Tuberculosis

1. Odd Ratios of getting TB without BCG vaccine among the 13 studies

Explaination: This odd ratios bar chart show that out of 13 studies, the odds of getting TB without BCG vaccine is generally higher than those who have received BCG vaccines in 11 studies. However, there are 2 outliers in the data where the odd ratios are smaller than 1.

2. Relationships between the odds ratio in each study and latitude

Analysis 1 - Relationship between odds ratio and latitude: Based on the first line graph, it appears that there isn’t a very strong correlation between latitude and odds ratio. However, if we exclude the outlier, the second dot on the line graph, we can see the general trend that the higher latitude is, the higher the odds ratios are. Based on this article: seasonality of tuberculosis diagnoses was more pronounced in areas where UV exposure is reduced and vitamin D deficiency is more prevalent. My prediction is that this trend is potentially due to that fact that the higher the latitude is, the more UV exposure is reduced.

3. Relationships between the odds ratio in each study and year

Analysis 2 - Relationship between odds ratio and year: Based on the second line graph, it appears that there isn’t a very strong correlation between year and odds ratio. However, if we exclude the outliers, we can see the general trend that the later the year is, the lower the odds ratios are. This could be caused by the fact that as the health care system is more refined and the BCG vaccines effects are more stabled after multipe testings, the amount of people who are diagnosed with Tuberculosis started to decrease and the effectivness of the BCG vaccines starts to increase.

4. Assessment of the effectiveness of the BCG vaccine

Based on the analyses above, I concluded that the effectiveness of the BCG vaccine is medium high. The first bar graph demonstrated that out of the 13 studies, 11 studies have high odd ratios(higher than 1) of getting TB without BCG vaccine. The effects of BCG vaccine could potentially be unstable because the odd ratios fluctuate based on the latitude and the year.

5. Relationship between relative risks and odd ratios

Analysis 3 - Relationship between odds ratio and relative risks: Based on the scatterplot above, we can conclude that the relative risks are inversely correlated with odd ratios. The higher the relative risks are, the lower the odd ratios are. This correlation makes sense a lower odd ratio means that the effectiveness of the vaccine is low. Thus, the relative risks of getting TB with the vaccine is higher comparing to a more effective vaccine.

Low Birth Weight

Relative risk
Smoking 1.61
Hypertension 1.99
Attending 0 prenatal care visits 1.39
Giving birth before age 20 0.92

Analysis - Based on the calculation, we can conclude that the among the four factors, hypertension status, smoking, and # of times attending prenatal care visits play huge impact on the birth weight. Among all the factors, Hypertension status plays the biggest impact on the risks of having an underweight newborn. Moms who have hypertension is 1.99 times more likely to have an underweight newborn. We can see the relative risks of giving birth to an underweight newborn is 1.61 times higher than those who don’t smoke. Those who attended 0 prenatal care visits is 1.39 times more likely to give birth to an underweight newborn than those who regularly attends prenatal visits. Surprisingly, age doesn’t seem to have a huge impact on birth weight because of the relative risk of giving birth before age 20 is 0.92.

Odds ratios of having Endometrial Cancer

Odd ratios
Presence of Gall bladder disease 3.51
Hypertension status 1.46
Obesity 1.67

Analysis - Based on the calculation, we can conclude that the odd ratio of having Endometrial cancer when gall bladder disease is present is 3.51, which is the highest among the three factors given. The odd ratio of having Endometrial cancer when hypertension is present is 1.46, which is the lowest among the three factors given. Lastly, the odd ratio of having Endometrial cancer with obesity is 1.67. These data shows that endometrial cancer might be closely related to gall bladder functions and that having healthy diet and excersie regularly might reduce the chances of getting Endometrial cancer.