1. Laying out the data Designing effective tables FETP India

2. Competency to be gained from this lecture Lay out data effectively in tables

3. Key areas Essential rules when arranging a table Common tables in epidemiology

4. Communicating patterns and messages contained in your data Show the patterns inherent in the data Focus attention on these patterns Serve as a basis for narrative or discussion Lead observer to insight, discussion, conclusions

5. Avoid visual puzzles in tables Poorly organized data Series of complicated numbers Important data obscured Unnecessary frames, lines, coloring Decoration Basic table rules

6. Column headings Data Footnotes Title Row headings Typical table layout with components

7. Making sure that a table is understandable without referral to other material Title  Person  Time  Place  Any measurement found in all columns Row and column headings  Content of the row or column  Any modifier applied to all cells of a row or column  Unit of measurement  Abbreviations, if necessary Basic table rules

8. Using footnotes in a table Clarify points of potential ambiguity Explain all:  Abbreviations  Symbols  Codes Note exclusions Mention data source if applicable Basic table rules

9. *ASC Ehrenberg, J R Statis Soc A, 140(3):277-297, 1977 Suggestions for data arrangement in tables * 1.Round data to 2 meaningful figures 2.Summarize rows and columns 3.Compare numbers in columns 4.Arrange key data by magnitude 5.Help the reader with easy table layout 6.Align numbers by decimal Basic table rules

10. Table with excessive number of meaningful figures FactorCasesRate Rate Ratiopapa None274512.3451.000Ref b A342113.4331.4640.1011 B110025.6612.4140.0133 C56436.0012.5590.0005 a. p-value b. Reference exposure category Up to five meaningful figures Rate ratios difficult to compare 1. Round data to 2 meaningful figures Basic table rules

11. Rounding data in a table to 2 meaningful figures Factor Cases (1000s)Rate Rate ratiop None272.32.31.01.0Ref* C343.43.41.51.5>0.100 A115.75.72.42.4<0.050 B06066.06.02.62.6<0.001 a. p-value b. Reference exposure category 2 meaningful figures Rate ratios easier to compare 1. Round data to 2 meaningful figures Basic table rules

12. YearMF Both Sexes 197350099600 197058087670 196846089550 196626071330 Mean43086520 Summary of the columns Summary of the rows 2. Summarize rows and columns Summarizing rows and columns with totals, averages or other statistics Basic table rules

13. Compare numbers in columns 23 42 34 109 87 42 27 98 114 75 Difficult to compare numbers in rows 23 42 34 109 87 42 27 98 114 75 1st improvement: Right-justify numbers vertically 23 27 34 42 75 87 98 109 114 2nd improvement: Sort numbers 3. Compare numbers in columns Basic table rules

14. Organize data by magnitude Exposure Cases (1000s)Rate Rate ratioPaPa A112.91.3> 0.100 B069.94.3< 0.001 C345.42.3> 0.100 None272.31.0Ref b 4. Arrange key data by magnitude a. p-value b. Reference exposure category Basic table rules

15. Organize data by magnitude Exposure Cases (1000s)Rate Rate ratiopapa B69.94.3< 0.010 C345.42.3< 0.050 A112.91.3> 0.001 None272.31.0Ref b a. p-value b. Reference exposure category 4. Arrange key data by magnitude Basic table rules

16. Year Both sexesMaleFemale 197360050099 197067058087 196855046089 196633026071 Spaced out table layout: Comparisons difficult for the reader 5. Help the reader with easy table layout Basic table rules

17. Year Both sexesMaleFemale 197360050099 197067058087 196855046089 196633026071 5. Help the reader with easy table layout Drawing columns and rows close together facilitates comparisons Basic table rules

18. Intervening statistics: Separated numbers are harder to compare Rate per 1000 YearMaleFemaleAll 1993837880 2.32.21.9 1994626663 2.52.71.8 1995585456 2.12.01.7 1996554551 2.0 1.7 5. Help the reader with easy table layout Basic table rules

