Abstract Details

This study aims to develop a patient-centered assessment measure to evaluate severity of muscle cramps.

Cramp frequency has been used most commonly as a primary outcome measure in muscle cramp trials. This may not capture the entire cramp experience, and a validated, patient-centred assessment scale is needed.  We previously interviewed patients to understand the cramp experience, to guide item generation and scaling (content validity).  We are currently testing construct validity and reliability of the measure.

We are enrolling patients ≥18 years-old, experiencing idiopathic muscle cramps or cramps associated with pregnancy, polyneuropathy, amyotrophic lateral sclerosis, hemodialysis, cirrhosis, diabetes, myasthenia gravis (MG) and Parkinson’s Disease. To assess test-retest reliability, the patients are administered the measure at baseline and 2 weeks after the first visit. Construct validity will be tested through correlations between the new measure and the Epworth Sleepiness Scale, Muscle Stiffness Index, Beck Depression Inventory, Pain Impact ASCQ Short Form, Sleep Impact ASCQ Short Form, and SF-6D utility scores.

To date, 16 patients with idiopathic cramps, cramps associated with MG and neuropathy have been enrolled. Mean age is 67.7 and 6(38%) are women. The mean score on the cramp measure is  20.1 out of a maximum of 46, with a range of scores identified across the cramp characteristics, sleep and daytime interference and mental health domains of the measure. Mean SF-6D Utility score was 0.66, Beck’s Depression score 32.0, pain impact score 47.3, stiffness impact score 54.2 and Epworth score 9.1. 

Patients to date show high levels of pain and stiffness and show a good range of responses across the various domains in our novel, patient-reported cramp scale. The final results of the validation of the score are expected at time of presentation.