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Research Methodology: Instrumentation, Reviews, and Trials

This guide is an introduction to research methods. In it, you will find explanations of key terms; tools for finding controlled trials, research instruments, and systematic reviews; and suggestions on how to evaluate them.

Introduction

The National Library of Medicine defines a controlled trial as "[a] work that reports on a clinical trial involving one or more test treatments, at least one control treatment, specified outcome measures for evaluating the studied intervention, and a bias-free method for assigning patients to the test treatment. The treatment may be drugs, devices, or procedures studied for diagnostic, therapeutic, or prophylactic effectiveness. Control measures include placebos, active medicine, no-treatment, dosage forms and regimens, historical comparisons, etc. When randomization using mathematical techniques, such as the use of a random numbers table, is employed to assign patients to test or control treatments, the trial is characterized as a RANDOMIZED CONTROLLED TRIAL." (https://www.ncbi.nlm.nih.gov/mesh/68018848)

Finding Controlled Trials

Here we will look at how to find controlled trials using the library databases.

You can trust controlled trials to be presented with as little bias as possible, to be evidence-based, and to be peer-reviewed. They will provide you with a comprehensive investigation into the efficacy of an intervention.

This guide does not provide instructions on how to conduct your controlled trial, but rather how you can find the controlled trials others have conducted.

Searching Cochrane Database of Controlled Trials (CENTRAL) 

The Cochrane Central Register of Controlled Trials (CENTRAL) is a highly concentrated source of reports of randomized and quasi-randomized controlled trials. Most CENTRAL records are taken from bibliographic databases including PubMed and Embase, and are also derived from other published and unpublished sources, including CINAHL, ClinicalTrials.gov, and the WHO's International Clinical Trials Registry Platform.

Here are the steps to searching CENTRAL at Carlow.

  1. Navigate to the Grace Library homepage.
  2. Click on "A-Z Databases."
  3. Click on "Cochrane Central Register of Controlled Trials."
    • Please note: attempting to access Grace Library's database off campus will prompt you to enter your Carlow username and password
  4. Here you can run a search using the advanced search box and field selection drop-down.
    •  
  5. Or, you can browse the index by clicking "Indexes" at the top of the screen. This is the most efficient way to access subjects, such as Medical Subject Headings (MeSH).
    • Click "Indexes"
    • Select "MeSH Headings (Major)" from the "Browse an index" drop-down menu.
    • In the "Browse for" box, search for a subject. In this example, I am searching for "sprains and strains."
    • Click the check box next to all of the subjects you would like to browse, and click "Add."
    • This will create a search string at the top of the screen. Finally, click "Search" to see all systematic reviews that match the subjects you've selected.

Glossary

Medical Subject Headings (MeSH) - A controlled vocabulary from the National Library of Medicine used for categorizing biomedical information.