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Transcutaneous Electrical Nerve Stimulation for Endometriosis-related Chronic Pain

Not Applicable
Recruiting
Conditions
Endometriosis-related Pain
Interventions
Device: Transcutaneous electrical nerve stimulation (TENS)
Other: Conventional analgesic treatment
Registration Number
NCT05152264
Lead Sponsor
Göteborg University
Brief Summary

The study evaluates the effect of TENS (transcutaneous electrical nerve stimulation) as add-on treatment compared with conventional analgesic treatment in patients with endometriosis-related chronic pain. Patients with frequent pain and high pain intensity will be randomized to additional treatment with TENS or conventional treatment for 8 weeks to evaluate the acute effects of TENS treatment (n=40). Patients with endometriosis-related pain that is not frequent or without high pain intensity constitute an external control group. All patients in the study will receive TENS treatment for a total of 16 weeks, for evaluation of long-term effects of TENS treatment.

Detailed Description

Endometriosis affects approximately one in ten women of childbearing age and may involve both acute pain related to the menstrual cycle and chronic pain. Usual analgesic therapy is often inadequate and/or involves unacceptable side effects and risks with long-term use. Transcutaneous electrical nerve stimulation (TENS) is a patient controlled treatment for pain relief with few side-effects. To date there is limited knowledge of how TENS treatment should be carried out for optimal pain relief in this patient group. The aim of the study is asses the effect of TENS as add-on treatment compared with conventional analgesic treatment in patients with endometriosis-related chronic pain. Patients with frequent pain and high pain intensity (≥ 4 according to Numeric Rating Scale, NRS) will be randomized to additional treatment with TENS or conventional treatment for 8 weeks in order to evaluate the acute effects of TENS treatment (n=40). Patients with endometriosis-related pain that is not frequent or without high pain intensity constitute an external control group. All patients in the study will receive TENS treatment for a total of 16 weeks, for evaluation of long-term effects of TENS treatment in chronic endometriosis-related pain. Prior to start of TENS treatment, all patients receive education on chronic endometriosis-related pain and TENS treatment. Study participants will be asked to participate in a qualitative follow-up within the study including a semi-structured individual interview (n=10-15) before intervention and a semi-structured focus group (n=9-15) interview after completion of TENS treatment.

Recruitment & Eligibility

Status
RECRUITING
Sex
Female
Target Recruitment
40
Inclusion Criteria
  • Age ≥18 years
  • Consents to participation in the study
  • Verified endometriosis (by laparoscopy or ultrasound).
  • Chronic endometriosis-related pain (> 3 months), available for TENS treatment
  • Functioning, stable endometriosis-specific hormonal drug therapy. The endometriosis-specific drug therapy must be unchanged for the last 3 months and no gynecological surgical procedures for the treatment of endometriosis are planned during the next 7 months (during study participation). The endometriosis-specific drug therapy does not refer to analgesic therapy for symptom relief of endometriosis-related pain.
Exclusion Criteria
  • Patient with inability to understand and use written and spoken Swedish
  • Patient with pacemaker and/or ICD or other electronic implants
  • Patient with impaired sensation over the painful area
  • Malignant disease with an expected survival <12 months
  • Alcohol or substance abuse
  • Serious untreated psychiatric illness and/or psychological condition that is the primary determinant of the patient's condition
  • Participating in another intervention study with possible impact on current study outcome measures
  • Patient who is using >90 morphine equivalents/day
  • Patient who is electro-acupuncture
  • Pregnancy

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
External control groupTranscutaneous electrical nerve stimulation (TENS)Patients with endometriosis-related pain that is not frequent or without high pain intensity (\< 4 according to Numeric Rating Scale, NRS) constitute an external control group. The patients are treated with transcutaneous electrical nerve stimulation as add-on treatment in addition to conventional analgesic treatment. Treatment with transcutaneous electrical nerve stimulation (TENS) during 16 weeks.
TENS (transcutaneous electrical nerve stimulation)Transcutaneous electrical nerve stimulation (TENS)Patients with endometriosis-related chronic frequent pain and high pain intensity (≥ 4 according to Numeric Rating Scale, NRS) randomized to transcutaneous electrical nerve stimulation as add-on treatment in addition to conventional analgesic treatment. Treatment with transcutaneous electrical nerve stimulation (TENS) during 16 weeks.
Conventional analgesic treatmentConventional analgesic treatmentPatients with endometriosis related chronic frequent pain and high pain intensity (≥ 4 according to Numeric Rating Scale, NRS) randomized to conventional analgesic treatment for 8 weeks. After 8 weeks the patients are treated with transcutaneous electrical nerve stimulation (TENS) during 16 weeks.
Primary Outcome Measures
NameTimeMethod
Pain intensity8 weeks after randomization

