Question

For this Case Study Assignment, you will analyze and interpret the epidemiological evidence for a possible association between vaccination with the measles/mumps/rubella (MMR) vaccine and the occurrence of autism.

To prepare for this Assignment, access the following document, also located in the Learning Resources:

Simeonsson, K., Bethel, J., & Lea, S. (n.d.). Weighing the evidence: Misconceptions about measles-mumps-rubella (MMR) vaccine and autism. Retrieved from Association for Prevention Teaching and Research website: http://c.ymcdn.com/sites/www.aptrweb.org/resource/resmgr/prevention_modules/module_2_student_case.pdf

Using the information provided in the case study, complete Sections B, C, and D (pp. 5–10), typing your answers into a separate document.

Be sure that your completed document contains your responses to all questions from Sections B, C, and D of the case study.

Answer 1

SECTION B

1. Cohort study by Madsen et al (NEJM 2002)

The table below shows the number of children who had been vaccinated and those who had not. A test of correlation was carried out using EXCEL and the results are as shown in table 2.

Table 1: Number of children who had been vaccinated and those who had not

Vaccinated	Not vaccinated
440655	96648
263	53

Table 2: Correlation between vaccinated and vaccinated children

	Vaccinated	Not vaccinated
Vaccinated	1
Not vaccinated	1	1

From the results, vaccinated and unvaccinated children had a correlation of 1, implying that there was indeed a relationship between the vaccinated and those not vaccinated. Therefore there was no association between MMR vaccination and the risk of autism according to the results.

2. Case control study by Smeeth et al (Lancet 2004)

Table 3: Number of vaccinated and unvaccinated children in the control case

Vaccinated	Not vaccinated
1010	284
3671	798

Table 4: Correlation between the number of vaccinated and unvaccinated children under the control case.

	Vaccinated	Not vaccinated
Vaccinated	1
Not vaccinated	1	1

With the control case, vaccinated and unvaccinated children had a correlation of 1, implying that there was a relationship between the vaccinated and those not vaccinated. This again, shows that there was no association between MMR vaccination and the risk of autism.

SECTION C

Question 1

Continuous data in table one include: birth weight, gestation age, age at diagnosis of autistic disorder and age at diagnosis of another autistic- spectrum disorder.

Discrete data include: sex, socioeconomic status and mother’s education.

All these data is quantitative.

Question 2

Characteristics which showed differences between the two groups had a p- value less than 0.05, while those which showed no differences between the two groups had a p- value greater than 0.05. Therefore, characteristics which showed differences between the two groups include: birth weight, gestational age, socioeconomic status and mother’s education.

Characteristics which showed no differences between the two groups include:   sex, age at diagnosis of autistic disorder, age at diagnosis of autistic- spectrum disorder.

Question 3

The differences between the two groups show that the characteristics under which differences between the two groups were present caused disparities between people with varying characteristics. Example, disparities might be present between two patients with different body weights, where one is vaccinated and the other is not.

Question 4

To answer this question, the confidence interval of vaccination will be considered. Total vaccination, age at vaccination, interval since vaccination and date of vaccination all returned 95% confidence intervals which lied within the given 95% confidence limits. This implies that figure 2 shows an association between MMR vaccine and risk of autism.

Question 5

In figure 3, results in table one show p- values which are greater than 0.05 for all the ages at which vaccination was given. This implies that there is an association between MMR vaccine and risk of autism. Similarly, table two shows p- values greater than 0.05 for autism only and other PDD’s only. This again confirms that there is an association between MMR vaccine and risk of autism.

SECTION D

Most parents are reluctant about taking their children for vaccination due to the fear that the vaccines might cause health problems. In some developing countries, several children have died after being vaccinated using, probably, expired or untested vaccines.

As a future health care provider, I would first ensure vaccines are safe for use on patients. Secondly, I would increase confidence of parents in vaccines by educating them about the importance of proper vaccinations at accredited health facilities. I would educate them about the dreadful risks of avoiding vaccinations. These would help restore confidence of parents in vaccines, therefore increasing the number of vaccinated children and as a result, improve the health standards of growing children.