Interpreting Statistical Findings: A Guide for Health Professionals and Students

Jan Walker worked as a health visitor for eight years before taking a degree in psychology and then a PhD which focused pain in later life. Working as a university lecturer and reader, she taught psychology on a wide range of courses for nurses, allied health, medical and social care professionals, from introductory to masters level. She has held honorary contracts with several pain clinics, helping individuals to identify goals and resources for self management. She has conducted, supervised and published research on the lived experience of chronic pain and other chronic conditions. Jan is currently a Visiting Senior Research Fellow at the University of Southampton where she works closely with the Complementary Medicine Research Unit.

• Part 1 Worked ExamplesThe randomised controlled trialThe Health surveyPart 2 Interpreting statistical conceptsMeasuring variables: continuous, ordinal and categorical dataDescribing continuous data: The normal distributionDescribing nonparametric dataMeasuring concepts: Validity and reliabilitySampling data: Probability and non-probability samplesSample size: criteria for judging adequacyTesting hypotheses: what does p actually mean?Part 3 Statistical testsIntroduction to inferential statisticsComparing two independent (unrelated) groups: independent (unrelated) t test, Mann-Whitney U test, contingency analysis- Fisher's exact test and Chi-square testComparing three or more independent (unrelated) groups: One-way ANOVA, Kruskal Wallis test and Chi-square testComparing two sets of related data: Matched pairs or single-sample repeated measures- related (paired) t test, Wilcoxon signed rank test, sign test and McNemar's testComplex group comparisons: ANOVA / ANCOVA, Friedman two-way ANOVA by ranks and Cochrane Q testSimple tests of association: Correlation and linear regressioncomplex associations: Multiple and logistic regressionPart 4 Quick reference guideI Framework for statistical reviewII Glossary of termsIII Guide to statistical symbolsIV Overview of common statistical testsV Guide to the assumptions that underpin statistical testsVI Summary of statistical test selection and resultsVII Extracts from statistical tables