A study enrolls 200 T2DM pts with HbA1c >8%. Pts are randomized to receive either a new oral hypoglycemic agent (OHA) or a placebo. The study is double-blinded, and the primary outcome is the change in HbA1c after 6 months. Which of the following best describes this study design?

A junior resident is preparing a journal club on the efficacy of a new oral anticoagulant. To form a definitive conclusion, she must base her presentation on the most robust form of medical evidence available. Which study design represents the highest level of evidence?

A public health program aims to ↓ the long-term incidence of COPD and IHD by tracking the prevalence of a key behavior in adults >18 Y/O. If the program's primary metric is the percentage of adults who smoke, how is this indicator best classified?

In a study on maternal smoking and childhood asthma, the exposed cohort (children of smokers) undergoes more frequent asthma workups due to higher parental vigilance for respiratory symptoms. This results in a higher reported incidence of asthma in the exposed group. This finding is most likely distorted by which type of bias?

A new biomarker assay (Sens 99%, Spec 99.5%) for a rare disease (Prevalence 1/50,000) is used for population screening. A 45 Y/O asymptomatic M tests positive. Which performance metric is most substantially decreased when applying this test to a low-prevalence population?

A clinical trial compares a novel immunotherapy vs. standard chemo in metastatic NSCLC. The primary outcome is the patient's functional status, measured by the ordinal ECOG performance scale (0-5). What is the most appropriate statistical test to compare the ECOG scores between the two groups?

A clinical trial on a new drug for liver failure reports 'days to recovery.' The data is right-skewed with the following results: Mean = 18 days, Median = 9 days, Mode = 7 days. You are counseling a patient's family on the expected timeline. Which value is most appropriate to communicate as the typical recovery time?

A lab compares two cortisol assays. Assay A reports in nmol/L (mean 450, SD 90). Assay B reports in µg/dL (mean 16, SD 4). A clinician needs to compare their relative variability to assess consistency. Most appropriate statistical measure to use?

A study measures fasting blood glucose (FBG) in 30 patients with T2DM at baseline and again in the same 30 patients after 8 weeks of a new Rx. The goal is to compare the mean FBG before and after the intervention. Which statistical test is most appropriate for this analysis?