Patient Perspectives of Skeletal Muscle Cramping in Dialysis: A Focus Group Study

KEY POINTS: This first step demonstrated content validity for a patient-reported outcome measure for skeletal muscle cramping in dialysis. This work lays the foundation for developing a patient-reported outcome measure for regulatory use to assess skeletal muscle cramping in people receiving dialysis. BACKGROUND: Skeletal muscle cramping is a common, painful, and debilitating symptom experienced by people receiving dialysis. Neither a standardized, patient-endorsed definition of skeletal muscle cramping nor full understanding of patients' perspectives of skeletal muscle cramping exist. We conducted focus groups, within a Kidney Health Initiative (KHI) project, to elicit skeletal muscle cramping experiences of people receiving dialysis as the basis for patient-reported outcome measure (PROM) development. METHODS: Eligible participants (English-speaking adults aged 18–85 years treated by dialysis and a skeletal muscle cramping episode within 30 days) were purposively recruited from a panel (L&E Research) of people receiving dialysis at home or in-center. Standard qualitative methods were used to conduct virtual 90-minute sessions discussing the following: skeletal muscle cramping clinical characteristics, participants' skeletal muscle cramping experiences, and feedback on a draft skeletal muscle cramping definition and a patient-facing conceptual model developed by the KHI project workgroup. We used qualitative thematic analysis. RESULTS: There were 20 diverse participants in three focus groups. Universally experienced skeletal muscle cramping attributes differed by dialysis setting in onset, worst pain rating, duration, and timing. Variably experienced attributes (applied to home and in-center dialysis) were gross and fine motor effect, sleep disruption, mood-related themes of fear, and annoyance/frustration/irritability. Avoidance/adaptive behaviors included reluctance or avoiding movement, adjusting what they ate or drink (e.g., yellow mustard, pickles, pickle juice, and tonic water), heat application, massage, and cannabidiol use. The skeletal muscle cramping definition was endorsed, and insightful suggestions for conceptual model were collected. CONCLUSIONS: This qualitative study of in-center and home patients' skeletal muscle cramping experiences identified universally and variably experienced attributes. The patient-endorsed skeletal muscle cramping definition can serve as a standard for assessment. These results provide the foundation to develop a PROM for regulatory use with people receiving maintenance dialysis who experience skeletal muscle cramping.