Cognitive impairment in multiple sclerosis does not affect reliability and validity of self-report health measures

Abstract

Patient self-report health measures have received increasing recognition as supplementar y outcome parameters in multiple sclerosis (MS). G iven the high prevalence of cognitive problems in this population, reliability and validity of self-report instruments in patient groups with cognitive impairment is essential, especially when using such scales longitudinally. A sample of 80 MS patients with cognitive dysfunction according to Symbol Digit Modalities Test (SDMT) score and 107 unimpaired patients were included in the analyses. Data was available from the Hamburg Q uality of Life Q uestionnaire in Multiple Sclerosis (HAQ UA MS), the Hospital A nxiety and Depression Scale (HA DS), clinical rating scores [Expanded Disability Status Scale (EDSS) and FS (Functio nal Status) scales, C A MBS (Cambridge MS Basic Score)] and objective tests of upper and lower limb function [Timed 8 Meter Walk (T8) and Nine Hole Peg Test (9HPT)). Both self-report questionnaires showed satisfactory internal consistencies and retest reliability. Pattern and magnitude of correlations with other health status measures supported the validity of both instruments. However, there was a marked discrepancy between subjective and objective measures of cognitive function. C ognitively impaired patients furthermore showed significantly higher depression and anxiety as well as lower quality of life (Q oL). The report provides evidence that Q oL and affective symptomatology can be reliably assessed in MS patients with cognitive dysfunction. The common pattern of poor correlation between self-rated and objective cognitive function thus appears to be a result of the patients’ (adaptive or maladaptive) coping mechanisms rather than being due to inaccurate measurement.

Keywords

clinical scores cognitive impairment HADS HAQUAMS multiple sclerosis objective tests reliability

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References

Kurtzke JM. Rating neurological impairment in multiple sclerosis: an expanded disability status scale . Neurology 1983; 33: 1444-1452 .

Sharrack B , Hughes RAC , Soudain S , Dunn G. The psycho-metric properties of clinical rating scales used in multiple sclerosis . Brain 1999; 122: 141-145 .

Hobart J , Freeman J , Thompson A. Kurtzke scales revisited: the application of psychometric methods to clinical intuition . Brain 2000; 123: 1027-1040 .

Cutter GR , Baier ML , Rudick RA , Cookfair DL , Fischer JS , Petkau J et al. Development of a multiple sclerosis functional composite as a clinical trial outcome measure . Brain 1999; 122: 871-882 .

Hoogervorst ELJ , Kalkers NF , Uitdehaag BMJ , Polman CH. A study validating changes in Multiple Sclerosis Functional Composite . Arch Neurol 2002; 59: 113-116 .

Cohen JA , Cutter GR , Fischer JS , Goodman AD , Heidenreich FR , Jak AJ et al. Use of the multiple sclerosis functional composite as an outcome measure in phase 3 clinical trials . Arch Neurol 2001; 58: 961-967 .

Thompson AJ. Progress in neurorehabilitation in multiple sclerosis . Curr Opin Neurol 2002; 15: 267-270 .

Fischer JS , LaRocca NG , Miller DM , Ritvo PG , Andrews H , Paty D et al. Recent developments in the assessment of quality of life in multiple sclerosis . Mult Scler 1999; 5: 251-259 .

Baggert B , Camplair P , Boudette D. Cognitive dysfunction in multiple sclerosis: natural history, pathophysiology and management . CNS Drugs 2002; 16: 445-455 .

10.

Maor Y , Olmer L , Mozes B. The relation between objective and subjective impairment in cognitive function among multiple sclerosis patients - the role of depression . Mult Scler 2001; 7: 131-135 .

11.

Amato MP , Ponziani G , Amaducci L. Cognitive impairment in multiple sclerosis: a longitudinal study . Clin Neurophysiol EEG 1999; 50 (Suppl 1): 465-468 .

12.

Rao SM , Leo GJ , Ellington L , Nauertz T , Bernardin L , Unverzagt F. Cognitive dysfunction in multiple sclerosis. II. Impact on employment and social functioning . Neurology 1991; 41: 692-696 .

13.

Gold SM , Heesen C , Schulz H , Guder U , Mönch A , Gbadamosi J et al. Disease specific quality of life in multiple sclerosis: validation of the Hamburg Quality of Life Questionnaire in Multiple Sclerosis (HAQUAMS) . Mult Scler 2001; 7: 119-130 .

