Skip to Main Content


At the end of the chapter, the reader will be able to:


  1. Identify the general purposes of research

  2. Discuss the important principles of study design

  3. Distinguish between experimental, quasi-experimental, and observational approaches to pharmacoepidemiologic research

  4. Describe various quasi-experimental study designs used in pharmacoepidemiology

  5. Describe various observational study designs used in pharmacoepidemiology

  6. Discuss the relative advantages and disadvantages of the various study designs

  7. Describe the role of meta-analysis in pharmacoepidemiology


Purposes of Research


Before selecting a particular study design, it is important to consider the general goal of performing a given research study. It can be useful to categorize a study as serving one of three general purposes: description, identification/exploration of associations, or determination of causal relationships (Table 3-1). Because certain study designs may be better suited than others for a given research purpose, identifying what is expected from the standpoint of the research objective can help in guiding the selection of an appropriate study design. For example, if the goal is to identify potential risk factors for a given outcome, selecting a study design that merely describes the occurrence of the outcome will be of little value.

Table Graphic Jump Location
Table 3-1. General Purposes of Research and Examples.

Another way of conceptualizing the purpose of research is to determine whether one wants to develop potential hypotheses (i.e., hypothesis generation) or to formally test hypotheses that were previously developed (i.e., hypothesis testing). The traditional epidemiologic designs (e.g., cohort and case-control) are useful in allowing a researcher to develop hypotheses. The process of formally testing a hypothesis is aimed at making some causal statement (e.g., taking drug X will cause a reduction in blood pressure) and is frequently the underlying purpose of conducting research.1 Some sort of interventional study, such as a randomized controlled trial or a quasi-experiment, is usually considered necessary to test a hypothesis formally and arrive at a causal conclusion; however, advances in statistical techniques have increased the strength of causal statements from some observational study designs.2 A more formal discussion about principles of causality is provided in Chapter 6.


Principles of Study Design


Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessPharmacy Full Site: One-Year Subscription

Connect to the full suite of AccessPharmacy content and resources including 30+ textbooks such as Pharmacotherapy: A Pathophysiologic Approach and Goodman & Gilman's The Pharmacological Basis of Therapeutics, high-quality videos, images, and animations, interactive board review, drug and herb/supplements databases, and more.

$595 USD
Buy Now

Pay Per View: Timed Access to all of AccessPharmacy

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.