Min Huang, PT, PhD, NCS

1. PTP 661Evidence about interventionscritically appraise the quality and applicability of an Intervention research study Min Huang, PT, PhD, NCS

2. Applicability

3. Determining Applicability of an Intervention Study • Start from a specific patient or a more general question about types of patients with the shared problem • Search for the literature • Use PICO analysis to identify the search terms • e.g. “For a 17-year-old swimmer with neck pain, is a combination of manual therapy and exercise effective for reducing pain and improving function?”

4. Determining Applicability of an Intervention Study • Q1: Is the study’s purpose relevant to my clinical question? • Read the abstract • Q2: Is the study population (sample) sufficiently similar to my patient? • To justify whether my patient would respond similarly to the population • Q3: Are the inclusion and exclusion criteria clearly defined, and would my patient qualify for the study? Is the treatment feasible in my clinic?

5. Determining Applicability of an Intervention Study • Q4: Are the intervention and comparison/ control groups receive a realistic intervention? • Q5: Are the outcome measures relevant to the clinical question and were they conducted in a clinically realistic manner? • Bottom line is to …… • weigh similarities and differences between the study participants and your patient • the intervention proposed in the study and the feasibility of this intervention for you and your patient

6. Quality and Results

7. Determining Quality of an Intervention Study • Q1: Were the participants randomly assigned to intervention groups? • RCT is the gold standard of research design for intervention studies • RCT is designed to evaluate the efficacy of an intervention • Efficacy: test-tube, ideal condition • Effectiveness: typical clinical conditions

8. Practice-Based Evidence Study Design for Comparative Effectiveness Research • Although randomized controlled trials (RCTs) are important to confirm whether a new treatment causes an effect, they are unlikely to discover combinations of interventions or practices that are effective and efficient in routine care. • PBE study is a type of observational study • often utilizes existing data from medical records • can uncover better practices more quickly than RCTs Horn 2007, http://www.effectivehealthcare.ahrq.gov/repFiles/MedCare/s50.pdf

9. Determining Quality of an Intervention Study • Q7: Is the sampling procedure (recruitment strategy) likely to minimize bias? • Sample size and study power • Recruiting a study sample • ALL patients from selected clinics vs. SOME patients referred from multiple clinics • Q8: Are all participants who enter the study accounted for? • Intention to treat (ITT)?

10. Determining Quality of an Intervention Study • Q9: Was blinding optimized in the research design? • Evaluator • Participants • Therapists • Q10: Aside from the treatment, were groups treated equally?

11. Interpreting Results of an Intervention Study • Q11: Were participants similar at the baseline? • Q12: Were outcome measures reliable and valid? • Q13: Were C.I., descriptive and inferential statistics (p values) reported and applied to the results?

12. Clinical Bottom Line

13. Summarizing the Clinical Bottom Line of an Intervention Study • Q13: Was there a treatment effect? If so, was it clinically relevant? • Change on a measure that has value to the patient • Change of a magnitude that will make a real different in the patient’s life • Effect size • e.g. Cohen’s d • Large= >0.8; Medium= 0.5-0.8; Small= 0.2-0.5 • Number Needed to Treat (NNT) • Minimally Clinically Important Difference (MCID)

14. Figure 12-2: Influence of Group Variability on Effect Size Compare absolute effect size and standardized effect size between the groups

15. Example: NNT • NNT = 2. For every two smokers who quit, one life is saved. • Which intervention is more effective? • NNT = 7. hot pack + interferential • NNT = 3. education + core stabilization (better, need to only treat 3 to save someone)