Trevathan et al. conducted a case-control study of cigarette smoking and biopsy
ID: 3224255 • Letter: T
Question
Trevathan et al. conducted a case-control study of cigarette smoking and biopsy confirmed carcinoma in situ of the uterine cervix among black women ages 17 to 55 in Atlanta, Georgia in 1980. Cases were women who attended the Dysplasia Clinic and controls were women who attended the Family Planning Clinic. The following table was adapted from a published report. Be sure to interpret all results.
Calculate and interpret the appropriate measure of association of carcinoma in situ associated with low SES, and calculate the same measure of association with medium SES (use high SES as the referent). Which socioeconomic group (low or medium) appears to be more associated with carcinoma in situ?
Calculate the odds of having 10+ sexual partners (using 1-4 as the referent) among cases.
Calculate the odds of having 10+ sexual partners (using 1-4 as the referent) among controls.
Calculate and interpret the odds ratio comparing part b to part c (exposure odds ratio)?
Cases
Controls
Socioeconomic Status
Low
85
165
Medium
39
10
High
26
46
Age at First Intercourse
14 or younger
18
49
15-16
27
130
17-19
30
105
20 and older
4
14
Number of Sexual Partners
1-4
90
190
5-9
37
81
10+
30
55
Cases
Controls
Socioeconomic Status
Low
85
165
Medium
39
10
High
26
46
Age at First Intercourse
14 or younger
18
49
15-16
27
130
17-19
30
105
20 and older
4
14
Number of Sexual Partners
1-4
90
190
5-9
37
81
10+
30
55
Explanation / Answer
Odds of carcinoma in situ associated with low SES=85/165=0.52
Odds of carcinoma in situ associated with medium SES=39/10=3.9
Odds ratio of carcinoma in situ of medium versus low=(39/10)/(85/165)=7.57
So, odds of carcinoma in situ in medium SES group is 7.57 as compared to low SES group.
The odds of having 10+ sexual partners (using 1-4 as the referent) among cases=30/90=0.33
The odds of having 10+ sexual partners (using 1-4 as the referent) among controls=55/190=0.29
The odds ratio comparing part b to part c (exposure odds ratio)=( 30/90)/(55/190)=1.15
The odds of 10+ sexual partners amongst cases is 1.15 times than in controls
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.