Type of Clinical Question and Study Design Heather L. Bowyer, DC, CCSP

Types of Clinical Questions Therapy/Intervention –Effect on patient outcomes Diagnosis/Diagnostic test –Power of a test to identify those with and without a target condition Prognosis/Prediction –A patient’s future course Harm –Effect of harmful agents on patient outcomes (including therapies) JAMA Evidence - User's Guide to the Medical Literature

Therapy/Intervention Randomized Control Trial (RCT) ELIGIBLE PATIENTS INTERVENTION Positive Outcome Negative Outcome CONTROL Positive Outcome Negative Outcome Random Assignment

Therapy/Intervention Clinical Question: –Is spinal manipulation more beneficial than home exercise advice at reducing pain in patient’s with neck pain? In neck pain P), does spinal manipulation I) compared to home exercise advice C) improve patient’s pain O)? Study Design: RCT

Therapy/Intervention Randomized Control Trial (RCT) NECK PAIN SPINAL MANIPULATION Pain Reduction No Reduction in Pain HOME EXERCISE ADVICE Pain Reduction No Reduction in Pain Random Assignment

Diagnosis/Diagnostic Test Controlled Trial ELIGIBLE PATIENTS HAVE DISEASE (TARGET CONDITION) Positive Test Negative Test DO NOT HAVE DISEASE Positive Test Negative Test Gold Standard Test (Truth) Diagnostic Test Administered

Diagnosis/Diagnostic Test Clinical Question: –How effective is abdominal palpation at detecting a AAA? In patients at risk for AAAP) is abdominal palpation I) compared with diagnostic ultrasound C) accurate in diagnosing AAA O)? Study Design: Controlled Trial

Diagnosis/Diagnostic Test Controlled Trial AT RISK FOR AAA AAA (TARGET CONDITION) Positive Test Negative Test DO NOT HAVE AAA Positive Test Negative Test Gold Standard Test DIAGNOSTIC US ABDOMINAL PALPATION

Prognosis/Prediction Case Control Study PATIENTS IDENTIFIED Experience target outcome Do not experience target outcome Time

Prognosis/Prediction Clinical Question: –What is the risk of recurrent hamstring injury in an athlete? In an athlete P) how does a primary hamstring injury I) compared to N/A C) influence/predict re- injuryO)? Study Design: Case Control

Prognosis/Prediction Case Control Study ATHLETE WITH PRIMARY HAMSTRING INJURY RE-INJURYNO RE-INJURY Time

Harm Prospective Cohort Study ELIGIBLE PATIENTS EXPOSURE TO POTENTIAL HARM Positive Outcome Negative Outcome NOT EXPOSED Positive Outcome Negative Outcome Exposure by choice or happenstance

Harm Clinical Question: –How does smoking effect the survival rate of a patient previously diagnosed with prostate cancer? Are men with prostate cancer P) who smoke tobacco I) compared with those who do not smoke tobacco C) at increased risk of death O)? Study Design: Cohort Study

Harm Prospective Cohort Study MEN WITH PROSTATE CA SMOKE TOBACCO Positive Outcome Negative Outcome NON-SMOKER Positive Outcome Negative Outcome Exposure by choice or happenstance

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