LECTURE 7 (Presentation an Data Description)
Transcript of LECTURE 7 (Presentation an Data Description)
Learning objective Learning objective
• Be able to prepare software for data presentation and description
Objective and consideration of data Objective and consideration of data presentationpresentation
• ObjectiveTo communicate the information with the viewer
• Requirement Clear Simple Self Explanation
Presenting Categorical DataPresenting Categorical Data
TABLE• SINGLE TABLE• CROSS-TABLE
GRAPH• BAR• PIE
STATISTICS• PERCENT• RATIO
Anemia Data(1= anemia; 2=non anemia)
1 1 2 1 2 1 2 1 2 2 1 2 2 2 1 1 2 2 2 1 1 2 2 2 1 2 2 1 2 2 2 2 1 2 2 1 2 2 1 2 1 1 2 2 21 1 2 2 2 2 2 1 1 2 2 2 1 2 1 1 1 2 1 2 1 2 1 2 2 1 2 2 2 1 1 2 2 2 1 1 2 2 2 1 2 2 1 2 2 2 2 1 2 2 1 2 2 1 2 1 1 2 2 21 1 2 2 2 2 2 1 1 2 2 2 1 2 1 1 1 2 1 2 1 2 1 2 2 1 2 2 2 1 1 2 2 2 1 1 2 2 2 1 2 2 1 2 2 2 2 1 2 2 1 2 2 1 2 1 1 2 2 21 1 2 2 2 2 2 1 1 2 2 2 1 2 1
HOW MUCH IS THE PREVALENCE ?
One Categorical Variable (uni-variate)One Categorical Variable (uni-variate)
What is the prevalence of anemia among pregnant women?Variable : AnemiaTable : Single frequency distribution Statistic : PercentGraph : Bar or Pie
Categories Frequency Percent
Anemia 59 25,5
Non Anemia 172 74,5
Total 231 100,0
The prevalence of anemia among pregnant women is about 25,5%
Table 1. Frequency distribution of anemia among pregnant women in Bali 2008
Source: Bali Health Division
One Categorical Variable…cont)One Categorical Variable…cont)
Graph 1. Pie chart of anemic status of pregnant womens in Bali 2008
Graph 1. Bar chart of anemic status of pregnant womens in Bali 2008
0
20
40
60
80
Pregnant women
AnemiaNon Anemia
Source: Bali Health Division Source: Bali Health Division
DATA ANEMIA (1= anemia; 2=non anemia)
GIANYAR:1 1 2 1 2 1 2 1 2 2 1 2 2 2 1 1 2 2 2 1 1 2 2 2 1 2 2 1 2 2 2 2 1 2 2 1 2 2 1 2 1 1 2 2 21 1 2 2 2 2 2 1 1 2 2 2 1 2 1 1 1 2 1 2 1 2 1 2 2 1 2 2 2 1 KARANGASEM: 1 2 2 2 1 1 2 2 2 1 2 2 1 2 2 2 2 1 2 2 1 2 2 1 2 1 1 2 2 21 1 2 2 2 2 2 1 1 2 2 2 1 2 1 1 1 2 1 2 1 2 1 2 2 1 2 2 2 1 1 2 2 2 1 1 2 2 2 1 2 2 1 2 2 2 2 1 2 2 1 2 2 1 2 1 1 2 2 2
HOW MUCH IS THE PREVALENCE ?
Two Categorical Variables (bi-variate)Two Categorical Variables (bi-variate)What is the prevalence of anemia among pregnant women in each district?Variable : Anemia and DistrictTable : Cross-Tabulation Statistics : Percent (specific prevalence), RatioGraph : Bar (clustered or stacked bar)
Anemia Non Anemia TotalGianyar : count row%
3324,4%
10275,6%
135100%
Krgasem : count row%
2627,1%
7072,9%
96100%
Total : count row%
5925,5%
17274,5%
231100%
Table 2. Cross tabulation of districts and anemic status of pregnant women in 2008
Bar ChartBar ChartClustered Bar Stacked Bar
DATA CHD (1= CHD; 2=non CHD)
SMOKING:1 1 2 1 2 1 2 1 2 2 1 2 2 2 1 1 2 2 2 1 1 2 2 2 1 2 2 1 2 2 2 2 1 2 2 1 2 2 1 2 1 1 2 2 21 1 2 2 2 2 2 1 1 2 2 2 1 2 1 1 1 2 1 2 1 2 1 2 2 1 2 2 2 1 NON SMOKING: 1 2 2 2 1 1 2 2 2 1 2 2 1 2 2 2 2 1 2 2 1 2 2 1 2 1 1 2 2 21 1 2 2 2 2 2 1 1 2 2 2 1 2 1 1 1 2 1 2 1 2 1 2 2 1 2 2 2 1 1 2 2 2 1 1 2 2 2 1 2 2 1 2 2
DOES SMOKING RELATED TO CHD ?
