DÄ internationalArchive7/2008Multiple Sclerosis Registry in Germany – Results of the Extension Phase 2005/2006

Review article

Multiple Sclerosis Registry in Germany – Results of the Extension Phase 2005/2006

Dtsch Arztebl Int 2008; 105(7): 113-9. DOI: 10.3238/arztebl.2008.0113

Flachenecker, P; Stuke, K; Elias, W; Freidel, M; Haas, J; Pitschnau-Michel, D; Schimrigk, S; Zettl, U K; Rieckmann, P

Introduction: In 2001, a nationwide multiple sclerosis (MS) registry was initiated in Germany under the auspices of the German MS Society, (DMSG Bundesverband e.V.). The project aimed at collecting epidemiological data and information on health care provision for MS patients in Germany.
Methods: After a 2-year pilot phase, the original entry mask was modified, and new centers were recruited, resulting in the registration of a total of 5821 patients in 2005 and 2006. Following a 2 stage quality control process, standardized data sets for 5445 patients (93.5%) were able to be analyzed.
Results: Mean duration from onset of disease to diagnosis was 3.5 years. More than 70% of patients received immunomodulatory drugs, whereas symptomatic treatments were less commonly administered. The number of participating centers as of 31 December 2006 was 57 (29 neurological hospitals, 11 rehabilitation units, 13 specialized practitioners, and 4 regional MS centers).
Discussion: The MS registry provides valuable data on patterns of care for MS patients in Germany, and may help to improve service provision and overall quality of life for these patients.
Dtsch Arztebl Int 2008; 105(7): 113–9
DOI: 10.3238/arztebl.2008.0113
Key words: multiple sclerosis, MS registry, epidemiology, database mangagement system, drug therapy, ability to work
LNSLNS Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) and is the most common disease to cause chronic disability in young adults. It has been estimated that some 120 000 to 140 000 patients are affected by MS in Germany, although the exact number is unknown. The distribution of the disease according to its different subtypes or severity is also unclear (1).

Despite the high economic burden of MS on society, with total annual costs of 40 000 euros per patient (2), there are still limited data on patterns of care for patients with this disease. A comprehensive multiple sclerosis registry is therefore highly desirable, both from a health economic perspective and to ensure the targeted use of limited resources. To date, there has been no systematic attempt to collect the necessary data in Germany. To address this deficit, a nationwide registry was initiated in 2001 under the auspices of the German MS Society (Deutsche Multiple Sklerose Gesellschaft Bundesverband e.V.) with the aim of providing cross-sectional data on the frequency of MS and its subtypes in Germany. Another objective was to obtain information on the distribution of disease severity, the effect of MS on patients' ability to work, and the use of immunomodulatory, symptomatic, and non-pharmacological treatments. Following the 2-year pilot phase, in which 3223 patients took part (3), we present here the results of the extension phase of the study.

Methods
During the pilot phase, all MS patients were included who were treated at participating centers between 7 January 2002 and 31 December 2003, and who provided written, informed consent that their data be evaluated centrally. Data were collected, stored, and evaluated according to the latest state legislation governing data protection. All five centers that participated in the pilot phase were specialized in the management of MS patients and were representative of different regions and hospital types throughout Germany (3).

Based on experience gained during the pilot phase, the input mask (3) was modified. Parameters were deleted if they were regarded as unnecessary, amended if incomplete, and reworded if they were unclear and could be easily misunderstood. This streamlined the data sets, ensuring that they would be sufficiently precise and clear. The full questionnaire is available from the authors upon request. Documentation was performed on-site in the study centers by participating physicians.

Data sets were coded using pseudonyms and sent every three months on a digital storage medium to the non-profit organization MS Research and Project Development (MS-Forschungs- und Projektentwicklungs-gGmbH) in Hannover, Germany for quality control and evaluation. There, data sets were checked for completeness (age, gender, degree of disability, and reliability of diagnosis) and consistency, and those with missing data or inconsistencies were returned for completion or correction. Using a unique key, we were able to identify redundant data sets, which had been entered either multiple times at one center (longitudinal analysis) or consecutively at more than one center (e.g. acute inpatient treatment and subsequent rehabilitation therapy). For the cross-sectional analysis, only the most recent data set was used.