Pain intensity according to numeric rating scale (score from 0 to 10, where 0 is described as "no pain" and 10 as "worst pain imaginable") with regard to endometriosis-related chronic pain

Secondary Outcome Measures
NameTimeMethod
Self-assessed physical activity16 weeks after start of TENS treatment

Minutes of physical activity per week (physical exercise and daily exercise) and minutes of sedentary behaviour per week.

Pain intensity16 weeks after start of TENS treatment

Pain intensity according to numeric rating scale (score from 0 to 10, where 0 is described as "no pain" and 10 as "worst pain imaginable") with regard to endometriosis-related chronic pain

Physical activity16 weeks after start of TENS treatment

Minutes of physical activity per week at moderate and vigorous intensity physical activity (MVPA), minutes of sedentary behaviour (SED) assessed by accelerometry

General Self-Efficacy Scale16 weeks after start of TENS treatment

The General Self-Efficacy Scale is a 10-item psychometric scale that is designed to assess optimistic self-beliefs to cope with a variety of difficult demands in life, Likert scale (1= Not at all true 2= Hardly true 3= Moderately true 4= Exactly true)

Days of sick-leave16 weeks after start of TENS treatment

Number of days of sick-leave

Consumption of analgetics16 weeks after start of TENS treatment

Consumption of primary and secondary analgetics including opioid consumption in morphine equivalent doses

Health Related Quality of Life (HRQL) according to SF3616 weeks after start of TENS treatment

Assessed with RAND Short Form 36 (SF36). The 36 items in the questionnaire are grouped into eight subscale scores: physical functioning, role limitations caused by physical problems, bodily pain, general health, energy/vitality, social functioning, role limitations caused by emotional problems and mental health. The subscale scores range from 0-100, the higher score, the better health related quality of life.

Health Related Quality of Life (HRQL) assessed with EHP 3016 weeks after start of TENS treatment

Assessed with Endometriosis Health Profile 30. The EHP score indicate the extent of self-reported ill health on each of the 5 domains measured (Pain, Control and powerlessness, Social support, Emotional well-being, Self-image). Each scale is standardised on a scale of 0 - 100, where 0 indicates the best health status through to 100 worst health status.

Change in pain intensity16 weeks after start of TENS treatment

Pain intensity according to numeric rating scale (score from 0 to 10, where 0 is described as "no pain" and 10 as "worst pain imaginable") with regard to endometriosis-related chronic pain, Likert scale (1= "worse," 2= "unchanged," 3= "slightly improved," 4= "much improved," 5 = "very much improved,"and 6= "completely improved").

Health Related Quality of Life (HRQL) assessed with EQ-5D16 weeks after start of TENS treatment

Assessed with EQ-5D-5L. The questionnaire comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems, slight problems, moderate problems, severe problems and extreme problems. The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. This decision results in a 1-digit number that expresses the level selected for that dimension. The digits for the five dimensions can be combined into a 5-digit number that describes the patient's health state.

The EQ VAS records the patient's self-rated health on a vertical visual analogue scale, where the endpoints are labelled 'The best health you can imagine' and 'The worst health you can imagine'. The VAS can be used as a quantitative measure of health outcome that reflect the patient's own judgement.

Insomnia Severity16 weeks after start of TENS treatment

Total score from the 7-item Insomnia Severity Index where total score ranges from 0-28 and higher scores indicate greater severity of insomnia.

Trial Locations

Locations (1)

Pain Centre, Department of Anaesthesiology and Intensive Care Medicine Östra, Sahlgrenska University Hospital, Region Västra Götaland

🇸🇪

Gothenburg, Sweden

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