Statistical presentation in international scientific publications 5. A statistical review (group work) Malcolm Campbell Lecturer in Statistics, School of Nursing, Midwifery & Social Work, The University of Manchester Statistical Editor, Health & Social Care in the Community

26 March 2008Statistical presentation - 5. A statistical review2 5. A statistical review Contents 5.1 Layout 5.2 Study design 5.3 Statistical methods 5.4 Conduct of the study 5.5 Statistical analysis and presentation 5.6 Overall assessment

26 March 2008Statistical presentation - 5. A statistical review3 The review paper Specially prepared to illustrate statistical review “A comparison study of the effect of a hospital at home service for palliative care on whether or not a patient dies at home” –a “bad exemplar”, based on a real paper published in a leading medical journal –the Abstract, Methods and Results have been re- written “badly” to show common faults with papers submitted to healthcare journals –with kind permission of the authors Reminder: this is just an example of a statistical review – it should not be seen as definitive

26 March 2008Statistical presentation - 5. A statistical review4 It’s group work time! Split up into four groups to discuss one of the following Group 1 Layout and Abstract, with CONSORT checklist items 1, 22, 13, 16 & 17 Group 2 Study design Group 3 Statistical methods and conduct of study Group 4 Statistical analysis and presentation Use the handouts for the group work session –A – paper for statistical review –B – statistical review checklist –Group 1 only – CONSORT checklist

26 March 2008Statistical presentation - 5. A statistical review5 5.1 Layout Checklist and comments Layout (All, Abstract)YesUnclearNoN/A 1Did the paper follow the Introduction-Methods-Results- Discussion format? 2Did the paper conform to CONSORT/TREND/STROBE/ STARD for RCT/non-randomised design/observational study/diagnostic accuracy? 3Was the Abstract correctly structured and sufficiently informative?

26 March 2008Statistical presentation - 5. A statistical review6 5.2 Study design 1 Checklist and comments Study Design (Introduction, Methods)YesUnclearNoN/A 1Were the objectives of the study sufficiently described? 2Was an appropriate study design used to achieve the objectives? 3Was the design of the study sufficiently described? 4Were source and inclusion/exclusion criteria clearly described for participants?

26 March 2008Statistical presentation - 5. A statistical review7 Study design 2 Checklist and comments Study design (Introduction, Methods)YesUnclearNoN/A 5Were methods used for randomisation or sampling clearly described? 6Was the sample of participants appropriate with respect to the population to which the findings will be generalised? 7Were standard, validated instruments (eg questionnaires) used for data collection? If not, were the instruments used validated during the study?

26 March 2008Statistical presentation - 5. A statistical review8 Study design 3 Checklist and comments Study design (Introduction, Methods)YesUnclearNoN/A 8Was the sample size based on pre-study considerations of statistical power? 9Were ethical approval and participants’ consent reportedly obtained?

26 March 2008Statistical presentation - 5. A statistical review9 5.3 Statistical methods Checklist and comments Statistical methods (Methods)YesUnclearNoN/A 1Were the statistical methods used adequately described or referenced? 2Were the statistical methods used appropriate for the data? 3Were the name and version of the software used for data analysis given?

26 March 2008Statistical presentation - 5. A statistical review Conduct of the study Checklist and comments Conduct of the Study (eg Methods, Results)YesUnclearNoN/A 1Were dates, clinical settings and geographical locations given for data collection? 2Were satisfactory sample size/participation rate achieved and clearly reported? 3Were missing data properly accounted for?

26 March 2008Statistical presentation - 5. A statistical review Statistical analysis & presentation 1 Checklist and comments Statistical Analysis and Presentation (eg Results, Discussion, Tables) YesUnclearNoN/A 1Were relevant characteristics of the participants adequately summarised? 2Were percentages and descriptive statistics correctly reported? 3Were the statistical methods applied correctly in data analysis?

26 March 2008Statistical presentation - 5. A statistical review12 Statistical analysis & presentation 2 Checklist and comments Statistical Analysis and Presentation (eg Results, Discussion, Tables) YesUnclearNoN/A 4Were confidence intervals given for the main results? 5Were significance test results and confidence intervals correctly reported?

26 March 2008Statistical presentation - 5. A statistical review13 Statistical analysis & presentation 3 Checklist and comments Statistical Analysis and Presentation (eg Results, Discussion, Tables) YesUnclearNoN/A 6Were all statistical tables and figures necessary and clearly laid out?

26 March 2008Statistical presentation - 5. A statistical review14 Statistical analysis & presentation 4 Checklist and comments Statistical Analysis and Presentation (eg Results, Discussion, Tables) YesUnclearNoN/A 7Were all statistical tables and figures able to stand alone from the text? 8Were sufficient descriptive or inferential analyses presented? 9Were any conclusions drawn from the statistical analyses justified?

26 March 2008Statistical presentation - 5. A statistical review Overall assessment 1 Checklist and comments * Subject to the modifications indicated above Overall assessmentYesMinor revision* Major revision* No In your opinion, is the paper statistically acceptable?

26 March 2008Statistical presentation - 5. A statistical review16 Overall assessment 2 Conclusion Well, what do you think?