Searching for Evidence in Healthcare

Jan 26, 2025

Evidence-Based Process: Searching for Information

Introduction

  • The lecture delves into Step 2 of the evidence-based process: Searching
  • Step 1 involved developing a well-built clinical question using PICO
  • Searching involves various methods and sources, including:
    • Google (basic search)
    • Databases such as CINAHL and PubMed
  • Importance of reliability and quality of information

Types of Clinical Questions

  • Identify the question type to find the best study:
    1. Therapy or Treatment
      • Example: Ways for smokers to quit smoking
    2. Prognosis
      • Example: Impact of being born premature on learning
    3. Diagnosis
      • Example: Comparing CT scans with other clinical findings for intracranial hemorrhage
    4. Harm or Etiology
      • Example: Risk of brain cancer from cell phone use

Study Types and Evidence Quality

  • Understanding study types is crucial for evaluating evidence
  • Studies are ranked from weakest to strongest in terms of evidence:

1. Case Reports and Case Series

  • Focus on individual or few cases
  • Useful for rare diseases but not generalizable

2. Case Control Studies

  • Compare patients with and without a disease retrospectively
  • Example: Thalidomide babies study

3. Cohort Studies

  • Follow groups (cohorts) over time prospectively
  • Example: Framingham Heart Study

4. Prospective Blind Comparison to a Gold Standard

  • Compares new diagnostic tools to the gold standard

5. Randomized Controlled Trials (RCTs)

  • Assign participants to control or experimental groups
  • Considered the cornerstone of health sciences research

6. Systematic Reviews

  • Comprehensive, unbiased review of all relevant studies
  • Distinct from literature reviews
  • Example: Cochrane Database of Systematic Reviews

7. Meta-Analysis

  • A step further than systematic reviews, applying statistical analysis
  • Combines studies to form a comprehensive evaluation

Determining Study Type in Articles

  • Check title, abstract, or methods section to identify study type

Conclusion

  • Review of main question types and study types
  • Preview of next lecture on levels of evidence and finding evidence-based information
  • Lighthearted conclusion with mention of an adorable baby pig