Lilian Pfennings

Exploring differences between subgroups of multiple sclerosis patients in health-related quality of life

Abstract Health-related quality of life (HRQoL) questionnaires finding increasing use in medicine, but still only few publications have reported on HRQoL in patients with multiple sclerosis (MS). Because of its progressive and disabling nature, the disease has a considerable effect on HRQoL. To facilitate the interpretation of scores for the heterogeneous MS population, we explored differences between subgroups of MS outpatients (n = 90) on two HRQoL instruments: the Medical Outcome Study Short Form-36 and the Disability and Impact Profile. Three disease-related characteristics were studied: severity of MS, time since diagnosis, and MS progression in the past 6 months. The results show that each of these have an effect on one or more aspects of HRQoL. Thus, the longer the disease duration and the more severe and progressive the MS, the lower is the patient’s experienced HRQoL.

Value of health-related quality of life to predict disability course in multiple sclerosis

Objective: To determine the value of health-related quality of life (HRQoL) to predict change in disability status in patients with multiple sclerosis (MS). Methods: Over a 5-year period, data were collected on HRQoL (Medical Outcomes Study Short Form-36 Health Survey) and disability status (Expanded Disability Status Scale) from a heterogeneous group of 81 Dutch-speaking patients with MS. Results: Multivariate logistic regression analysis showed that HRQoL in the domains of Physical Functioning and Role-Physical Functioning is a significant predictor of change in disability status. Conclusions: A patient’s subjectively perceived health-related quality of life may not be only a clinically and psychosocially meaningful outcome per se but may also be a predictor of objective outcomes such as change in disability status over a substantial period of time.

A health-related quality of life questionnaire for multiple sclerosis patients

Objective ‐ The construction of a brief, valid and reliable HRQoL questionnaire for use in multiple sclerosis patients based on generic and disease‐specific HRQoL measures. Material and methods ‐ The Medical Outcomes Study 36‐item Short Form Health Survey (SF‐36), COOP/WONCA Charts, and Disability & Impact Profile (DIP) were used in a longitudinal study in 162 patients with multiple sclerosis. Results ‐ Factor analyses identified 2 underlying dimensions of HRQoL, relating to “physical functioning” and “psychological functioning”. Selection of the 3 highest loading reliable scales on each factor resulted in a final questionnaire consisting of 3 scales of the SF‐36 and 3 scales of the DIP. In total 40 items were selected; completion time is about 10 min. Conclusion ‐ The final questionnaire adequately measured 2 dimensions of HRQoL. The length of the questionnaire is acceptable for patients with MS in view of respondent burden.

Preconditions for Sensitivity in Measuring Change: Visual Analogue Scales Compared to Rating Scales in a Likert Format:

In a study of preconditions of responsiveness, we examined the variances obtained by two different ways of responding to questionnaire items. Subjects were 168 first-year medical students. They all completed a questionnaire of nine items. The original Liken-like scoring was (partially) replaced by visual analogue scoring in three quarters of the questionnaires. For three items the analogue form had a significantly greater variance than the discrete form, but no discrete item had a significantly greater variance than its analogue counterpart. Assuming that a greater variance was indicative for a greater responsiveness, our findings provide some support for the preferred use of analogue scales over discrete response categories in the measurement of changes over time.

A comparison of responsiveness indices in multiple sclerosis patients

Responsiveness was measured in a number of health-related quality of life (HRQoL) instruments among which two generic (SF-36 and COOP/WONCA Charts) and one disease-specific instrument, the Disability & Impact Profile (DIP). Subjects were 162 multiple sclerosis patients. The following responsiveness indices were used: effect size, standardised response mean and smallest real difference (SRD). The latter measure gives an indication of the magnitude of real change, i.e. change not attributable to ‘noise’ or ‘error’ and can thus be used for the interpretation of change scores in clinical practice whereby change scores larger than the SRD value indicate real change. It is assumed that low SRD values indicate high responsiveness. The results confirmed our expectation that the effect size and standardised response mean are probably less suitable for use in slowly progressive diseases, since they use the average change as the numerator. Therefore, the article focused on the SRD. Compared to scales, items measured on a visual analogue scale show high SRD values. The DIP scales generally show lower SRD values compared to scales of other questionnaires. The SRD seems to be a promising new measure to study responsiveness. More research into the interpretation of this measure is necessary.

