Chi Square, OR, RR (associations between categorical variables) Problem 3 The da
ID: 3325668 • Letter: C
Question
Chi Square, OR, RR
(associations between categorical variables)
Problem 3
The data file stenosis_smokers.sav describes a study of 215 smokers and non-smokers. The participants are evaluated for stenosis (narrowing of coronary arteries). Use SPSS to perform the following analyses (paste in the relevant tables:
State your null and alternative hypotheses for a chi square analysis
a. Organize the data into a contingency table (exposure/smoking in the rows, outcome/stenosis in the columns). Calculate the expected values Calculate the percentages by rows
Paste a table with your results below
b. Report the chi square value
c. Report the p value for this chi square
d. Do you reject your null hypothesis?
Calculate the odds ratio and relative risk for smoking and stenosis.
Paste a table with your results below
e. Report the relative risk for smoking and stenosis
f. Report the 95% CI for relative risk
g. State your null hypothesis for relative risk. (hint what would the expected value for the Relative Risk or Odds Ratio equal if there is no association between
h. Do you reject your null hypothesis?
i. Report the odds ratio for smoking and stenosis
j. State your null hypothesis for odds ratio
k. Do you reject your null hypothesis?
This information is taken from a SPSS file Stenosis_smokers.sav
Smoke disease Gender
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 1.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 1.00 .00
1.00 2.00 .00
1.00 1.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 1.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 2.00 .00
1.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 1.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 2.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
2.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
1.00 1.00 .00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
2.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
1.00 2.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
2.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
1.00 1.00 1.00
Variable view
smoke Numeric 9 2 smoking status {1.00, yes}... None 8 Right Nominal Input
disease Numeric 9 2 presence of aortic stenosis {1.00, yes}... None 8 Right Nominal Input
Gender Numeric 9 2 gender {.00, Female}... None 8 Right Nominal Input
Explanation / Answer
Result:
State your null and alternative hypotheses for a chi square analysis
Ho: There is no association between smoking and disease.
H1: There is association between smoking and disease
a. Organize the data into a contingency table (exposure/smoking in the rows, outcome/stenosis in the columns). Calculate the expected values Calculate the percentages by rows
Paste a table with your results below
Smoke * disease Crosstabulation
disease
Total
1.00
2.00
Smoke
1.00
Count
54
40
94
% within Smoke
57.4%
42.6%
100.0%
2.00
Count
44
77
121
% within Smoke
36.4%
63.6%
100.0%
Total
Count
98
117
215
% within Smoke
45.6%
54.4%
100.0%
Chi-Square Tests
Value
df
Asymptotic Significance (2-sided)
Exact Sig. (2-sided)
Exact Sig. (1-sided)
Pearson Chi-Square
9.480a
1
.002
Continuity Correctionb
8.649
1
.003
Likelihood Ratio
9.527
1
.002
Fisher's Exact Test
.002
.002
N of Valid Cases
215
a. 0 cells (0.0%) have expected count less than 5. The minimum expected count is 42.85.
b. Computed only for a 2x2 table
b. Report the chi square value
chi square=9.48
c. Report the p value for this chi square
P=0.002
d. Do you reject your null hypothesis?
Calculated p=0.002 < 0.05 level, Ho is rejected.
Calculate the odds ratio and relative risk for smoking and stenosis.
Paste a table with your results below
Risk Estimate
Value
95% Confidence Interval
Lower
Upper
Odds Ratio for Smoke (1.00 / 2.00 )
2.363
1.361
4.102
For cohort disease = 1.00
1.580
1.179
2.118
For cohort disease = 2.00
.669
.510
.877
N of Valid Cases
215
e. Report the relative risk for smoking and stenosis
relative risk =1.58
f. Report the 95% CI for relative risk
95% CI =(1.179, 2.118)
g. State your null hypothesis for relative risk. (hint what would the expected value for the Relative Risk or Odds Ratio equal if there is no association between
Ho: RR =1
h. Do you reject your null hypothesis?
Yes, we reject Ho, because 95% CI not contains the value 1.
j. State your null hypothesis for odds ratio
Ho: OR =1
k. Do you reject your null hypothesis?
Yes, because 95% CI not contains the value 1.
Smoke * disease Crosstabulation
disease
Total
1.00
2.00
Smoke
1.00
Count
54
40
94
% within Smoke
57.4%
42.6%
100.0%
2.00
Count
44
77
121
% within Smoke
36.4%
63.6%
100.0%
Total
Count
98
117
215
% within Smoke
45.6%
54.4%
100.0%
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.