title: Implementation fidelity of self-administered transcutaneous electrical nerve stimulation (TENS) in patients with chronic back pain: an observational study.
abstract: OBJECTIVE
  The efficacy of transcutaneous electrical nerve stimulation (TENS) for pain relief has not been reliably established. Inconclusive findings could be due to inadequate TENS delivery and inappropriate outcome assessment. Electronic monitoring devices were used to determine patient compliance with a TENS intervention and outcome assessment protocol, to record pain scores before, during, and after TENS, and measure electrical output settings.
  
  
  METHODS
  Patients with chronic back pain consented to use TENS daily for 2 weeks and to report pain scores before, during, and after 1-hour treatments. A ≥ 30% reduction in pain scores was used to classify participants as TENS responders. Electronic monitoring devices "TLOG" and "TSCORE" recorded time and duration of TENS use, electrical settings, and pain scores.
  
  
  RESULTS
  Forty-two patients consented to participate. One of 35 (3%) patients adhered completely to the TENS use and pain score reporting protocol. Fourteen of 33 (42%) were TENS responders according to electronic pain score data. Analgesia onset occurred within 30 to 60 minutes for 13/14 (93%) responders. It was not possible to correlate TENS amplitude, frequency, or pulse width measurements with therapeutic response.
  
  
  CONCLUSIONS
  Findings from TENS research studies depend on the timing of outcome assessment; pain should be recorded during stimulation. TENS device sophistication might be an issue and parameter restriction should be considered. Careful protocol design is required to improve adherence and monitoring is necessary to evaluate the validity of findings. This observational study provides objective evidence to support concerns about poor implementation fidelity in TENS research.
authors: *Department of Health Sciences, Leicester Royal Infirmary †Department of Health Sciences, Academic Unit, University of Leicester, Leicester ‡Faculty of Health and Social Sciences, Leeds Metropolitan University, Leeds, UK.
authors: Edward J
authors: EJ
authors: Pallett
authors: Patricia
authors: P
authors: Rentowl
authors: Mark I
authors: MI
authors: Johnson
authors: Paul J
authors: PJ
authors: Watson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001416:Back Pain / Q000175:diagnosis / Q000628:therapy*; D059350:Chronic Pain / Q000175:diagnosis / Q000628:therapy*; D055615:Electrical Equipment and Supplies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010147:Pain Measurement / Q000295:instrumentation / Q000379:methods; D010349:Patient Compliance; D013997:Time Factors; D004561:Transcutaneous Electric Nerve Stimulation / Q000295:instrumentation / Q000379:methods; D055815:Young Adult