Study Population vs. Target Population

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Definition

The study population is the specific group of individuals who actually participate in a study. The target population is the broader group to whom the results are intended to apply. The gap between these two populations determines how generalizable results are.

Correct Scientific Usage

Researchers define eligibility criteria to determine who can be included in a study. Those enrolled make up the study population. The target population is often larger and more diverse, such as all patients with a given condition.

The larger the difference between study and target populations, the more cautiously findings should be interpreted. Scientists acknowledge when their study population may not adequately represent their target population.

Common Misunderstandings

People often assume the study population and target population are the same or believe that conclusions apply equally to people excluded from the study.

There's also confusion about why researchers don't simply study everyone. Practical constraints—cost, time, accessibility—mean most studies use narrower populations than their ultimate target.

Why It Matters

Recognizing the difference between study and target populations helps evaluate whether research findings apply to specific situations. This distinction explains why treatments may perform differently in real-world settings than in clinical trials.

References

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