Trond Riise

The epidemiology of multiple sclerosis in Europe

Multiple sclerosis (MS) is a chronic and potentially highly disabling disorder with considerable social impact and economic consequences. It is the major cause of non‐traumatic disability in young adults. The social costs associated with MS are high because of its long duration, the early loss of productivity, the need for assistance in activities of daily living and the use of immunomodulatory treatments and multidisciplinary health care. Available MS epidemiological estimates are aimed at providing a measure of the disease burden in Europe. The total estimated prevalence rate of MS for the past three decades is 83 per 100 000 with higher rates in northern countries and a female:male ratio around 2.0. Prevalence rates are higher for women for all countries considered. The highest prevalence rates have been estimated for the age group 35–64 years for both sexes and for all countries. The estimated European mean annual MS incidence rate is 4.3 cases per 100 000. The mean distribution by disease course and by disability is also reported. Despite the wealth of epidemiological data on MS, comparing epidemiological indices among European countries is a hard task and often leads only to approximate estimates. This represents a major methodological concern when evaluating the MS burden in Europe and when implementing specific cost‐of‐illness studies.

Quality of life in multiple sclerosis: Measuring the disease effects more broadly

Objective: To compare the Expanded Disability Status Scale (EDSS) and self-rated quality of life scores (SF-36 Health Survey) as measures of disease impact in a representative sample of MS patients. Background: The EDSS is the most common outcome measure of impairment/disability for MS patients but is heavily weighted toward mobility. Sensitive outcome measures are needed that also capture other aspects of the effects of MS. Methods: The authors performed a cross-sectional study of the cohort of all individuals with onset of MS between 1976 and 1986 who were diagnosed before 1995 in Hordaland County, Norway. A total of 194 patients (94%) participated. Results: The patients had lower mean scores for all eight SF-36 health dimensions compared with sex- and age-adjusted scores in a general population. EDSS scores correlated highly with physical functioning (r = −0.86, R2 = 0.73), and explained some of the variation in social functioning (r = −0.48, R2 = 0.23) and general health (r = −0.46, R2 = 0.21) but little for the other dimensions. Conclusions: The SF-36 captures the broad effects of MS, and the results showed that patients also are bothered frequently with health problems such as bodily pain and low vitality. These problems, which are not reflected in the Expanded Disability Status Scale, should be given more attention in the treatment of MS and when evaluating interventions.

Smoking is a risk factor for multiple sclerosis

The authors determined the relationship between tobacco smoking and the risk of developing multiple sclerosis (MS) in a general population of 22,312 individuals living in Hordaland, Norway in 1997. A total of 87 individuals reported having developed MS. The risk of MS was higher among smokers than among never-smokers (rate ratio 1.81, 95% CI 1.1 to 2.9; p = 0.014). Studies on how smoking interacts with disease onset may contribute to determining the causal agents of this disease.

Prevalence of bladder, bowel and sexual problems among multiple sclerosis patients two to five years after diagnosis:

Most multiple sclerosis (MS) patients experience some sexual, bladder and/or bowel dysfunction during the course of the disease - one of MS most disabling features. This study estimated the frequency of these problems among patients, two to five years after diagnosis, and investigated how these problems are associated with health-related quality of life (using the Multiple Sclerosis Quality of Life-54 questionnaire). The study population comprised a cohort of patients (n=56), diagnosed in a three-year period, in Hordaland County, Norway. The patients were examined clinically, including scoring of the Expanded Disability Status Scale (EDSS), and completed questionnaires related to bowel and bladder dysfunction, sexual problems and health-related quality of life. More than half the patients had bladder and sexual problems. The frequency of self-reported bladder problems corresponded to the relatively high levels of residual urine found. The presence of these problems was associated with lower scores on the quality of life scales. Further, the bowel problems reported were markedly associated with the quality of life scores. Since treatments and preventive strategies can manage many of these problems, we suggest increasing the focus on these aspects of the disease when consulting patients, including at early stages.