14.

Hobart J , Lamping D , Fitzpatrick R , Riazi A , Thompson A. The Multiple Sclerosis Impact Scale (MSIS-29). A new patient-based outcome measure . Brain 2001; 124: 962-973 .

15.

Pfennings LE , Van der Ploeg HM , Cohen L , Bramsen I , Polman CH , Lankhorst GJ et al. A health-related quality of life questionnaire for multiple sclerosis patients . Acta Neurol Scand 1999; 100: 148-155 .

16.

Ritvo PG , Fischer JS , Miller, DM , Andrews H , Paty DW , LaRocca NG. Multiple Sclerosis Quality of Life Inventory (MSQLI): a user’s manual. National Multiple Sclerosis Society: New York , 1997.

17.

Cella D , Dineen K , Arnason B , Reder A , Wabster KA , Karabatsos G et al. Validation of the functional assessment of multiple sclerosis quality of life instrument . Neurology 1996; 47: 129-139 .

18.

Vickrey BG , Hays RD , Harooni R , Myers LW , Ellison GW. A health related quality of life measurement for multiple sclerosis . Qual Life Res 1995; 4: 187-206 .

19.

Riemsma RP , Forbes CA , Glanville JM , Eastwood AJ , Kleijnen J. General health status measures for people with cognitive impairment: learning disorders and acquired brain injury . Health Technol Assess 2001; 5: 1-100 . Available online at http://www.hta.nhsweb.nhs.uk/

20.

Poser CM , Paty DW , Scheinberg L. New diagnostic criteria for multiple sclerosis: Guidelines for research protocols . Ann Neurol 1983; 13: 227-231 .

21.

Zigmond AS , Snaith RP. The hospital anxiety and depression scale . Acta Psychiatr Scand 1983; 67: 361-370 .

22.

Mumford C , Compston A. Problems with rating scales for multiple sclerosis: a novel approach-the CAMBS score . J Neurol 1993; 240: 209-215 .

23.

Smith A. The symbol digit modalities test . Learn Dis 1968; 3: 83-91 .

24.

Demaree HA , DeLuca J , Gaudino EA , Diamond BJ. Speed information processing as a key deficit in multiple sclerosis: implications for rehabilitation . J Neurol Neurosurg Psych 1999; 67: 661-663 .

25.

Rudick R , Antel J , Confavreux C , Cutter G , Ellison G , Fischer J et al. Recommendations from the National Multiple Sclerosis Society Clinical Outcomes Assessment Task Force . Ann Neurol 1997; 42: 379-382 .

26.

Feldt LS , Woodruff DJ , Salih FA. Statistical inference for coefficient alpha . Appl Psychol Measure 1987; 11: 93-103 .

27.

Deyo RA , Diehr P , Patrick, DL. Reproducibility and responsiveness of health status measures-statistics and strategies for evaluation . Control Clin Trials 1991; 12: 142-58S .

28.

Van der Putten JMF , Hobart JC , Freeman JA , Thompson, AJ. Measuring change in disability following inpatient rehabilitation: comparison of the responsiveness of the Barthel index and the functional independence measure . J Neurol Neurosurg Psychiatry 1999; 66: 480-484 .

29.

Carey KB , Maisto SA , Carey MP , Purine DM. Measuring readiness-to-change substance misuse among psychiatric out-patients: I. Reliability and validity of self-report measures . J Stud Alcohol 2001; 62: 79-88 .

30.

Khatri P , Babyak M , Clancy C , Davis R , Croughwell N , Newman M et al. Perception of cognitive function in older adults following coronary artery bypass surgery . Health Psychol 1999; 18: 301-306 .

31.

Hoogervorst ELJ , van Winsen LM , Eikelenboom MJ , Kalkers NF , Uitdehaag BM , Polman CH. Comparison of patient self-report, neurological examination, and functional impairment in MS . Neurology 2001; 56: 934-937 .

32.

Carr AJ , Gibson B , Robinson PG.

Measuring quality of life: is quality of life determined by expectations or experience?

BMJ 2001; 322: 1240-1243 .

33.

Liang MH , Lew RA , Stucki G , Fortin PR , Daltroy L. Measuring clinically important changes with patient-oriented questionnaires . Med Care 2002; 40 (Suppl 4): II45-II51 .