Complete Question:
A study enrolled 517 children aged two to five years with a diagnosis of autism spectrum disorder and 315 control children of the same age group but without such a diagnosis. Information was collected about metabolic conditions of the mothers at the time of their pregnancy, such as type 2 diabetes, hypertension, and obesity. Metabolic conditions during pregnancy tended to be more frequent among the mothers of children with autism spectrum disorder than among mothers of control children. This is __________
Answer:
This is an observational study with a case-control design
Explanation:
An Observational study is a study in which researchers observe the outcomes of an intervention, a test, a treatment or a risk factor on a test population without intervening or influencing what part of the population is exposed.
There are two types of observational studies:
1. Cohort studies
2. Case control studies
The cohort study is a type of observational study that identifies a population exposed to a particular factor and compares them with another group that was not exposed to that factor, measuring and comparing outcomes in the two groups.
The case-control study involves using a different strategy of sampling whereby the population that develops outcomes from exposure to a particular factor is compared with those that did not, after exposure.