Muscle Cramp Rate, Severity, and Burden in Maintenance Hemodialysis Patients: A Yearlong Multicenter Quality Improvement Initiative.

KEY POINTS: Identifying patients who cramp frequently over time is crucial for designing intervention studies to prevent cramping. One in five patients receiving hemodialysis reported muscle cramps every 4 weeks posing significant burden, although only one in eight patients cramped frequently In addition, population-based interventions are needed to address the high proportion of patients who are bothered by occasional cramps.

BACKGROUND

Cramps are common in patients on dialysis, yet data on prevalence over time and patient burden are lacking. This quality improvement initiative evaluated the prevalence and natural history of muscle cramps to provide clinicians with baseline understanding of the magnitude and scope of cramping in patients on hemodialysis.

METHODS

A recurring three-question cramps questionnaire with a 1-week recall period was embedded in routine care for patients on maintenance hemodialysis over five diverse, geographically distributed outpatient clinics to determine occurrence rate, pain severity, and burden from muscle cramps. This was repeated every 4 weeks during 2024. Prevalent patients completing ≥3 questionnaires were categorized as never-crampers, occasional crampers (<50% of responses with cramps), and frequent crampers (≥50% with cramps). The association between concurrent pain severity and bother scores (each ranging from 0 to 10) and changes in these scores were compared using linear regression.

RESULTS

There were 420 patients who completed a median of nine (interquartile range, 7-11) questionnaires. Among this cohort, 159 (38%) never reported cramps, 208 (49%) reported occasional cramps, and 53 (13%) reported frequent cramps. Although 62% reported cramps at least once, on average, 19% reported cramps every 4-week period (range 11%-25%). Most patients (69%) reported at least one cramp episode as moderate to severely painful while 60% reported cramping as moderate to extremely bothersome. Pain and bother scores for the same week correlated (0.72, P < 0.001). Between consecutive questionnaires, each one-point increase in maximal pain score associated with a 0.74 increase in bother score ( P < 0.001).

CONCLUSIONS

Surveys done every 4 weeks showed that one in five patients on hemodialysis report muscle cramps with significant burden, although only one in eight cramp frequently. Although patients who cramp frequently may be appropriate targets for initial intervention trials to prevent cramps, additional interventions could address the high proportion of patients who are bothered by occasional cramps.