand the drugs, the mechanism, and the real-world clinical use. You’ll learn how to...

Short-acting muscarinic antagonists (SAMAs) are a core bronchodilator drug class you’ll see constantly in COPD care. In this lecture from This is Why, Dr. Busti will learn about short-acting muscarinic antagonists (SAMAs) are a core bronchodilator drug class you’ll see constantly in COPD care—and on exams like the NCLEX. In this lecture, you’ll learn exactly how SAMAs work, when to use them, and w...

Understand the GLP-1 receptor agonists—and why agents like semaglutide (Ozempic/Wegovy/Rybelsus), liraglutide, dulaglutide, and exenatide have become one of the most talked-about type 2 diabetes medications in modern practice. In this lecture from This is Why, Dr. Busti will break GLP-1s down in a clear, clinically relevant way so you can confidently explain how they work, when to use them, and wh...

Insulin doesn’t have to be confusing when learning how to treat Type 1 and Type 2 diabetes mellitus. In this lecture from This is Why, Dr. Busti will explain how to quickly recognize insulin types, predict onset/peak/duration, and apply basal–bolus dosing concepts to real-world Type 1 and Type 2 diabetes care. You’ll learn how to: - How to identify rapid-, short-, intermediate-, and long-acting in...

Meglitinides (Nateglinide & Repaglinide) can feel like the “forgotten” oral diabetes drugs—but they show up on exams, in real-world medication histories, and in questions about postprandial glucose control and hypoglycemia and weight gain risk. In this lecture from This is Why, Dr. Busti will explain the meglitinides in a clear, clinically relevant way so you can recognize them quickly and use...

SGLT2 inhibitors (bexagliflozin, canagliflozin, dapagliflozin, empagliflozin, ertugliflozin) don’t just lower glucose and A1C, but these meds have become relevant in cardiovascular disease and chronic kidney disease in the right patients also with type 2 diabetes (T2DM). In this lecture from This is Why, Dr. Busti will make the SGLT2 inhibitors make sense as they provide cardiorenal protection abo...

Dr. Busti covers one of the most-tested Type 2 diabetes drug classes—sulfonylureas. If you’ve ever mixed up glyburide vs glipizide, worried about hypoglycemia, or wanted a clear “when do I pick this?” framework, this drug class review is for you. In this lecture from This is Why, Dr. Busti will break down Sulfonylureas (Glyburide, Glipizide) step-by-step so you can confidently in the context of tr...

In this lecture from This is Why, Dr. Busti will break down pioglitazone and the thiazolidinediones (TZDs) so you can confidently explain the mechanism, clinical use, side effects, and key contraindications for type 2 diabetes (T2DM). You’ll learn how to: - TZDs (pioglitazone): where they fit in type 2 diabetes (T2DM) therapy - Mechanism of action: PPAR-γ agonist → increased insulin sensitivity (m...

In this lecture from This is Why, Dr. Busti will explain how Long-Acting Beta Agonists (LABAs) work, where they fit in therapy for the management of asthma and COPD. You’ll learn how to: - Mechanism of action: beta-2 receptor activation → bronchodilation (airway smooth muscle relaxation) - Clinical use: LABAs in COPD maintenance vs asthma (must be combined with ICS) - Onset/duration differences an...

In this lecture from This is Why, Dr. Busti will break down SABA (Short-Acting Beta Agonist) bronchodilators, like albuterol, for the acute management of asthma symptoms and COPD flare-ups. You’ll learn how to: - What SABAs are and when they’re used (rescue vs controller) - Beta-2 agonist mechanism of action (bronchodilation and smooth muscle effects) - How fast albuterol works, typical duration,...

In this lecture from This is Why, Dr. Busti will teach you about Alpha-Glucosidase Inhibitors for Diabetes — the pharmacology made easy breakdown of acarbose and miglitol for type 2 diabetes. You’ll learn how to: - Explain how alpha-glucosidase inhibitors reduce postprandial hyperglycemia - Identify where these drugs work (GI tract) and why they don’t cause hypoglycemia by themselves - Compare aca...

Amylin Analogs (Pramlintide) for Diabetes: Pharmacology Made Easy.  In this lecture from This is Why, Dr. Busti will explain how pramlintide (Symlin/SymlinPen) works and when it’s used as an adjunct to insulin for type 1 diabetes (and select type 2 diabetes cases). In this diabetes pharmacology review, I break down the mechanism of action of an amylin analog, why it helps postprandial glucose cont...