Disability and prognosis in multiple sclerosis: demographic and clinical variables important for the ability to walk and awarding of disability pension

Objective: To evaluate disability and prognosis in an untreated population-based incidence cohort of multiple sclerosis (MS) patients. Methods: The Expanded Disability Status Scale (EDSS) score was recorded in 220 MS patients. Disease progression was assessed by life table analysis with different endpoints and multivariate Cox regression analysis was performed for evaluation of prognostic factors. Results: The probability of being alive after 15 years was 94.8+1.8% (s.e.), of managing without a wheelchair (EDSS57.0) 75.8+3.2%, of walking without walking assistance (EDSS56.0) 60.3+3.6%, and of not being awarded a disability pension 46.0+3.7%. The probability of still having a relapsing-remitting (RR) course after 15 years was 62.0+4.1%. A RR course and long interval between the initial (onset) and second episode (43 years) predicted favorable outcome. There was also a trend towards favorable outcome in patients with optic neuritis, sensory symptoms and low age at onset, but these factors were associated with the RR course. Motor symptoms and high age at onset indicated unfavorable outcome, but these factors were associated with the primary progressive course. Conclusions: A RR course and long inter-episode intervals in the early phase of the disease were associated with a better outcome. Other onset characteristics indicating a favorable outcome were associated with the RR course while characteristics indicating an unfavorable outcome were associated with the PP course.

Performance of the SF-36, SF-12, and RAND-36 summary scales in a multiple sclerosis population.

Background.Multiple sclerosis (MS) patients accumulate both physical and mental health problems along with disease progression. Valid and sensitive outcome measures are important to measure disease effects and the effect of treatment. Objective.The objective of this study was to test the performance of the physical and mental summary scales of SF-36, SF-12, and RAND-36. Methods.The scales were evaluated by comparing the scores of a cohort of 194 MS patients with general population data and using the Expanded Disability Status Scale (EDSS) and the Incapacity Status Scale–mental as criterion variables for physical functioning and mental health. Results.All 3 physical summary scales were markedly reduced and correlated highly with the EDSS. The SF-36 mental summary score was only slightly reduced among MS patients (0.2 SD) compared with the general population, despite significantly reduced scores on all 4 health scales being most related to mental health and despite a high prevalence of mental health problems. This results from the poor physical functioning (mean scale score, 2.3 SD below the general population) and the orthogonal factor rotation used to derive independent measures of physical and mental health. Similar results were found for the SF-12. The nonorthogonal RAND-36 physical and mental summary scores were both markedly reduced. This is more compatible with the disease progression in MS and the results of the other measures of physical and mental health used in the study. Conclusions.The SF-36 and SF-12 mental health summary scales appear to overestimate mental health in people with MS.

Low back pain and widespread pain predict sickness absence among industrial workers

BackgroundThe prevalence of musculoskeletal disorders (MSD) in the aluminium industry is high, and there is a considerable work-related fraction. More knowledge about the predictors of sickness absence from MSD in this industry will be valuable in determining strategies for prevention. The aim of this study was to analyse the relative impact of body parts, psychosocial and individual factors as predictors for short- and long-term sickness absence from MSD among industrial workers.MethodsA follow-up study was conducted among all the workers at eight aluminium plants in Norway. A questionnaire was completed by 5654 workers at baseline in 1998. A total of 3320 of these participated in the follow-up study in 2000. Cox regression analysis was applied to investigate the relative impact of MSD in various parts of the body and of psychosocial and individual factors reported in 1998 on short-term and long-term sickness absence from MSD reported in 2000.ResultsMSD accounted for 45% of all working days lost the year prior to follow-up in 2000. Blue-collar workers had significantly higher risk than white-collar workers for both short- and long-term sickness absence from MSD (long-term sickness absence: RR = 3.04, 95% CI 2.08–4.45). Widespread and low back pain in 1998 significantly predicted both short- and long-term sickness absence in 2000. In addition, shoulder pain predicted long-term sickness absence. Low social support predicted short-term sickness absence (RR = 1.28, 95% CI 1.11–1.49).ConclusionsReducing sickness absence from MSD among industrial workers requires focusing on the working conditions of blue-collar workers and risk factors for low back pain and widespread pain. Increasing social support in the work environment may have effects in reducing short-term sickness absence from MSD.

