Phase I - "Is it Safe?" * Purpose: Safety, toxicity, pharmacokinetics, pharmacodynamics * Participants: Small number of healthy volunteers (or patients with the disease if drug is toxic, e.g., chemo) * 20-80 (1 zero) * Key Point: First-in-human → assess safe dosage range and side effects Phase II - "Does it

Primary prevention Primary prevention strategies aim to prevent the effects of a disease before the disease occurs. * HPV vaccination to prevent cervical cancer. * Lifestyle counseling to reduce risk of diabetes (e.g., promoting exercise and a healthy diet). * Water fluoridation to prevent dental caries. Secondary prevention Secondary prevention strategies aimed

PPV/NPV * Given a positive test result, what is the probability that the patient actually has the disease? * \(PPV = \frac{\text{true positives (TP)}}{\text{TP} + \text{false positives (FP)}}\) * \(NPV = \frac{\text{true negative (TN)}}{\text{TN} + \text{false negatives(FN)}}\) Positive/negative likelihood ratio * \(\text{Positive likelyhood ratio}

Case control * Risk factors * Odds ratio * \(\text{Odds Ratio} = \frac{\text{Odds of cases}}{\text{Odds of controls}}\) * Rare diseases * Start with disease (case) and no disease (control) -> What caused this (exposure)? * "Case-control" = "Cases Come First" (You start with cases, then go backward to