Introduction to StatsDirect & SPSS Fourth Year Projects, University of Manchester

1. Introduction to StatsDirect & SPSSFourth Year Projects, University of Manchester Annie Herbert Medical Statistician Research & Development Support Unit Salford Royal Hospitals NHS Foundation Trust annie.herbert@manchester.ac.uk May 2010 (v. 1)

2. Outline • Available packages • Layout • Entering data • Data analysis • Practical tasks

3. Statistics Packages

4. LAYOUT

5. StatsDirect: Data can be entered and stored in a ‘Workbook’.

6. StatsDirect: Plots, tables and analyses can be shown in a ‘Report’.

7. StatsDirect: You can work between many workbooks and reports at a time:

8. SPSS: Data can be entered and stored in ‘Data Editor’.

9. SPSS: Variable names and properties, e.g., data type can be altered in ‘Variable View’.

10. SPSS: This is what the output looks like...

11. ENTERING DATA

12. Spreadsheets

13. Entering Data • Can open Excel files in StatsDirect/SPSS but won’t retain formulae. • If starting from scratch, double click on grey headings to change titles. • If opening Excel file in StatsDirect, titles take up the first row. In SPSS, they become the grey headers. • Make sure one variable per column. • Convert dates/times. • Both packages only deal in numbers, text just for reference so could need coding.

14. Missing Data • StatsDirect treats a blank cell as missing data, but also recognises a ‘*’. • Better to use a ‘*’. • SPSS recognises a ‘.’. • Better to use codes, which can be established in ‘Variable View’. • E.g., for the variable systolic BP, ‘888’ when missing due to refusal to disclose, ‘999’ when missing due to death, etc.

15. CARRYING OUT ANALYSES - STATSDIRECT

16. Analyses are carried out using the menu headings:

17. Anything above this line doesn’t require a worksheet…

18. …for example: 2) 1) 3)

19. Anything below this line requires having a dataset and selecting columns from the worksheet.

20. When performing analyses using the worksheet prompts will appear at each stage specific to type of analysis:

21. You’ll be asked to select the relevant data columns:

22. ‘Groups by column’:

23. ‘Groups by identifier’:

24. Then will give options specific to type of analysis:

25. Select where to display results:

26. Output:

27. CARRYING OUT ANALYSES - SPSS

28. Click on the menu headings:

29. Drag relevant variables into ‘Variable(s)’ box:

30. Different options available for changing display or creating extra graphs:

31. Click ‘OK’, all options selected will come out in a new window:

32. Finally: • StatsDirect: • Readily available on all library PCs and laptops at Salford Royal. • Trial version can be downloaded from www.statsdirect.com • Licence can be requested from the IT Service Desk: www.manchester.ac.uk/servicedesk. • SPSS: • Available on some (university) computers in the library at Salford Royal. • Can be downloaded onto personal computers via http://www.applications.itservices.manchester.ac.uk/show_content.php?id=5. • Extra StatsDirect/SPSS guides and example datasets available on http://www.medicine.manchester.ac.uk/intranet/statistics/statsnotes/.