H-Wave® Device Stimulation for Chronic Low Back Pain: A Patient-Reported Outcome Measures (PROMs) Study

INTRODUCTION

Chronic low back pain (cLBP) is a problem globally, creating a tremendous economic burden. Since conventional treatments often fail, various forms of electrical stimulation have been proposed to improve function and decrease pain. Patient-reported outcome measures (PROMs) have not been adequately reported in the electrical stimulation literature.

METHODS

A retrospective independent statistical analysis was conducted on PROMs data for users of H-Wave® device stimulation (HWDS) collected by the device manufacturer over a period of 4 years. Final surveys for 34,192 pain management patients were filtered for pain chronicity limited to 3-24 months and device use of 22-365 days, resulting in 11,503 patients with "all diagnoses"; this number was then reduced to 2711 patients with nonspecific cLBP, sprain, or strain.

RESULTS

Reported pain was reduced by 3.12 points (0-10 pain scale), with significant (≥ 20%) relief in 85.28%. Function/activities of daily living (ADL) improved in 96.36%, while improved work performance was reported in 81.61%. Medication use decreased or stopped in 64.41% and sleep improved in 59.76%. Over 96% reported having expectations met or exceeded, service satisfaction, and confidence in device use, while no adverse events were reported. Subgroup analyses found positive associations with longer duration of device use, home exercise participation, and working, whereas older age and longer pain chronicity resulted in reduced benefit. Similar analysis of the larger all-diagnoses cohort demonstrated near-equivalent positive outcomes.

CONCLUSION

Treatment outcomes directly reported by cLBP HWDS patients demonstrated profound positive effects on function and ADL, robust improvement in pain perception, and additional benefits like decreased medication use, better sleep, and improved work performance, representing compelling new evidence of treatment efficacy.

Do Electrical Stimulation Devices Reduce Pain and Improve Function?-A Comparative Review

BACKGROUND

Multiple forms of electrical stimulation (ES) potentially offer widely varying clinical benefits. Diminished function commonly associated with acute and chronic pain lessens productivity and increases medical costs. This review aims to compare the relative effects of various forms of ES on functional and pain outcomes.

METHODS

A comprehensive literature search focused on studies of commonly marketed forms of ES used for treatment of pain and improvement of function. Peer-reviewed manuscripts were categorized as "Important" (systematic review or meta-analysis, randomized controlled trial, observational cohort study) and "Minor" (retrospective case series, case report, opinion review) for each identified form of ES.

RESULTS AND DISCUSSION

Varying forms of ES have markedly different technical parameters, applications, and indications, based on clinically meaningful impact on pain perception, function improvement, and medication reduction. Despite being around for decades, there is limited quality evidence for most forms of ES, although there are several notable exceptions for treatment of specific indications. Neuromuscular electrical stimulation (NMES) has well-demonstrated beneficial effects for rehabilitation of selective spinal cord injured (SCI), post-stroke, and debilitated inpatients. Functional electrical stimulation (FES) has similarly shown effectiveness in rehabilitation of some stroke, SCI, and foot drop outpatients. H-Wave® device stimulation (HWDS) has moderate supportive evidence for treatment of acute and refractory chronic pain, consistently demonstrating improvements in function and pain measures across diverse populations. Interestingly, transcutaneous electrical nerve stimulation (TENS), the most widely used form of ES, demonstrated insignificant or very low levels of pain and functional improvement.

CONCLUSION

Ten of 13 reviewed forms of ES have only limited quality evidence for clinically significant reduction of pain or improvement of function across different patient populations. NMES and FES have reasonably demonstrated effectiveness, albeit for specific clinical rehabilitation indications. HWDS was associated with the most clinically significant outcomes, in terms of functional improvement combined with reduction of pain and medication use. More rigorous long-term clinical trials are needed to further validate appropriate use and specific indications for most forms of ES.

LEVEL OF EVIDENCE

II.

Clinical and Quality of Life Benefits for End-Stage Workers' Compensation Chronic Pain Claimants following H-Wave® Device Stimulation: A Retrospective Observational Study with Mean 2-Year Follow-Up

Previously promising short-term H-Wave^® device stimulation (HWDS) outcomes prompted this retrospective cohort study of the longer-term effects on legacy workers' compensation chronic pain claimants. A detailed chart-review of 157 consecutive claimants undergoing a 30-day HWDS trial (single pain management practice) from February 2018 to November 2019 compiled data on pain, restoration of function, quality of life (QoL), and polypharmacy reduction into a summary spreadsheet for an independent statistical analysis. Non-beneficial trials in 64 (40.8%) ended HWDS use, while 19 (12.1%) trial success charts lacked adequate data for assessing critical outcomes. Of the 74 final treatment study group charts, missing data points were removed for a statistical analysis. Pain chronicity was 7.8 years with 21.6 ± 12.2 months mean follow-up. Mean pain reduction was 35%, with 89% reporting functional improvement. Opioid consumption decreased in 48.8% of users and 41.5% completely stopped; polypharmacy decreased in 36.8% and 24.4% stopped. Zero adverse events were reported and those who still worked usually continued working. An overall positive experience occurred in 66.2% (p < 0.0001), while longer chronicity portended the risk of trial or treatment failure. Positive outcomes in reducing pain, opioid/polypharmacy, and anxiety/depression, while improving function/QoL, occurred in these challenging chronic pain injury claimants. Level of evidence: III.

H-Wave® Device Stimulation: A Critical Review

Pain treatments have historically centered on drugs, but an “opioid crisis” has necessitated new standards of care, with a paradigm shift towards multi-modal pain management emphasizing early movement, non-narcotics, and various adjunctive therapies. Electrotherapies remain understudied and most lack high-quality clinical trials, despite a desperate need for effective adjunctive options. A systematic search of human clinical studies on H-Wave^® device stimulation (HWDS) was conducted as well as a comprehensive review of articles articulating possible HWDS mechanisms of action. Studies unrelated to H-Wave were excluded. Data synthesis summarizes outcomes and study designs, categorized as pre-clinical or clinical. Pre-clinical studies demonstrated that HWDS utilizes a biphasic waveform to induce non-fatiguing muscle contractions which positively affect nerve function, blood and lymph flow. Multiple clinical studies have reported significant benefits for diabetic and non-specific neuropathic pain, where function also improved, and pain medication usage substantially dropped. In conclusion, low- to moderate-quality HWDS studies have reported reduced pain, restored functionality, and lower medication use in a variety of disorders, although higher-quality research is needed to verify condition-specific applicability. HWDS has enough reasonable evidence to be considered as an adjunctive component of non-opioid multi-modal pain management, given its excellent safety profile and relative low cost. Level of Evidence: III.