RESEARCH METHODOLOGY

Detailed explanation-1: -A longitudinal study is also an observational study, in which data is gathered from the same sample repeatedly over an extended period of time. The longitudinal study can last from a few years to even decades depending on what kind of information needs to be obtained.

Detailed explanation-2: -Observational studies fall under the category of analytic study designs and are further sub-classified as observational or experimental study designs (Figure 1). The goal of analytic studies is to identify and evaluate causes or risk factors of diseases or health-related events.

Detailed explanation-3: -Usually, researchers conduct observational studies when it is difficult, impossible, or unethical to assign study participants to the experimental groups randomly. If you can’t randomly assign subjects to the treatment and control groups, then you observe the subjects in their self-selected states.