PAPER

The MS Symptom and Impact Diary (MSSID): psychometric evaluation of a new instrument to measure the day to day impact of multiple sclerosis

J Greenhalgh¹, H Ford², A F Long¹, K Hurst³

¹ Health Care Practice R&D Unit, University of Salford, Allerton Building, Frederick Road, Salford M6 4WT, UK
² United Leeds Teaching Hospital’s Trust, Beckett Street, Leeds LS9 7TF, UK
³ Nuffield Institute for Health, University of Leeds, 71–75 Clarendon Road, Leeds LS2 9PL, UK

Objectives: This study aimed to develop further a diary originally devised to measure the impact of multiple sclerosis (MS) as part of a cost utility study of beta interferon, and to evaluate its reliability, validity, and responsiveness in an outpatient sample of people with MS.

Methods: The original diary was further developed using qualitative and quantitative methods to ensure that it addressed the views of people with MS. The psychometric properties of the MS Symptom and Impact Diary (MSSID) were evaluated in a sample of 77 people who completed the MSSID daily for 12 weeks. Internal and test–retest reliability, discriminant and convergent validity, and responsiveness were assessed using traditional psychometric methods.

Results: The MSSID formed three, internally consistent scales that measured mobility, fatigue, and the overall impact of MS. The test–retest reliability of the mobility scale was adequate for individual comparisons (ICC>0.90) and the fatigue and overall impact scales were adequate for group comparisons (ICC>0.70). The MSSID was able to distinguish between clinical groups depending on clinical course, indoor ambulation status, and relapse status. It demonstrated associations with other single point instruments in the expected direction. Compared with single point instruments, its responsiveness was similar or better, especially in detecting short term improvements in functioning.

Conclusions: The MSSID may provide a useful complement to currently available instruments to measure the outcomes of MS within clinical trials. Further research is needed to explore its feasibility in the context of a randomised controlled trial and its utility for clinicians.

Keywords: multiple sclerosis; psychometrics; diary

Abbreviations: BI, Barthel Index; MS, multiple sclerosis; LHS, London Handicap Scale; Leeds MS quality of life scale; MSIS-29, MS Symptom and Impact Scale-29; MSSID, MS Symptom and Impact Diary

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Simeoni, M., Auquier, P., Fernandez, O., Flachenecker, P., Stecchi, S., Constantinescu, C., Idiman, E., Boyko, A., Beiske, A., Vollmer, T., Triantafyllou, N., O'Connor, P., Barak, Y., Biermann, L., Cristiano, E., Atweh, S., Patrick, D., Robitail, S., Ammoury, N., Beresniak, A., Pelletier, J. on behalf (2008). Validation of the Multiple Sclerosis International Quality of Life questionnaire. Mult Scler 14: 219-230 [Abstract]  
• Lily, O, McFadden, E, Hensor, E, Johnson, M, Ford, H (2006). Disease-specific quality of life in multiple sclerosis: the effect of disease modifying treatment. Mult Scler 12: 808-813 [Abstract]  
• Beaumont, J G (2004). The MS symptom and impact diary (MSSID): psychometric evaluation of a new instrument to measure the day to day impact of multiple sclerosis. J. Neurol. Neurosurg. Psychiatry 75: 526-527 [Full Text]