Results
In the 2-year pilot phase, 3458 standardized data sets were collected. Of these, 3223 (93.2%) passed quality control and were eligible for further analysis (3). Since 15 March 2005, the number of new centers participating in the registry has grown continuously, totaling 57 by the 31 December 2006 report date (figure 1 gif ppt). So far, a total of 5821 data sets have been collected from 35 centers (figure 2 gif ppt). Of these data sets, 5445 (93.5%) passed quality control and were eligible for further analysis. Data from the remaining centers were not delivered until after the report date and were thus not included in the evaluation. Because some of the data sets were not complete for all parameters, different bases for comparison were used for the individual evaluations.

Demographic data and clinical characteristics
At the time of data collection, patients' mean age (± standard deviation) was 44.2 ± 11.5 years, and disease duration was 12.7 ± 9.2 years. Age at onset of disease was 31.4 ± 10.2 years (7 to 75 years). Onset occurred between the ages of 20 and 40 (70%) in the large majority of patients, but in 9 patients it occurred before age 10 (0.2%) and in 44 patients after age 60 (0.9 %). A total of 4.9% patients manifested the disease after the age of 50.

At the time of diagnosis, patients were 34.8 ± 10.7 years old, which means that the mean duration between onset of disease and diagnosis was 3.4 ± 5.5 years. This duration remained virtually unchanged in patients newly diagnosed after 1999 (3.6 years). Women were 2.5 times more likely than men to contract MS (72% vs. 28%). In total, 55% of patients had relapsing-remitting MS, 32% secondary progressive MS, and 9% primary progressive MS (i.e. from the outset). In total, 1% of patients presented with their first MS event. In 16.9% of patients, the clinical condition was stable within the last year, whereas 17.1% of patients experienced more than one relapse or rapid progression. The majority of patients (56.0%) exhibited slow progression or less than one relapse per year.

Degree of disability
The Kurtzke Expanded Disability Status Scale (EDSS) is the international standard for quantifying a patient's degree of disability (4). The distribution of EDSS scores in our population can be seen in figure 3 (gif ppt). The median EDSS score was 3.5. In total, 51% of patients were fully ambulatory (EDSS <4), 28% of patients required assistance (cane, crutch, brace) to walk 100 m (EDSS ≥6), and 6% were confined permanently to a wheelchair (EDSS ≥8). The likelihood of reaching an EDSS score of 4.0 or 6.0 in relation to age is shown in figure 4 (gif ppt). As can be seen in the figure, 60% of patients aged 50 years, and 40% of patients aged 60 years, did not require assistance to walk 100 m.

Occupational status
Only 1183 patients were still working full-time (27.9%), 1671 patients (39.4%) were in early retirement, 6.0% were unemployed, and just 0.7% were taking part in occupational retraining programs due to MS symptoms. The percentage of patients in early retirement was strongly associated with age (table 1 gif ppt). The relationship between early retirement status and degree of physical disability can be seen in figure 5 (gif ppt). Here it is interesting to note that a substantial number of patients in early retirement (14.8%) had an EDSS score <3.5 and were thus still fully ambulatory.

Immunomodulatory and symptomatic treatment
In total, 71% of patients received immunomodulatory treatment, primarily with interferons (table 2 gif ppt). Treatment escalation with mitoxantrone was also a comparatively frequent strategy. Other treatment options, including intravenous immunoglobulins, were used only infrequently. Altogether 670 patients (20%) did not receive immunoprophylactic treatment, especially those with secondary progressive MS and slow disease progression. However, 98 (14.9%) of the patients who did not receive immunoprophylactic treatment experienced rapid disease progression or frequent relapses. Table 3 (gif ppt) summarizes the different treatment options for the common MS symptoms. In particular, fatigue and cognitive disorders, although quite common, were left untreated in the large majority of patients. In contrast, pain and depression were managed comparatively frequently with pharmacological treatment. Finally, a considerable percentage of patients with spasticity or bladder disorders received neither pharmacological nor non-pharmacological treatment.

