Description
Efnisyfirlit
- Cover
- Also available to buy!
- Preface
- Part 1 Handling data
- 1 Types of data
- Data and statistics
- Categorical (qualitative) data
- Numerical (quantitative) data
- Distinguishing between data types
- Derived data
- Censored data
- 2 Data entry
- Formats for data entry
- Planning data entry
- Categorical data
- Numerical data
- Multiple forms per patient
- Problems with dates and times
- Coding missing values
- 3 Error checking and outliers
- Typing errors
- Error checking
- Handling missing data
- Outliers
- References
- 4 Displaying data diagrammatically
- One variable
- Two variables
- Identifying outliers using graphical methods
- The use of connecting lines in diagrams
- 5 Describing data: the ‘average’
- Summarizing data
- The arithmetic mean
- The median
- The mode
- The geometric mean
- The weighted mean
- 6 Describing data: the ‘spread’
- Summarizing data
- The range
- Ranges derived from percentiles
- The standard deviation
- Variation within- and between-subjects
- 7 Theoretical distributions: the Normal distribution
- Understanding probability
- The rules of probability
- Probability distributions: the theory
- The Normal (Gaussian) distribution
- The Standard Normal distribution
- 8 Theoretical distributions: other distributions
- Some words of comfort
- More continuous probability distributions
- Discrete probability distributions
- 9 Transformations
- Why transform?
- How do we transform?
- Typical transformations
- Part 2 Sampling and estimation
- 10 Sampling and sampling distributions
- Why do we sample?
- Obtaining a representative sample
- Point estimates
- Sampling variation
- Sampling distribution of the mean
- Interpreting standard errors
- SD or SEM?
- Sampling distribution of the proportion
- 11 Confidence intervals
- Confidence interval for the mean
- Confidence interval for the proportion
- Interpretation of confidence intervals
- Degrees of freedom
- Bootstrapping and jackknifing
- Reference
- Part 3 Study design
- 12 Study design I
- Experimental or observational studies
- Defining the unit of observation
- Multicentre studies
- Assessing causality
- Cross-sectional or longitudinal studies
- Controls
- Bias
- Reference
- 13 Study design II
- Variation
- Replication
- Sample size
- Particular study designs
- Choosing an appropriate study endpoint
- References
- 14 Clinical trials
- Treatment comparisons
- Primary and secondary endpoints
- Subgroup analyses
- Treatment allocation
- Sequential trials
- Blinding or masking
- Patient issues
- The protocol
- References
- 15 Cohort studies
- Selection of cohorts
- Follow-up of individuals
- Information on outcomes and exposures
- Analysis of cohort studies
- Advantages of cohort studies
- Disadvantages of cohort studies
- Study management
- Clinical cohorts
- 16 Case–control studies
- Selection of cases
- Selection of controls
- Identification of risk factors
- Matching
- Analysis of unmatched or group-matched case–control studies
- Analysis of individually matched case–control studies
- Advantages of case–control studies
- Disadvantages of case–control studies
- References
- Part 4 Hypothesis testing
- 17 Hypothesis testing
- Defining the null and alternative hypotheses
- Obtaining the test statistic
- Obtaining the P-value
- Using the P-value
- Non-parametric tests
- Which test?
- Hypothesis tests versus confidence intervals
- Equivalence and non-inferiority trials
- References
- 18 Errors in hypothesis testing
- Making a decision
- Making the wrong decision
- Power and related factors
- Multiple hypothesis testing
- References
- Part 5 Basic techniques for analysing data
- 19 Numerical data: a single group
- The problem
- The one-sample t-test
- The sign test
- 20 Numerical data: two related groups
- The problem
- The paired t-test
- The Wilcoxon signed ranks test
- Reference
- 21 Numerical data: two unrelated groups
- The problem
- The unpaired (two-sample) t-test
- The Wilcoxon rank sum (two-sample) test
- Reference
- 22 Numerical data: more than two groups
- The problem
- One-way analysis of variance
- The Kruskal–Wallis test
- References
- 23 Categorical data: a single proportion
- The problem
- The test of a single proportion
- The sign test applied to a proportion
- 24 Categorical data: two proportions
- The problems
- Independent groups: the Chi-squared test
- Related groups: McNemar’s test
- Reference
- 25 Categorical data: more than two categories
- Chi-squared test: large contingency tables
- Chi-squared test for trend
- 26 Correlation
- Pearson correlation coefficient
- Spearman’s rank correlation coefficient
- 27 The theory of linear regression
- What is linear regression?