USING THE SHORT FORM-36 WITH MULTIPLE SCLEROSIS PATIENTS IN FIVE COUNTRIES: A CROSS-CULTURAL COMPARISON

Questionnaires measuring health-related quality of life are increasingly used in international studies of medical effectiveness. It is important to know if data from these instruments are comparable across countries. We initiated a collaboration among five research groups—from the USA, The Netherlands, Belgium, France, and the UK—in the field of health-related quality of life in multiple sclerosis. All groups used the 36-item Short Form Health Survey. The goal of our study was to make a cross-cultural comparison. In the five countries under study the sample size varied from 50 to 134 patients with multiple sclerosis. The survey was completed by a total of 457 patients, who were heterogeneous in relation to age, duration of illness, severity and type of multiple sclerosis. There appeared to be major differences among the samples in scores on each of the eight scales. These findings may be influenced by differences in method of recruitment, demographic and disease-related characteristics, administration, and cultural factors. After having performed a number of analyses, it appeared that the differences were mainly attributable to sampling effects; however, cultural influences could not be excluded.

Factor structure of the disability and impact profile in patients with multiple sclerosis

The Disability and Impact Profile (DIP) is used for the measurement of quality of life in multiple sclerosis (MS) patients. Data from 211 persons with definite MS from Belgium, Denmark and the Netherlands were used to address three questions. To what extent do the impairment ratings and their complementary weighted scores share common variance? What is the factor structure of the weighted scores? To what extent do disease-related information and information from psychological questionnaires offer concurrent validity for the factors? Correlations between impairment ratings and the weighted item scores were high; for most items the complementary ratings of impact do not supplement information provided by impairment ratings. The DIP weighted scores can be represented to some extent by three independent dimensions: a motor (skeletal movement) or displacement ability factor, a factor relating to sensory–cognitive intactness and a psychological well-being factor. A two-factor solution provides a first factor identical to that of the three-factor solution and a second factor representing psychological well-being. The two factors correlate well with instruments measuring disability and with satisfaction versus emotional distress. Provisional scales based on the factors were constructed.

Development of a Cognitive Behavioral Group Intervention Programme for Patients with Multiple Sclerosis: An Exploratory Study

A substantial group of patients with multiple sclerosis (MS) has difficulty coping with their disease. Cognitive behavioral group interventions may help these patients cope more effectively with MS. We developed an 8-session group intervention programme for patients recently diagnosed with MS to help them cope more effectively with MS and to overcome negative thoughts and beliefs about the disease to improve health-related quality of life. We tested the feasibility of the group intervention programme and health-related quality of life in a sample of 11 patients recently diagnosed with MS [mean age: 38 (±7.9) yr.; 8 women and 3 men]. All patients were recruited through direct referral by their neurologist or by an MS nurse specialist. The programme was conducted in two small groups of 7 patients each, and each group was led by two psychologists. Cognitive behavioral therapy was an important ingredient in each group session as well as sharing of personal experiences and discussing homework assignments. Each session was formatted the same way but addressed a different MS-specific theme, for example, ‘coping with physical impairments’ or ‘communication with medical staff’. Participants experienced a significant improvement in the health-related quality of life domains of psychological status and vitality, as measured by subscales of Disability and Impact Profile and the Short Form-36 Health Survey. Although further studies are warranted, it appears that a short group intervention programme based on cognitive behavioral techniques for patients with MS might have a positive influence on health-related quality of life.

Reliability of Two Measures of Health-Related Quality of Life in Patients with Multiple Sclerosis

Multiple sclerosis is a chronic neurological disease which can cause a variety of symptoms (motor and sensory impairment, visual problems, bladder and bowel problems, sexual dysfunction, and decline in cognitive function). Both the Medical Outcome Study Short Form-36, a generic questionnaire regarding health-related quality of life, and the Disability and Impact Profile, a similar questionnaire developed for people with chronic diseases, are used regularly to assess patients with multiple sclerosis. Over a 6-mo. interval 187 patients with multiple sclerosis completed these questionnaires twice. Internal consistency of both questionnaires at Times 1 and 2 was .60 or above for all eight scales of the Medical Outcome Study Short Form—36 and five scales of the Disability and Impact Profile. Estimates of test-retest reliability for three scales of the Medical Outcome Study Short Form—36 were below .60, but for all scales of the Disability and Impact Profile were .60 or higher. The two questionnaires appeared to be reliable for our sample of patients with multiple sclerosis.