Discussion
After the successful completion of the 2-year pilot phase, data collection efforts were expanded as part of the extension phase of the project. In just under 2 years, a total of 5445 data sets were registered.

Course of MS and prognosis
MS is characterized by unpredictable relapses of symptoms (relapsing-remitting MS), with which 90% to 95% of cases begin. In 5% to 10% of cases, patients experience a progressive worsening of disease (primary progressive MS), especially with respect to ambulation. After approximately 10 to 15 years, 30% to 40% of patients with initial relapsing-remitting MS enter the chronic phase (secondary progressive MS) (5) The results of the present survey show a higher percentage of patients with progressive disease compared to the pilot phase (3), as well as a shift towards a greater degree of disability. These findings are likely due to the increased recruitment of rehabilitation centers, as well as of neurologists in practices. The results presented here correspond to those reported in population-based epidemiological studies (611) and indicate that the data are becoming increasingly representative as the registry expands.

Whereas earlier studies investigating the natural course of MS found that 50% of patients required a cane, crutch, or brace to walk 100 m (EDSS 6.0) after a disease duration of approximately 15 years (5, 9), more recent studies suggest a considerably more favorable prognosis, with a median duration of 20 or 29 years until an EDSS of 6.0 is reached (8, 1113). Because the exact time of disease onset is often difficult to establish, it is often more helpful when counseling individual patients to approach the matter by considering the relationship between degree of disability and age.

In our study, 60% of patients aged 50 years and 40% of patients aged 60 years could still walk 100 m without assistance. These results are comparable to those reported in British Columbia, Canada (11).

Most of the patients in our MS registry had already received immunomodulatory treatment for many years, which means that these favorable figures do not reflect the natural course of MS, but rather the course of disease under current care with disease-modulating drugs and improved symptomatic treatment.

Duration from onset of disease to diagnosis
Despite improved testing methods and new diagnostic criteria that generally allow a diagnosis to be made within a month after disease onset (14), the mean duration from onset of disease to diagnosis was comparatively long in the pilot and extension phases of our study, amounting to 3.4 and 3.5 years, respectively. This also applies to patients diagnosed after 1999.

It remains to be seen whether increased awareness about the course of disease and possibilities for early treatment, as well as the more widespread implementation of newer diagnostic criteria, will lead to earlier diagnosis, thus reducing prolonged diagnostic uncertainty. Indeed, just such a trend for other countries has been observed in data from the NARCOMS Registry, established by the Consortium of Multiple Sclerosis Centers in North America (15). Here it is, above all, the responsibility of general practitioners, ophthalmologists, orthopedists, and urologists to ensure that neurological testing is performed in young patients who present with a loss of neurological function that cannot be attributed clearly to peripheral causes. Doing so can help ensure that the appropriate treatment is initiated early in cases of subclinical disease (16, 17).

Ability to work
After a disease duration of just under 13 years, almost 40% of patients (mean age: 44 years) in the registry were receiving pension benefits due to work-related disability. Only 28% of patients were still working full-time. Similar figures have been reported in other studies (2, 7, 18). As was to be expected in light of the higher percentage of MS patients with more severe disease in the extension phase, the results here are less favorable than those seen in the pilot phase (3).

Compared to unemployment rates of 10% to 12% in the general population, the percentage of unemployed MS patients in the extension phase was relatively low. This may reflect the fact that MS patients with more severe disease and disability are more likely to be eligible for early retirement and are thus not counted in unemployment statistics. Moreover, although the percentage of patients in early retirement increased with degree of physical disability (6, 19, 20), a full 15% of the patients in early retirement were still fully ambulatory.

This means that factors other than physical disability must be playing a role in patients' early retirement. Here it should be noted that the EDSS does not provide an adequate picture of cognitive impairments or fatigue, and it is precisely these two factors that are likely to contribute to impaired working capacity (19). It is, therefore, crucial that the symptoms responsible for changes in work status be identified and treatment strategies developed to help patients maintain their ability to work and quality of life (20).

