Epidemiological Measures: MMR Vaccination and Autism

Calculating Measure of Association

Case One

When the data provided in the first case is sorted, the organization of both the vaccinated and autistic conditions is shown in this table.

With Autism Without Autism Total
Vaccinated 263 440,392 440,655
Non-Vaccinated 53 96,595 96,648
Total 316 536,987 537,303

Using this table, a 2×2 table can be retrieved and used to calculate the measure of association as shown in the following table.

263 440,392
53 96,595

Calculating the risks of having autism, we have;

Vaccinated: 263/440655=0.0005968

Non-Vaccinated: 53/96648=0.0005483

Risk Ration=0.0005968/0.00005483=1.088

The calculations show that the risk ratio is 1.088 which is very close to 1. As a result, there is no disparity of autistic risk between those who had been vaccinated and the non-vaccinated.

Case Two

PDP Controls Total
Vaccinated with MRM 1010 3671 4681
Non-Vaccinated with MRM 284 798 1082
Total 1294 4469 5673

The 2×2 table matrix for this case would have the following figures.

1010 3671
284 798

The calculation of the cumulative measures for both the vaccinated and the non-vaccinated is as follows;

Vaccinated: 1010/4681=0.2158

Non-Vaccinated: 284/1082=0.2624

Risk Ratio=0.2158/0.2624=0.82

This implies that the people who are vaccinated have 0.82 times the risk of getting the Pervasive Development Disorder as compared to those who are not vaccinated. In essence, vaccination reduces the likelihood of contracting the disorder.

Interpreting Results

Characteristics and Types of Data

Characteristic Type of Data
Sex Qualitative
Birth Weight Quantitative-Continuous
Gestational Age Quantitative-Continuous
Socio-Economic Status Qualitative
Mother’s Education Qualitative
Age at Diagnosis of Autistic Disorder Quantitative-Continuous
Age at Diagnosis of another Autistic-Spectrum Disorder Quantitative-Continuous

Characteristics Showing Differences and No Difference

Characteristics that Showed Difference Characteristics that Showed No Difference
  1. Sex
  2. Age at Diagnosis of Autistic Disorder
  3. Age at Diagnosis of another Autistic-Spectrum Disorder
  1. Birth Weight
  2. Gestational Age
  3. Socio-Economic Status
  4. Mother’s Education

What do these differences mean?

There are some of the characteristics that showed some differences while others did not have any disparity according to the data provided in the figure. Indeed, these differences have crucial meaning to the relationship between the vaccination and lack of vaccination. In particular, the attributes which show some differences influence the effect of vaccination. For example, the age at diagnosis and sex affect the effect of vaccination.

Does data in Figure 2 Show the Association between MMR Vaccine and Risk of Autism?

The data in the second figure does not show an association between MMR vaccination and the risk of autism. This is based on the data provided for the total vaccination and the recorded number of autistic disorders. In this regard, the relative risk is 0.92 which is almost equal to one. As such, there is a very weak and negligible association.

Does data in Figure 3 Show the Association between MMR Vaccine and Risk of Autism?

Since all the p-values are larger than 0.05, it is evident that the null hypothesis cannot be rejected. The null hypothesis is that there is no association between the vaccination and the MMR vaccination.

Conclusion Questions

Although many studies have not identified an association between MMR vaccination and autism, many parents continue to fear the vaccine. This is caused by two reasons. First, although there is no association between the two, some of the people who receive the vaccine contract the disorder (Mitchel, Turner, Jennings, & Dong, 2013). The parents fear that their children could be one of those although there is no association in general. Second, this information might not be known by most of the parents. As a result, they still maintain the traditional misconceptions regarding the association between vaccination and autism. Due to this unawareness, my future role will involve informing parents about the lack of association between the two aspects. The awareness will help to eliminate the prevailing fear among parents with young children.

Reference

Mitchel, P., Turner, N., Jennings, L., & Dong, H. (2013). Previous Vaccination Modifies Both the Clinical Disease and Immunological Features in Children with Measles. Journal of Primary Health Care, 5(2), 93-98.