Statistics and Interpretation of Evidence

Canonical Reading Material for the Exam Candidate
Oh's Intensive Care manual: Chapter 10 (pp. 75) Clinical trials in critical care by Simon Finfer and Anthony Delaney. Particularly, Table 10.3 on page 90 is something one should commit to memory. JAMA's User's Guide to the Medical Literature is linked to by www.hopkinsmedicine.org; I have also linked to the specific articles here. However, JAMA makes you pay for most of them. CASP (Critical Appraisal Skills Program) has checklists for the appraisal of many different sorts of studies; these actually come with tickboxes. One imagines reviewers wandering around a trial headquarters, ticking these boxes on their little clipboards. CEBM (Centre for Evidence Based Medicine) also has checklists, which (in my opinion) are more informative. Here is a link to their checklist for the critical appraisal of an RCT. Summaries and discussions of statistics and EBM from Life in the Fast Lane are made available as a list of links in the Resources section.

Basic Concepts in Medical Statistics
Definition and relevance of evidence based medicine
Basic features of evidence-based medicine
Quality and levels of evidence
Levels of evidence and grading the quality of recommendations
Types of studies, their advantages and disadvantages
A short list of statistics equations
A short list of definitions for the lazy exam candidate

Instruments of Statistical Analysis
Precision of findings: p-value and the confidence interval
Propensity score analysis
Qualitative data: Chi-square test and Fisher's Exact Test
Quantitative data: measures of variability and central tendency
Statistical tests for quantitative data
Data distributions
Measures of effect size, risk and odds
Measures of test accuracy: sensitivity specificity and predictive value

Clinical Trial Design
Stages in the design of a clinical trial
Advantages and disadvantages of randomised control study design
Factors which influence sample size calculation
Statistical power
Non-inferiority trials
Platform trials
Bias, types of error and confounding factors
Steps in designing and conducting a clinical trial
Randomisation
Blinding
Intention to treat analysis
Subgroup analysis
Outcome measures
Study power, population and sample size
Statistical significance and clinical significance

Error and Bias in Medical Research
Types of error in medical research
Types of bias in medical research
Confounding in clinical trials
Interpretive bias

Types of Data and Statistical Tests
Basic definitions in statistics
Different types of data
Variability, dispersion and central tendency
Parametric and non-parametric tests
The forest plot and the box-and-whisker plot
The receiver operating characteristic (ROC) curve

Interpretation of Evidence into Practice
The meaninglessness of published evidence
Meta-analysis and systematic review
Critical appraisal of clinical trials
Critical appraisal of meta-analysis data
Interpretation of time-to-event curves
Trials which stop earlier than expected

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© Alex Yartsev
2013-2022