Immunoprophylactic and symptomatic treatment
More than 70% of patients in our registry received disease-modifying treatment, which corresponds to the percentages seen in the pilot phase and in the NARCOMS Registry (21). Almost 50% of patients were given first-line immunomodulatory treatment with interferon beta and glatiramer acetate according to the treatment ladder developed by the German Multiple Sclerosis Treatment Consensus Group (Multiple Sklerose Therapie Konsensusgruppe; MSTKG) (17, 22, 23). In the extension phase, the percentage of patients on mitoxantrone or steroid pulse therapy was higher than in the pilot phase of the study. This is due to the larger number of patients in the extension phase who had progressive MS and for whom these types of treatment are the only available options. Natalizumab was not approved until mid-2006, and there are currently few documented cases of treatment with this agent. Other immunomodulatory treatments, including intravenous immunoglobulins, were used only rarely.

The type and frequency of treatments thus indicate that the evidence-based recommendations developed by the MSTKG, which have been adopted by the Germany Neurological Society in its own treatment guidelines (16), are indeed being implemented in everyday clinical practice. Nevertheless, there are still many patients who do not receive immunoprophylactic treatment despite the presence of active disease (i.e. rapid progression and/or more than one relapse per year). Even more striking is the suboptimal use of symptomatic treatment in most patients, especially in those with cognitive impairments, fatigue, or ataxia. These findings clearly indicate that the care provided to MS patients in Germany is inadequate, both generally and with respect to symptom management (17, 2225).

There are many possible reasons for these observations. For example, it may be that some patients who presented at the centers were seeking advice on appropriate treatments and underwent a change of regimens only after documentation had already taken place. Follow-up studies could shed more light on this issue.

Another possible explanation is that MS patients in Germany are more likely than patients in other European countries to decline or prematurely interrupt treatment, even in cases where treatment is clearly indicated. To address this possibility, physicians must ensure that all patients are provided with comprehensive counseling on the benefits and risks of therapy, and that realistic treatment goals are set (17).

Finally, with regard to MS symptoms such as cognitive impairments or fatigue, either there are no clearly effective treatments or the existing healthcare infrastructure is unable to provide services such as outpatient neuropsychological therapy. There is an urgent need not only for further clinical research on this point, but also for structural changes which will ensure that all MS patients receive proper care.

Limitations of the study
The survey included all patients who visited a participating center during the data collection period, and not only new cases of MS. This is a suitable approach when studying chronic diseases like multiple sclerosis, which are characterized by high prevalence and relatively low incidence (1), precisely because of the diagnostic uncertainty and great psychological burden on patients at the onset of disease.

The survey was not population-based, relying instead on data provided by study centers, which may have led to selection bias. Though desirable, a comprehensive population-based study would require the participation of all individuals and organizations involved in providing care to MS patients, something that is only possible if participation is mandated by law, as is the case in Denmark, for example. Nevertheless, the fact that the demographic data in the present study are comparable to those reported in population-based epidemiological studies indicate that our results are representative of the overall population of MS patients in Germany.

Finally, it must be noted that the MS registry was cross-sectional in design and can only describe patterns of care from this perspective; data on the course of disease before treatment are not available. As result, it is impossible to compare the effectiveness of the different treatment options. This will be possible only after data from the follow-up studies, currently under planning, have become available.

Despite these limitations, the MS registry provides valuable information on patterns of care for MS patients in Germany. This will help in the development of targeted approaches to addressing inadequate and inappropriate care and thus improve patients' quality of life. In addition, the German MS registry will serve as the basis for a Europe-wide MS register to be developed under the auspices of the European Multiple Sclerosis Platform (EMSP) and being supported by the European Union.

The project was conducted under the auspices of MS-Forschungs- und Projektentwicklungs-gGmbH together with DMSG Bundesverband e.V.
The MS registry was financed by the German Multiple Sclerosis Foundation (Deutschen-Multiple-Sklerose-Stiftung), the official foundation of the DMSG. The German Multiple Sclerosis Foundation receives donations from private individuals, organizations, and the pharmaceutical industry. The substance of the projects is not influenced by these donations.

