Transcutaneous Electrical Nerve Stimulation (TENS) could offer a non-drug form of pain relief, but there is no consensus regarding its effectiveness for chronic musculoskeletal pain or chronic low back pain. A recent review of previous trial methodology identified significant problems with low treatment fidelity. There is little information available to inform the development of a pragmatic implementation design for a TENS evaluation. The aim of this study was to explore the experiences of secondary care Pain Clinic patients with expertise in using TENS to manage chronic musculoskeletal pain. These key informants were selected as they had the potential to generate knowledge which could inform research design and clinical practice. A qualitative method using individual semi-structured interviews with open questions was selected for its capacity to generate rich data. Semi-structured interviews were conducted with nine patients (6 women). Thematic analysis was used as the primary data analysis method, and this was enhanced by a case level analysis of the context and processes of TENS use of each individual. Data analysis indicated that patients learned to address a range of problems in order to optimise TENS use. Patients may need to personalise the positioning of electrodes, and the TENS settings, and to re-adjust these over time. Patients learned to use TENS in a strategic manner, and the outcomes of each strategy varied.
The findings indicated that a pragmatic TENS evaluation may need to incorporate a learning phase to allow patients to optimise this complex pattern of TENS usage, and evaluation may need to be sensitive to the outcomes of strategic use. These findings also have implications for clinical practice.