19. Rate per 1000 (SE) YearMaleFemaleAll 199383 (2.3) 78 (2.2) 80 (1.9) 199462 (2.5) 66 (2.7) 63 (1.8) 199558 (2.1) 54 (2.0) 56 (1.7) 199655 (2.0) 45 (2.0) 51 (1.7) Moving and minimizing intervening numbers facilitates readability 5. Help the reader with easy table layout Basic table rules

20. Rate per 1000 a YearMFAll 1993837880 1994626663 1995585456 1996554551 a. Standard errors for all rates less than 5% of rate. Remove intervening numbers entirely if consequence minimal 5. Help the reader with easy table layout Basic table rules

21. Align columns by decimal 23 42 34 10.9 8.7 42 27 9.8 114 75 23.0 42.0 34.0 10.9 8.7 42.0 27.0 9.8 114.0 75.0 Difficult to compare numbers in rows Keeping the zeros or not is a question of personal style 6. Align numbers by decimal Basic table rules

22. Arranging common types of tables in epidemiology Text table Line listing Two variable table Complex table Cohort study Case-control study Common tables

23. Text table Between July 1 and August 31, 72 cases occurred in three classes of school A. Class Cases 1 23 2 31 3 18 No cases occurred in the six other classes. a. Text table Common tables

24. StateAge 1 SexDays 2 Dose New York02M031 California03M 1 Pennsylvania06M031 Pennsylvania02M041 Colorado04F 1 California07M042 Kansas02F051 Colorado03M051 New York03F051 North Carolina04F051 Missouri11M051 Pennsylvania03F071 California04F142 Pennsylvania02M291 California05M591 1. Age in months * MMWR, 48 (27):577 2. Days from dose to symptom onset Reported cases of intussusception among recipients of rotavirus vaccine, by state, United States, 1998-1999* b. Line listing Common tables

25. New cases of primary and secondary syphilis by age group and sex, United States, 1989 Age groupCases (100’s) (years)MaleFemaleTotal  14 0.41.91.92.32.3 15-1917.427.944.3 20-2451.453.9100.3 25-2953.442.996.3 30-3455.431.986.3 35-4450.419.969.3 45-5421.449.926.3  55 11.413.913.3 Total260.4180.9440.3 c. Two variable table Common tables

26. Complex table Children CharacterExp % (n=205) Not exp% (n=8729)p Gestational age (weeks) at birth <255.8140.04 25-2918.019NS Birthweight (kg) 1.5 --15.015NS 2.5 --39.043NS d. Complex table Common tables

27. Exposed %YesNo ExposureRes. a %AR b RR c (95% CI d ) Type 1 Sub Type 1-A( - ) Sub Type 1-B( - ) Sub Type 1-C( - ) Type 2( - ) Type 3( - ) Type 4: a. Res. = Responded c. RR = Risk Ratio b. AR = Attack Rate – cases per ___ d. 95% CI = 95% confidence interval of the RR e. Cohort study Risk of ______ by exposure, among #### residents of Place, time Common tables

28. Exposed Exposure%AR a RR b 95% CI c Type or Level 3 Type or Level 2 Type or Level 1 None or Level 01.0Referent b. RR = Risk Ratio c. 95% CI = 95% confidence interval of the RR a. AR = Attack Rate – cases per ___ Risk of ______ by exposure, among #### residents of Place, time e. Cohort study (reference group) Common tables

29. Exposed % (n) a ExposureCasesControlsOR b 95% CI c Type 1 (n) ( – ) Sub Type 1-A (n) ( – ) Sub Type 1-B (n) ( – ) Sub Type 1-C (n) ( – ) Type 2 (n) ( – ) Type 3 (n) ( – ) c. 95% CI = 95% confidence interval of the OR a. n = subjects respondingb. OR = Odds Ratio Exposures (%) among ### cases and ### controls, Place, Time f. Case control study Common tables

30. Take home messages Design your table around the message that is contained in your data Refer to templates that apply to the table you are trying to design