Question

As part of a disability services research project, an MPH student is analyzing data from a special survey conducted in Missouri. This survey was adapted from the Behavioral Risk Factor Surveillance System (BRFSS). The survey was a random digit dial telephone survey conducted in six Missouri counties between 2010 and 2012. The sample consisted of 3,343 adults: 1,380 from rural and 1,963 from nonrural areas. The survey collected information on residential information and the presence of a disability. Disability was defined as “activities are limited in any way because of an impairment or health problem.” The student hypothesized that disability would be increased in rural areas.

1. What kind of study is this and why?
2. What are the main concerns to make the causal inference based on the data from this study?

Answer 1

a) Firstly I am lacking clarity in this question. Still, my answer would be that the study is a sample-based social survey involving quantitative analysis. Because,

• the research is probing into a social or health issue,
• it is a sample study using which we will be making inferences for the whole population.

b) As the question states that "the student hypothesized that disability would be increased in rural areas", the same is the main concern of the study. Whether the proposed hypothesis is right or wrong, i.e., whether the disability is more on rural areas or not. In order to prove this, you can use the sample and draw inferences accordingly. The data here can be two -way classified based on rural or non-rural and disabled or not as shown in the fig given below.

	Disabled	Not Disabled
Rural	-	-
Non-Rural	-	-

You can do a chi-square test for association to find out whether there is an association between the number of disabled with the type of place they are living(rural/urban)

Another analysis that you can do here is the time series analysis and study the trends in the data.