For further information about participating in the registry please contact:
Kristin Stuke, Project Coordinator, MSFP, Küsterstraße 8, 30519 Hannover, Germany; Tel: +49 511 968 34-25, Fax: +49 511 968 34-50, stuke@dmsg.de.

A list of the currently participating centers is available on the DMSG website (www.dmsg.de).

Conflict of interest statement
Prof. Haas reports receiving lecture and consulting fees, as well as research support, from Teva, Sanofi-Aventis, Bayer-Schering, Novartis, Biogen,
Merck-Serono, Allergan, Octapharma, and Talekris.
PD Dr. Flachenecker reports receiving lecture fees from Bayer-Schering, Merck-Serono, Biogen, Sanofi-Aventis, and Novartis.
Dr. Wolfgang Elias reports receiving financial support from Biogen,
Bayer-Schering, Sanofi-Aventis, and Merck-Serono.
Mr. Freidel has received lecture and consulting fees, research support, and travel expense reimbursement from Bayer-Schering, Merck-Serono, Biogen, and Teva, among others.
Prof. Rieckmann reports receiving lecture fees from Bayer-Schering, Biogen, Novartis, Teva, Berlex, Merck-Serono, Sanofi-Aventis, and Almiral.
Prof. Zettl reports receiving lecture fees from Biogen, Bayer-Schering,
Merck-Serono, Teva, and Sanofi-Aventis.
Mrs. Pitschnau-Michel, M. A., Mrs. Stuke, Ph.D., Dipl.-Biol., and Dr. Schimrigk declare that no conflict of interest exists according to the guidelines of the International Committee of Medical Journal Editors.

Manuscript received on 2 October 2006; revised version accepted on
30 October 2007

Translated from the original German by Matthew D. Gaskins.


