Patients' assessment of quality of life instruments: a randomised study of SIP, SF-36 and SEIQoL-DW in patients with amyotrophic lateral sclerosis

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Abstract

The evaluation of quality of life (QoL) plays an increasingly important role in clinical research and drug trials in ALS. However, most of the scales employed so far are based on a fixed external value system, and may therefore not reflect the patients' subjective perception of QoL accurately. In addition, many ALS patients complain about the psychological distress inflicted by QoL questionnaires which focus on functional status, as they constantly remind patients of their deterioration. We therefore asked 42 ALS patients to assess, using visual analogue scales, their subjective perception of the validity of three QoL instruments as well as the emotional distress caused by them. The scales were: the Sickness Impact Profile (SIP), the Short Form 36 (SF-36), and the Schedule for the Evaluation of Individual QoL-Direct Weighting (SEIQoL-DW). Patients were examined at least three times at two-month intervals. The SIP was filled out by all patients, the SF-36 and the SEIQoL-DW were assigned at random. The validity of the SEIQoL-DW was rated higher than that of the SIP (p<0.001) and of the SF-36 (p<0.001). The SIP imparted a higher emotional distress to patients than the SEIQoL-DW (p<0.005), with a trend in the same direction for the SF-36 (p=0.082). The most frequently mentioned QoL-relevant domains in the SEIQoL-DW were family (100%), health (53%), and profession (50%). These results should prompt further discussion and investigation on the most appropriate way to assess QoL in patients with ALS.

Introduction

Quality of Life (QoL) is now regarded as a fundamental goal of medical care [15]. In amyotrophic lateral sclerosis (ALS), a neurodegenerative disease of the motor system leading to progressive weakness of voluntary muscles and death within 3 years [36], the evaluation of this parameter plays an increasingly important role in clinical research, drug trials [9], [24], and palliative care [7]. However, most of the QoL scales employed so far are heavily weighted toward functional status [32], thus confronting ALS patients with their progressive loss of function. Traditional, so-called “health-related” QoL questionnaires are also frequently based on a fixed, external, health-based value system [16] and may therefore not reflect the patients' individual QoL accurately [12], [17]. In our clinical experience such questionnaire-based scales may actually impart considerable distress to patients with ALS. Two typical representatives of these health-related QoL instruments are the Sickness Impact Profile (SIP) [4] and the Short Form-36 (SF-36) [40]. The SIP has been frequently used in ALS drug trials [3], [5], [6], [21], while the SF-36 was the main outcome measure in a recent European collaborative study on QoL of ALS patients and carers [19].

In the last decade a new approach to QoL assessment was developed which focuses on the individual aspect of QoL, the Schedule for the Evaluation of Individual QoL - Direct Weighting (SEIQoL-DW) [18]. This instrument, which has been validated in a number of patient populations and healthy subjects [11], [18], [34], [39], allows the patients to name and rate, from their own perspective, the areas of life which are most important to their overall QoL.

In order to identify patients' preferences concerning these different approaches to QoL measurement, we performed a randomised trial of SIP, SF-36 and SEIQoL-DW in patients with ALS, asking the patients themselves to evaluate the scales in terms of subjectively perceived validity and distress.

Section snippets

Patients and methods

Patients with a probable or definite diagnosis of ALS according to the El Escorial criteria [10] referred consecutively to the Motor Neuron Outpatient Clinic of the Department of Neurology, Ludwig-Maximilians-University, Munich, Germany between April 1998 and May 1999 were asked to participate in the study. All participants had to meet the following criteria: fluency in German or English, absence of dementia, ability and willingness to come to our clinic every 2 months, absence of serious

Demographic data

Out of 62 eligible patients, 51 (82%) agreed to take part in the study and gave their informed consent. Nine patients (18%) did not complete the study due to death, withdrawal of consent and progression of disease. Study completion (at least three assessments at two-monthly intervals) was achieved by 42 patients (21 each in the SIP/SEIQoL-DW and the SIP/SF-36 subgroups). In 24 cases it was possible to perform five or more assessments (analysis of longitudinal data is forthcoming). The