Two Categorical Variables (bi-variate)Two Categorical Variables (bi-variate)
Does smoking increase the risk for CHD?Variable : smoking (independent) and CHD (dependent)Table : Cross-Tabulation Statistic : Percent, Ratio (RR or OR)
Smoking CHD Non CHD TotalYes : count colm%
8585%
2525%
11055%
No : count colm%
1515%
7575%
9045%
Total : count colm%
100100%
100100%
200100%
Table 3. Cross-tabulation of smoking and CHD
Odd RatioOdd Ratio
Disease + Disease - Total
Expose+ A B A+B
Expose - C D C+D
Total A+C B+D n
Table 2 x 2
BCAD
DBCA
OddOdd
OddRatio
DB
DBDDBB
DEPDEPOdd
CA
CACCAA
DEPDEPOdd
disease
disease
disease
disease
//
)/()/(
)|()|(
)/()/(
)|()|(
)(
)(
)(
)(
Odd Ratio
Odd Ratio for Case-ControlOR = 1, equal oddOR > 1, increasing the oddOR < 1, decreasing the odd
INTERPRETATION
OR = (85 x 75)/(25 x 15) = 17
Smoking CHD Non CHD TotalYes : count colm%
8585%
2525%
11055%
No : count colm%
1515%
7575%
9045%
Total : count colm%
100100%
100100%
200100%
The odds of CHD among smoker 17 times higher then non smoker
RELATONSHIP SMOKING AND CHD
Table 3. Cross-tabulation of smoking and CHD
Prevalence Ratio andPrevalence Ratio andRelative RiskRelative Risk
Disease + Disease - Total
Expose+ A B A+B
Expose - C D C+D
Total A+C B+D n
Table 2 x 2
)/()/(..
)(
)(
)(exp
)(exp
DCCBAAPRatauRR
DCCIncidence
BAAIncidence
ose
ose
PR or RR
PR: for Cross-Sectional DesignRR: for Cohort Design
INTERPRETATIONRR = 1, equal riskRR > 1, increasing the riskRR < 1, decreasing the risk
RR = 0,77 / 0,17 = 4,5
INTERPRETATION The risk of CHD among smoker 4,5 times higher then non smoker
RELATONSHIP SMOKING AND CHD
Smoking CHD Non CHD TotalYes : count row%
8577%
2523%
110100%
No : count row%
1517%
7583%
90100%
Total : count row%
10050%
10050%
200100%
Table 4. Cross-tabulation of smoking and CHD
Presenting Continuous DataPresenting Continuous Data
TABLE• SINGLE TABLE
GRAPH• HISTOGRAM• LINE• SCATTER DIAGRAM
• FREQUENCY• TENDENCY CENTRAL: Mean, Median Modus• VARIABILITY: Range, SD, Variation Coefficient
STATISTICS
PARITY DATA
1 0 2 1 0 1 2 1 2 2 1 2 2 2 1 0 2 2 2 1 0 0 2 0 1 2 2 1 2 0 2 4 1 3 2 1 2 0 1 0 0 1 2 1 21 1 2 2 0 2 0 1 1 2 2 2 1 2 1 3 1 2 1 2 1 2 1 0 3 1 2 2 0 1 1 2 2 0 1 3 1 2 2 1 2 2 1 2 2 0 0 1 2 2 1 2 3 1 2 0 1 2 3 21 1 2 2 3 2 3 1 1 2 2 2 1 2 1 4 1 2 1 2 1 2 1 0 0 1 2 2 2 1 1 3 2 0 1 0 0 2 2 1 3 2 1 1 2 2 0 1 2 0 1 2 2 1 2 1 1 2 2 40 1 2 3 0 2 5 1 3 1 2 2 1 2 1
HOW DO YOU DESCRIBE THIS DATA ?
