The following ORs are reported for several hypothetical examples. Give you interpretation of the results, assuming all results are statistically significant unless otherwise specified.

a. OR (low-fat diet and colon cancer) = 0.6

b. OR (aerobic exercise and dental caries) = 1.0 (not significant)

c. OR (exposure to side-stream cigarette smoke and lung cancer) = 1.3

d. OR (infectious disease of the pelvis and ectopic pregnancy) = 3.0

Is one of these ORs larger in terms of the magnitude of the relationship between the exposure and outcome? Explain.

OR = 2.0
OR = 0.5

Solution:

Interpretation of “Odds Ratio” (OR) :

OR = 1.0; OR = 0.5; OR = 2.0

Odds ratio can effectively measure the “association between frequency of exposure and health outcome” in statistically significant sample.

Hence when OR = 1.0, it denotes that “absence of any association” among the exposure and disease incidence/health outcome.

When OR = 0.5, it signifies that the “exposure is actually having a protective effect” on health outcome/disease incidence.

When OR = 2.0, Value above 1.0 indicates “positive association existing between disease incidence/health outcome and the exposure”. The OR value 2.0 denotes the disease incidence/health outcome will be twice higher in exposed individuals.

A.

OR=+0.6 for relationship between low fat diet-colon cancer

OR = 0.6, For values less than 1 and above 0.5 it signifies that the “exposure is actually having a protective effect” on health outcome/disease incidence.

B.

OR = +1 for relationship between aerobic exercise -dental caries

when OR = 1.0, it denotes that “absence of any association” between the exposure and disease incidence/health outcome

C.

OR = +1.3 for relationship between exposure to passive cigarette smoking -lung cancer

OR = 1.3, Value above 1.0 indicates “positive association existing between disease incidence/health outcome and the exposure

D.

OR = +3.0 for relationship between pelvis infectious disease- ectopic pregnancy

OR = 3.0, Value above 1.0 indicates “positive association existing between disease incidence/health outcome and the exposure”.