Considerations for evidence based practice in electrotherapy

1. Considerations for evidence based practicein electrotherapy Gilbert Madriaga, PTRP Department of Physical Therapy UP-CAMP

2. Objectives • Discuss considerations in the evidenced-based practice in electrotherapy • Explain how factors that may affect external validity of clinical trials in electrotherapeutic agents. • Explain factors that limit the quality of evidence in electrotherapy

3. Perceptions • What are your perceptions about the quality of existing studies in electrotherapy? • Be honest 

4. Clinical trials • Number of clinical trials in electrotherapy • 2005: approx 700 clinical trials • 2010: 2374 clinical trials (EPA’s) [PEDro]

5. Is there evidence? • “no evidence for its use” • “judiciously prune deadwood” • “no-one uses it anymore” • (Crosbie, 2002) • Limited high quality studies to answer many questions about EPA utilization

6. On the positive note • High quality systematic reviews supporting the use of electrophysical agents • Therapeutic ultrasound for venous leg ulcers • (Flemming and Cullen, 2002) • Transcutaneous electrical nerve stimulation for knee osteoarthritis • (Osiri et al 2000)

7. Factors that limit quality of evidence What factors limit the quality of evidence in the EPA literature? • obtaining sufficient and homogenous subjects • Mixed etiology • randomization and stratification • subject and assessor blinding • unanswerable research questions • Inappropriate data collected resulting to unanswered questions • expecting improbable benefits from using a modality

8. Factors that limit quality of evidence What factors limit the quality of evidence in the EPA literature? • Dosage • Intensity, frequency, pulsed or continuous • inter-patient variation • tissue depth and distribution of lesion • Amplitude window or strength window • Frequency window

11. Factors that limit quality of evidence What factors limit the quality of evidence in the EPA literature? • Method of application • accurate targeting of a lesion is fundamental to whether an • Just placing TENS electrodes in the general region of a painful joint is not sufficient • (Laakso, Robertson & Chipchase, 2004).

12. All possible permutations of doses and methods of administration have not yet been subjected to clinical trials • Trials may not yet have investigated the optimal modes for administering interventions • Future clinical trials may identify optimally effective modes of administration

13. External validity • Are the subjects in the study similar to the patients to whom I wish to apply the study’s findings? • Are the outcomes useful? • Were interventions applied appropriately?

14. External validity Are the subjects in the study similar to the patients to whom I wish to apply the study’s findings? • Making inferences based on the outcomes in the target population • Similar enough? • Effect modifiers • e.g. US as pre-stretch modality • Estimate of the average effect of the intervention in the whole population

15. External validity Are the outcomes useful? • What’s important to patient? • Consider if the trial measures outcomes that matter to patients. • Health related quality of life • Surrogate measure • Proxy to the construct of interest • E.g. muscle contraction as an outcome measure for the FES

16. External validity Were interventions applied appropriately? • Inefficient to examine all possible ways to apply the therapy in randomized trials • If theory provides clear guidelines • No basis to support clinical trials with dubious parameters • If theory is unclear • Consider using RCT?

17. Trial designs Trial designs and inferences • Intervention with no intervention, • Standard intervention plus a new intervention with standard intervention alone, • Two interventions

18. Trial designs intervention with no intervention, • how much more effective EPA is than no intervention

19. Trial designs Standard intervention plus a new intervention with standard intervention alone, • Effect of 2 modalities • May be different from the latter if there is interaction between co-interventions

20. Trial designs Two interventions • Direct comparison between two interventions

21. Consider whether the intervention was administered in a theoretically reasonable way • Disregard clinical trials that utilizes interventions that are inappropriate. • If there is uncertainty about how best to apply a therapy • accept the findings of the trial, even if it is different from how we plan to use it • until better evidence becomes available.

23. PEDro score 6/10 • Eligibility criteria: Yes • Random allocation: Yes • Concealed allocation: No • Baseline comparability: Yes • Blind subjects: Yes • Blind therapists: No • Blind assessors: Yes • Adequate follow-up: No • Intention-to-treat analysis: No • Between-group comparisons: Yes • Point estimates and variability: Yes

26. Assignment! Read the following journal and explain the factors which might affect the internal and external validity of the study. Date of submission: 1 February 2010 Type written, one page only

28. “lack of experimental evidence is not evidence of ineffectiveness but should alert us to the need to direct research efforts to test unsubstantiated interventions” • (Research Committee APA Victorian Branch, 1999)

29. References • Gursel, Y., et al. (2004). Adding Ultrasound I the management of soft tissue disorders of the shoulder: A randomized placebo-controlled trial. Physical Therapy, 84, 336, 343 • Herbert, R., Jamtvedt, G., Mead, J., & Hagen, K. B. (2005). Practical evidence-based physiotherapy.  London: Elsevier Limited. • Laakso E., Robertson V., & Chipchase L. (2002). The place of electrophysical agents in Australian and New Zealand entry-level curricula: Is there evidence for their inclusion? Australian Journal of Physiotherapy, 48, 251-254