- The regression line
- Method of least squares
- Assumptions
- Analysis of variance table
- Regression to the mean
- 28 Performing a linear regression analysis
- The linear regression line
- Drawing the line
- Checking the assumptions
- Failure to satisfy the assumptions
- Outliers and influential points
- Assessing goodness of fit
- Investigating the slope
- Using the line for prediction
- Improving the interpretation of the model
- 29 Multiple linear regression
- What is it?
- Why do it?
- Assumptions
- Categorical explanatory variables
- Analysis of covariance
- Choice of explanatory variables
- Analysis
- Outliers and influential points
- Reference
- 30 Binary outcomes and logistic regression
- Reasoning
- The logistic regression equation
- The explanatory variables
- Assessing the adequacy of the model
- Comparing the odds ratio and the relative risk
- Multinomial and ordinal logistic regression
- Conditional logistic regression
- References
- 31 Rates and Poisson regression
- Rates
- Poisson regression
- 32 Generalized linear models
- Which type of model do we choose?
- Likelihood and maximum likelihood estimation
- Assessing adequacy of fit
- Regression diagnostics
- 33 Explanatory variables in statistical models
- Nominal explanatory variables
- Ordinal explanatory variables
- Numerical explanatory variables
- Selecting explanatory variables
- Interaction
- Collinearity
- Confounding
- 34 Bias and confounding
- Bias
- Confounding
- References
- 35 Checking assumptions
- Why bother?
- Are the data Normally distributed?
- Are two or more variances equal?
- Are variables linearly related?
- What if the assumptions are not satisfied?
- Sensitivity analysis
- References
- 36 Sample size calculations
- The importance of sample size
- Requirements
- Methodology
- Altman’s nomogram
- Quick formulae
- Power statement
- Adjustments
- Increasing the power for a fixed sample size
- References
- 37 Presenting results
- Numerical results
- Tables
- Diagrams
- Presenting results in a paper
- References
- Part 6 Additional chapters
- 38 Diagnostic tools
- Reference intervals
- Diagnostic tests
- 39 Assessing agreement
- Measurement variability and error
- Reliability
- Categorical variables
- Numerical variables
- Reporting guidelines
- References
- 40 Evidence-based medicine
- 1 Formulate the clinical question (PICO)
- 2 Locate the relevant information (e.g. on diagnosis, prognosis or therapy)
- 3 Critically appraise the methods in order to assess the validity (closeness to the truth) of the evidence
- 4 Extract the most useful results and determine whether they are important
- 5 Apply the results in clinical practice
- 6 Evaluate your performance
- References
- 41 Methods for clustered data
- Displaying the data
- Comparing groups: inappropriate analyses
- Comparing groups: appropriate analyses
- Reference
- 42 Regression methods for clustered data
- Aggregate level analysis
- Robust standard errors
- Random effects models
- Generalized estimating equations (GEE)
- References
- 43 Systematic reviews and meta-analysis
- The systematic review
- Meta-analysis
- References
- 44 Survival analysis
- Censored data
- Displaying survival data
- Summarizing survival
- Comparing survival
- Problems encountered in survival analysis
- Reference
- 45 Bayesian methods
- The frequentist approach
- The Bayesian approach
- Diagnostic tests in a Bayesian framework
- Disadvantages of Bayesian methods
- Reference
- 46 Developing prognostic scores
- Why do we do it?
- Assessing the performance of a prognostic score
- Developing prognostic indices and risk scores for other types of data
- Reporting guidelines
- Appendices
- Appendix A: Statistical tables
- Reference
- Appendix B: Altman’s nomogram for sample size calculations (Chapter 36)
- Appendix C: Typical computer output
- Appendix D: Checklists and trial profile from the EQUATOR network and critical appraisal templates
- Equator Network Statements
- Critical Appraisal Templates
- Reference
- Appendix E: Glossary of terms
- Appendix F: Chapter numbers with relevant multiple-choice questions and structured questions from Medical Statistics at a Glance Workbook
- Index
- End User License Agreement