Observational studies are research studies in which researchers collect information from participants or look at data that was already collected. In an observational study, the independent variable is not under the control of the researcher because of ethical concerns or logistical constraints. Observational studies are generally used in hard science, medical, and social science fields. They are used to answer research questions based purely on what the researcher observes, without interference or manipulation of the research subjects.
Observational studies are different from experimental studies, such as randomized controlled trials, where each subject is randomly assigned to a treated group or a control group. In an observational study, the investigator would typically start with a treatment group consisting of those communities where a smoking ban is already in effect. Another difficulty with observational studies is that researchers may themselves be biased in their observational skills.
Well-designed observational studies have been shown to provide results similar to randomized controlled trials, challenging the belief that observational studies are second-rate. Cohort studies and case-control studies are two primary types of observational studies that aid in evaluating associations between diseases and exposures.
Observational studies are usually quite straightforward to design and conduct. As you design your study, you can follow these steps:
- Identify your research topic and objectives.
- Determine what you’re interested in observing and why.
- Choose the type of observational study that best fits your research question.
- Determine the sample size and sampling method.
- Collect data.
- Analyze the data.
- Draw conclusions and report your findings.
In summary, an observational study is a type of research study where researchers collect information from participants or look at data that was already collected, without interference or manipulation of the research subjects. They are used to answer research questions based purely on what the researcher observes, and are generally used in hard science, medical, and social science fields.