Quality of life as a predictor for change in disability in MS.

Objective: To investigate the predictive value of quality of life on changes in disability measured by the Expanded Disability Status Scale (EDSS). Background: There are few good prognostic factors for disease development in MS. Quality of life and self-rated health have been shown to be highly predictive of morbidity and disease development in heart disease and cancer. Methods: Data on quality of life (SF-36 Health Survey) were ascertained at baseline for 97 relapsing-remitting patients with MS participating in a short-term clinical trial on interferon α-2a. These scores were correlated with change in EDSS scores 1 year later, 6 months after treatment ended. Results: Low scores on the SF-36 mental health scale were correlated with increased (worsened) EDSS scores 1 year later (r = −0.29, p = 0.006). The results were not altered by adjusting for disease activity at baseline, which was measured by the number gadolinium-enhanced MRI lesions, relapse rate for the preceding 2 years, and baseline EDSS score. Similar results were found for self-rated health (according to the first question of the SF-36). Conclusions: These findings reinforce the importance of incorporating the patients’ evaluation of their quality of life during treatment. Further, assessing such measures is important in evaluating effects in treatment trials in MS.

History of Foot Ulcer Increases Mortality Among Individuals With Diabetes Ten-year follow-up of the Nord-Trøndelag Health Study, Norway

OBJECTIVE To compare mortality rates for individuals with diabetes with and without a history of foot ulcer (HFU) and with that for the nondiabetic population. RESEARCH DESIGN AND METHODS This population-based study included 155 diabetic individuals with an HFU, 1,339 diabetic individuals without an HFU, and 63,632 nondiabetic individuals who were all followed for 10 years with mortality as the end point. RESULTS During the follow-up period, a total of 49.0% of diabetic individuals with an HFU died, compared with 35.2% of diabetic individuals without an HFU and 10.5% of those without diabetes. In Cox regression analyses adjusted for age, sex, education, current smoking, and waist circumference, having an HFU was associated with more than a twofold (2.29 [95% CI 1.82–2.88]) hazard risk for mortality compared with that of the nondiabetic group. In corresponding analyses comparing diabetic individuals with and without an HFU, an HFU was associated with 47% increased mortality (1.47 [1.14–1.89]). Significant covariates were older age, male sex, and current smoking. After inclusion of A1C, insulin use, microalbuminuria, cardiovascular disease, and depression scores in the model, each was significantly related to life expectancy. CONCLUSIONS AN HFU increased mortality risk among community-dwelling adults and elderly individuals with diabetes. The excess risk persisted after adjustment for comorbidity and depression scores, indicating that close clinical monitoring might be warranted among individuals with an HFU, who may be particularly vulnerable to adverse outcomes.

The use of quality of life measures in multiple sclerosis research.

Q uality of life research contributes knowledge essential to the health and healthcare of multiple sclerosis (MS) patients. This article reviews 83 MS studies in English that have presented data on quality of life. The studies may be classified into three categories, according to the application and the main focus: 1) evaluating the development and validity of quality of life questionnaires and clinical scales (n-27); 2) evaluating factors that might influence the quality of life or comparing the quality of life among various groups (n-37); and 3) using quality of life questionnaires as outcome measures in medical trials and other interventions (n-19). The studies have shown that quality of life questionnaires more broadly measure the impact of MS than do the most frequently used measures of disease activity and effects. Using quality of life measures provides additional information in evaluating the effects of treatment and in studying the development of the disease. Such information is crucial in planning interventions for MS patients. A challenge in this field is to improve the study designs, including reaching some agreement on how to measure the quality of life.