Lecture 1

Question 1

Experimental Research

Answer 1

Variables are subject to manipulation by the investigator. In clinical research, this involves ASSIGNMENT to treatment status

Question 2

Observational Research

Answer 2

Investigator(s) “observe” what occurs naturally, i.e. in real-world settings. Treatment status is based on patient/system factors, not assigned.

Question 3

Intervention Research

Answer 3

Establishes EFFICACY or EFFECTIVENESS as well as safety, of an intervention in a specific clinical population

Question 4

Diagnosis Research

Answer 4

Validates a clinical diagnostic test against an established (and valid) “Gold standard” for that diagnosis.

Question 5

Prognosis Research

Answer 5

Assesses demographic, behavioral and clinical characteristics that predict disease, or other outcomes of interest

Question 6

Randomized Controlled Trials

Answer 6

• Most rigorous EXPERIMENTAL research design
• Useful ONLY for research on interventions
• Subjects are randomly assigned to an intervention (or not)
• Blinding of intervention may be applied to participants, clinicians etc.
• Timing of data collection is PROSPECTIVE

Question 7

Cohort Studies

Answer 7

• Most rigorous OBSERVATIONAL research design
• Study of “naturally” occurring groups
• Subjects classified by exposure status and followed forward in time for outcome
• Useful for cause of disease and prognosis, diagnosis/screening tests, interventions
• Timing may be prospective or retrospective

Question 8

Case-Control Studies

Answer 8

• Outcome (disease) is rare or unusual
• Subjects initially classified by outcome status
• Exposures are already occurred or did not occur
• Useful for research on etiology (cause of disease)/prognosis
• Usually NOT for intervention or diagnosis research
• Timing is always retro

Question 9

Cross-Sectional Studies

Answer 9

• Exposure and outcome measured at same time
• Useful for study of disease burden within a community (prevalence)
• May be used in diagnosis research (concurrent validity)
• Utility for research on intervention, etiology, prognosis is limited
• Timing is neither prospective or retro

Question 10

Systematic Reviews

Answer 10

• Examine multiple primary studies addressing a specific clinical question
• I.E. intervention effectiveness, diagnostic test accuracy, prognostic factor
• Included primary studies are rigorously appraised to assess credibility
• Data from individual studies is combined to produce more powerful summary findings (meta-analysis)

Question 11

Clinical practice guidelines, evidence syntheses, critically appraised topics

Answer 11

• Organizations that summarize findings for a specific clinical issue
• May include systematic reviews or appraisals or systemic reviews/primary studies