Discussion

In this study, patients with ALS were asked to complete QoL assessments with the SIP and either the SF-36 or the SEIQoL-DW, and to then rate each of the instruments in terms of subjectively perceived validity and emotional distress inflicted by the completion of the scale. The data show that the SEIQoL-DW is considered to be significantly more valid than either SIP or SF-36. The SIP was found to impart significantly more emotional distress to patients than the SEIQoL-DW and (in one visit) the

Acknowledgements

We thank S. Clarke for helpful comments and Dr. P. Kolyschkow for assistance with the statistical analyses. Our warmest thanks go to our patients for their willingness to participate in the study.

References (41)

  • M. Bretscher et al.

    Quality of life in hospice patients. A pilot study

    Psychosomatics

    (1999)
  • S.B. Detmar et al.

    Quality of life assessment in daily clinical oncology practice: a feasibility study

    Eur. J. Cancer

    (1998)
  • M. Kagawa-Singer

    Redefining health: living with cancer

    Soc. Sci. Med.

    (1993)
  • R.T. Anderson et al.

    Critical review of the international assessments of health-related quality of life

    Qual. Life Res.

    (1993)
  • M. Angell

    The quality of mercy

    N. Engl. J. Med.

    (1982)
  • Anonymous

    A controlled trial of recombinant methionyl human BDNF in ALS: The BDNF Study Group (Phase III)

    Neurology

    (1999)
  • M. Bergner et al.

    The sickness impact profile: development and final revision of a health state measurement

    Med. Care

    (1981)
  • G.D. Borasio

    Amyotophic lateral sclerosis: lessons in trial design from recent trials

    J. Neurol. Sci.

    (1998)
  • G.D. Borasio et al.

    A placebo-controlled trial of insulin-like growth factor-I in amyotrophic lateral sclerosis. European ALS/IGF-I Study Group

    Neurology

    (1998)
  • G.D. Borasio et al.

    Palliative care in amyotrophic lateral sclerosis

    J. Neurol.

    (1997)
  • B.R. Brooks

    Clinical evaluation of ALS drugs

    Neurology

    (1997)
  • B.R. Brooks

    El Escorial World Federation of Neurology criteria for the diagnosis of amyotrophic lateral sclerosis. Subcommittee on Motor Neuron Diseases/Amyotrophic Lateral Sclerosis of the World Federation of Neurology Research Group on Neuromuscular Diseases and the El Escorial “Clinical limits of amyotrophic lateral sclerosis” workshop contributors

    J. Neurol. Sci.

    (1994)
  • J.P. Brown et al.

    Development of a direct weighting procedure for quality of life domains

    Qual. Life Res.

    (1997)
  • S.R. Cohen et al.

    Existential well-being is an important determinant of quality of life

    Cancer

    (1996)
  • A.M. Damiano et al.

    Measurement of health-related quality of life in patients with amyotrophic lateral sclerosis in clinical trials of new therapies

    Med. Care

    (1999)
  • R.W. Ewans

    Quality of life

    Lancet

    (1991)
  • T.M. Gill et al.

    A critical appraisal of the quality of quality of life measurements

    JAMA

    (1994)
  • A.G. Guyatt et al.

    Health status, quality of life, and the individual

    JAMA

    (1994)
  • M.A. Hickey et al.

    A new short form individual quality of life measure (SEIQoL-DW): application in a cohort of individuals with HIV/AIDS

    BMJ

    (1996)
  • C. Jenkinson et al.

    The ALS Health Profile Study: quality of life of amyotrophic lateral sclerosis patients and carers in Europe

    J. Neurol.

    (2000)
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    Present address: Department of Neurology, Ernst-Moritz-Arndt-University, Greifswald, Germany.

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