Measuring coping in people with amyotrophic lateral sclerosis using the Coping Index-ALS: A patient derived, Rasch compliant scale

Abstract

OBJECTIVE: The progressively disabling and terminal nature of ALS/MND imposes major coping demands on patients. We wished to improve the psychometric properties of our previously published MND-Coping Scale, so that parametric analyses were valid, and to make it simpler for patients to complete and clinicians to score. METHODS: After a new qualitative analysis of 26 patients with ALS/MND, the draft Coping Index-ALS (CI-ALS) was administered to 465 additional patients, alongside COPE-60, General Perceived Self Efficacy scale, and WHOQOL-BREF. Validity of the CI-ALS was assessed using the Rasch model. External validity was checked against comparator measures. RESULTS: Thirteen centres contributed 465 patients, mean age 64.9 years (SD 10.8), mean disease duration 28.4 months (SD 37.5). The CI-ALS-Self and CI-ALS-Others both satisfied Rasch model expectations and showed invariance across age, gender, marital status and type of onset. Expected correlations were observed with comparator scales. A nomogram is available to convert the raw scores to interval level measures suitable for parametric analysis. CONCLUSIONS: Coping abilities in ALS/MND can now be measured using a simple 21 item self-report measure, offering two subscales with a focus of 'coping by self ' and 'coping with others'. This allows clinicians to identify individuals with poor coping and facilitates research on interventions that may improve coping skills.