One Continues DataOne Continues DataWhat is the parity of sample?Variable : ParityTable : Single frequency distribution Statistic : Mean, Range, SDGraph : Histogram, Line Chart
PARITY FREQUENCY PERCENT0 25 10,81 47 20,32 74 32,03 51 22,14 22 9,5
> 4 12 5,2TOTAL 231 100,0
STATISTICS• MINIMUM : 0• MAXIMUM: 5• MEAN : 3,15• SD : 1,3
Table 5. Frequency Distribution of parity among reproductive women in Bali 2008
TENDENCY CENTRALTENDENCY CENTRALmean, median, modusmean, median, modus
MEAN (AVERAGE) MEDIAN
Data: 0 1 2 3Mean = (X1+X2+X3+X4)/4 = 6/4 = 1,5
Data: 0 1 2 3Median = (x2+x3)/2 = 3/2 = 1,5
Data: 0 1 2 15Mean = (X1+X2+X3+X4)/4 = 18/4 = 4,5
Data: 0 1 2 15Median = (X2+X3)/2 = 3/2 = 1,5
• Distorted by outlier and Skewed data
• Not distorted by outlier and Skewed data
Normal distribution
Mean = Med=Mod
Mod Med Mean
Mean med Mod
Mod < Med < Mean
Mean<Med<Mod
DISVERSIONDISVERSIONVariance and Standard DeviationVariance and Standard Deviation
Data : 0 1 2 3Mean = 6/4 = 1,5
Mean 0 0,5 1 1,5 2 2,5 3
x1 (x1-Mean)
x2 (x2-mean)
x3
x4(x4-mean)
1
2
n
XXSD i
SD= (0-1,5)2+(1-1,5)2+(2-1,5)2+(3-1,5)2/(4-1) = 1,29
DISVERSIONDISVERSIONrange, percentile, quartilerange, percentile, quartile
Data : 0 1 1 1 2 2 2 3 4 7
RANGE = 7 – 0 =7Percentile 10 = 0Percentile 25 = 1Percentile 30 = 1Percentile 50 = 2Percentile 75 = 2,5Percentile 80 = 3
Quartile 1 = 1 (percentile 25)Quartile 2 = 2 (percentile 50)Quartile 3 = 2,5 (percentile 75)Quartile 4 = 7 (percentile 100)
FIRST QUARTILE
THIRD QUARTILE
MEDIAN
LOWER LIMIT
UPPER LIMIT
BOX PLOT
50%
25%
25%
Grouping DataGrouping Data
• Purpose- to meet the objective of study
- to make it simplerExample:
Age (year); grouping into 5 years interval: 0-4, 5-9, 10-14, 15-19, …. 85-.
Umur ibu
1 ,4 ,4 ,43 1,3 1,3 1,75 2,2 2,2 3,96 2,6 2,6 6,56 2,6 2,6 9,14 1,7 1,7 10,8
18 7,8 7,8 18,612 5,2 5,2 23,815 6,5 6,5 30,312 5,2 5,2 35,510 4,3 4,3 39,85 2,2 2,2 42,09 3,9 3,9 45,9
11 4,8 4,8 50,68 3,5 3,5 54,19 3,9 3,9 58,0
14 6,1 6,1 64,19 3,9 3,9 68,0
20 8,7 8,7 76,612 5,2 5,2 81,814 6,1 6,1 87,915 6,5 6,5 94,49 3,9 3,9 98,33 1,3 1,3 99,61 ,4 ,4 100,0
231 100,0 100,0
17181920212223242526272829303132333435363738394041Total
ValidFrequency Percent Valid Percent
CumulativePercent
klp_umur
9 3,9 3,9 3,946 19,9 19,9 23,851 22,1 22,1 45,951 22,1 22,1 68,070 30,3 30,3 98,34 1,7 1,7 100,0
231 100,0 100,0
15-1920-2425-2930-3435-3940-44Total
ValidFrequency Percent Valid Percent
CumulativePercent
Before grouping
After grouping
SPSS: calculate the statistics based on new categories and not based on the age data.
Before grouping After grouping