1st Edition
Basic Statistical Techniques for Medical and Other Professionals A Course in Statistics to Assist in Interpreting Numerical Data
We are bombarded with statistical data each and every day, and healthcare professionals are no exception. All sectors of healthcare rely on data provided by insurance companies, consultants, research firms, and government to help them make a host of decisions regarding the delivery of medical services. But while these health professionals rely on data, do they really make the best use of the information? Not if they fail to understand whether the assumptions behind the formulas generating the numbers make sense. Not if they don’t understand that the world of healthcare is flooded with inaccurate, misleading, and even dangerous statistics. The purpose of this book is to provide members of medical and other professions, including scientists and engineers, with a basic understanding of statistics and probability together with an explanation and worked examples of the techniques. It does not seek to confuse the reader with in-depth mathematics but provides basic methods for interpreting data and making inferences. The worked examples are medically based, but the principles apply to the analysis of any numerical data.
CONTENTS
Foreword
Acknowledgement
Introduction
Chapter 1: Why one Needs Statistical Techniques
Variables and Attributes
Spread of a Variable
Correlation
Taking Samples
Chapter 2: Probability and its Rules
Empirical v À Priori
Independence
Mutually Exclusive Events
Exercise 1 – Manipulating Probabilities
Chapter 3: Dealing with Variables
The Mean
Standard Deviation and Variance
Grouped Data
Ranges
Exercise 2 – Mean and Standard Deviation
Inference and Confidence
Coefficient of Variation
Exercise 3 – Mean and Coefficient of Variation
Medians and Percentiles
Exercise 4 – Median Life Expectancy
Geometric Mean
Chapter 4: Comparing Variables
Comparing the Standard Deviations
Comparing the Means
Exercise 5 – Comparing Two Standard Deviations
Chapter 5: Establishing Trends
Visual Presentation of data
Histograms
Graphs
Some Pitfalls
Extrapolation
Logarithmic Scales
Moving Averages
Control Charts
Chapter 6: Dealing with Attributes
Binomial
Poisson Approximation
Exercise 6 – Attributes using Poisson Curves
Chapter 7: Testing for Significance (Attributes)
Chi Squared
Exercise 7 – Chi Squared
Chapter 8: Correlation and Regression
Relating two Variables
Exercise 8 – Correlation
False Correlation
Establishing a Normal Distribution
Chapter 9: Handling Numbers (Large and Small)
Big Numbers
Small Numbers
Multiplying and Dividing
Negative Exponents
Exercise 9 – Large and Small Numbers
Chapter 10: An Introduction to Risk
Individual Risk
Fatal Accident Frequency (FAFR)
Maximum Tolerable Risk
As Low as Reasonably Practicable (ALARP)
Exercise 10 – SLY/Cost per life Saved
Chapter 11: A Final Word
Appendix 1 Manipulating numbers in Spreadsheets
Appendix 2 Brief Glossary of Terms
Appendix 3 Normal Distribution Table
Appendix 4 The F Distribution Tables
Appendix 5 The t Distribution Table
Appendix 6 Cumulative Poisson Curves
Appendix 7 Percentage Points of the Chi Squared Distribution
Appendix 8 Answers to the Exercises
Appendix 9 Further Reading
Biography
Dr. David J. Smith is the Proprietor of Technis Consultancy and has over forty years of experience in reliability and risk assessment and training courses. He is a self-starter who as a leading consultant, and previously as a senior manager in a number of large organizations, has been proactive in the areas of reliability and risk engineering and software quality in both onshore and offshore projects. He’s also a major contributor to national and international standards on functional safety-integrity. An innovator with both management and technical skills in a range of industries who is well known for his contribution to the risk, reliability and quality profession. Author of 8 successful books and numerous papers. Two of his books are regarded as the standard works on the subject. A consultant in his field, for over 30 years, and creator of 6 reliability data and prediction software packages widely used in the profession. His main books are: Reliability, Maintainability and Risk, 9th Edition, Elsevier and The Safety Critical Systems Handbook, 4th edition, 2010, Elsevier.
