Douglas G. Altman. Head of Medical Statistical Laboratory ... Statistics in medical research. Statistics at large .... Use and misuse of correlation. Rank correlation.
PRACTICAL STATISTICS FOR MEDICAL RESEARCH Douglas G. Altman Head ofMedical Statistical Laboratory Imperial Cancer Research Fund London
CHAPMAN & HALL/CRC Boca Raton London New York Washington, D.C.
Statistics at large Statistics in medicine Statistics in medical research What does statistics cover? The scope of this book Types of data
Introduction Categorical data Numerical data Other types of data Censored data Variability Importance of the type of data Dealing with numbers
3 3.1 3.2 3.3 3.4 3.5 3.6 3.7
Describing data
4 4.1 4.2 4.3 4.4 4.5
Theoretical distributions
Introduction Averages Describing variability Quantifying variability Two variables The effect of transforming the data Data presentation Exercises Introduction Probability Samples and populations Probability distributions The Normal distribution
The Lognormal distributions The Binomial distribution The Poisson distribution Mathematical calculations The Uniform distribution Concluding remarks Exercises
Introduction Categories of research design Sources of variation An experiment: is the blood pressure the same in both arms? The design of experiments The structure of an experiment Random allocation Minimization Observational studies The case-control study The cohort study The cross-sectional study Studies of change over time Choosing a study design Exercises
6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11
Using a computer
7 7.1 7.2 7.3 7-4 7.5
Preparing to analyse data
Introduction Advantages of using a computer Disadvantages of using a computer Types of statistical program Evaluating a statistical package Strategy for computer-aided analysis Forms for data collection Plotting Other uses of computers Misuses of the computer Concluding remarks Introduction Data checking Outliers Missing data Data screening
Introduction Sampling distributions A demonstration of the distribution of sample means Estimation Hypothesis testing Non-parametric methods Statistical modelling Estimation or hypothesis testing? Strategy for analysing data Presentation of results Summary Exercises Comparing groups - continuous data
Introduction Choosing an appropriate method of analysis The t distribution One group of observations Two groups of paired observations Two independent groups of observations Analysis of skewed data Three or more independent groups of observations One way analysis of variance - mathematics and worked example Presentation of results Summary Exercises Comparing groups - categorical data
Introduction One proportion Proportions in two independent groups Two paired proportions Comparing several proportions The analysis of frequency tables 2 x 2 frequency tables - comparison of two proportions 2 x k tables - comparison of several proportions Large tables with ordered categories
Association, prediction and agreement Correlation Use and misuse of correlation Rank correlation Adjusting a correlation for another variable Use of the correlation coefficient in assessing non-Normality Correlation - mathematics and worked examples Interpretation of correlation Presentation of correlation Regression Use of regression Extensions Regression - mathematics and worked example Interpretation of regression Relation to other analyses Presentation of regression Regression or correlation? Exercises
12 12.1 12.2 12.3 12.4 12.5 12.6 12.7
Relation between several variables
13 13.1 13.2 13.3 13.4 13.5 13.6 13.7
Analysis of survival times
Introduction Analysis of variance and multiple regression Two way analysis of variance Multiple regression Logistic regression Discriminant analysis Other methods Exercises Introduction Survival probabilities Comparing survival curves in two groups Mathematical calculations and worked examples Incorrect analyses Modelling survival - the Cox regression model Desien of survival studies
Some common problems in medical research Introduction Method comparison studies Inter-rater agreement Diagnostic tests Reference intervals Serial measurements Cyclic variation Exercises
396 396 396 403 409 419 426 433 435
15 15.1 15.2 15.3 15.4 15.5 15.6
Clinical trials Introduction Design of clinical trials Sample size Analysis Interpretation of results Writing up and assessing clinical trials Exercises
440 440 441 455 461 471 473 474
16 16.1 16.2 16.3 16.4 16.5
The medical literature Introduction The growth of statistics in medical research Statistics in published papers Reading a scientific paper Writing a scientific paper Exercises
477 477 478 481 493 498 499
Appendix A Mathematical notation
505
Al.l A1.2 A1.3 A1.4 A1.5
505 505 509 510 510
Introduction Basic ideas Mathematical symbols Functions Glossary of notation