Corresponding author
PD Dr. med. Peter Flachenecker
Neurologisches Rehabilitationszentrum Quellenhof
Kuranlagenallee 2
75323 Bad Wildbad, Gemany
peter.flachenecker@quellenhof.de
1.
Flachenecker P, Zettl UK: Epidemiologie. In: Schmidt RM, Hoffmann F (eds.): Multiple Sklerose. München: Urban & Fischer 2006; 11–17.
2.
Kobelt G, Berg J, Lindgren P et al.: Costs and quality of life of multiple sclerosis in Germany. Eur J Health Econ 2006; 7 (Suppl. 2): S34–S44. MEDLINE
3.
Flachenecker P, Zettl UK, Götze U et al.: MS Register in Deutschland – Design und erste Ergebnisse der Pilotphase. Nervenarzt 2005; 76: 967–75. MEDLINE
4.
Kurtzke JF: Rating neurologic impairment in multiple sclerosis: an expanded disability status scale (EDSS). Neurology 1983; 33: 1444–52. MEDLINE
5.
Flachenecker P, Zettl UK: Krankheitsverlauf und Prognose. In: Schmidt RM, Hoffmann F (eds.): Multiple Sklerose. München: Urban & Fischer 2006; 61–70.
6.
Haas J, Kugler J, Nippert I, Pöhlau D, Scherer P: Lebensqualität bei Multipler Sklerose. Berliner DMSG-Studie. Berlin: de Gruyter 2003.
7.
Kobelt G, Lindgren P, Smala A et al.: Cost and quality of life in multiple sclerosis. An observational study in Germany. Health Econom Prevent Care 2001; 2: 60–8.
8.
Pittock SJ, Mayr WT, McClelland RL et al.: Change in MS-related disability in a population-based cohort: a 10-year follow-up study. Neurology 2004; 62: 51–9. MEDLINE
9.
Weinshenker BG, Bass B, Rice GP et al.: The natural history of multiple sclerosis: a geographically based study. 1. Clinical course and disability. Brain 1989; 112: 133–46. MEDLINE
10.
Rodriguez M, Siva A, Ward J, Stolp Smith K, O'Brien P, Kurland L: Impairment, disability, and handicap in multiple sclerosis: a population-based study in Olmsted County, Minnesota. Neurology 1994; 44: 28–33. MEDLINE
11.
Tremlett H, Paty D, Devonshire V: Disability progression in multiple sclerosis is slower than previously reported. Neurology 2006; 66: 172–7. MEDLINE
12.
Confavreux C, Vukusic S, Moreau T, Adeleine P: Relapses and progression of disability in multiple sclerosis. N Engl J Med 2000; 343: 1430–8. MEDLINE
13.
Tremlett H, Devonshire V: Is late-onset multiple sclerosis associated with a worse outcome? Neurology 2006; 67: 954–9. MEDLINE
14.
Polman CH, Reingold SC, Edan G et al.: Diagnostic criteria for multiple sclerosis. 2005 revisions to the „McDonald criteria“. Ann Neurol 2005; 58: 840–6. MEDLINE
15.
Marrie RA, Cutter G, Tyry T, Hadjimichael O, Campagnolo D, Vollmer T: Changes in the ascertainment of multiple sclerosis. Neurology 2005; 65: 1066–70. MEDLINE
16.
Rieckmann P, Toyka KV: Multiple Sklerose Therapie Konsensus Gruppe. Diagnostik und Therapie der Multiplen Sklerose. In: Kommission „Leitlinien“ der Deutschen Gesellschaft für Neurologie (ed.): Leitlinien für Diagnostik und Therapie in der Neurologie. Stuttgart, New York: Georg Thieme Verlag 2005; 298–316.
17.
Multiple Sklerose Therapie Konsensus Gruppe: Immunmodulatorische Stufentherapie der multiplen Sklerose. Neue Aspekte und praktische Umsetzung, März 2002. Nervenarzt 2002; 73: 556–3.
18.
Pittock SJ, Mayr WT, McClelland RL et al.: Disability profile of MS did not change over 10 years in a population-based prevalence cohort. Neurology 2004; 62: 601–6. MEDLINE
19.
Smith MM, Arnett PA: Factors related to employment status changes in individuals with multiple sclerosis. Mult Scler 2005; 11: 602–9. MEDLINE
20.
O'Connor RJ, Cano SJ, Torrenta L, Thompson AJ, Playford ED: Factors influencing work retention for people with multiple sclerosis: cross-sectional studies using qualitative and quantitative methods. J Neurol 2005; 252: 892–6. MEDLINE
21.
Lo AC, Hadjimichael O, Vollmer TL: Treatment patterns of multiple sclerosis patients: a comparison of veterans and non-veterans using the NARCOMS registry. Mult Scler 2005; 11: 33–40. MEDLINE
22.
Multiple Sklerose Therapie Konsensus Gruppe: Immunmodulatorische Stufentherapie der multiplen Sklerose. Nervenarzt 1999; 70: 371–86. MEDLINE
23.
Multiple Sklerose Therapie Konsensus Gruppe: Immunmodulatorische Stufentherapie der multiplen Sklerose. 1. Ergänzung: Dezember 2000. Nervenarzt 2001; 72: 150–7. MEDLINE
24.
Multiple Sklerose Therapie Konsensus Gruppe: Symptomatic treatment of multiple sclerosis. Eur Neurol 2006; 56: 78–105. MEDLINE
25.
Multiple Sklerose Therapie Konsensus Gruppe, Rieckmann P: Immunmodulatorische Stufentherapie der Multiplen Sklerose: Update September 2006. Nervenarzt 2006; 77: 1506–18. MEDLINE
Neurologisches Rehabilitationszentrum Quellenhof Bad Wildbad: PD Dr. med. Flachenecker, Neurologische Universitätsklinik Würzburg: PD Dr. med. Flachenecker, Prof. Dr. med. Rieckmann, MS-Forschungs- und Projektentwicklungs-gGmbH Hannover: Stuke,
Neurologische Schwerpunktpraxis Hamburg: Dr. med. Elias,
Neurologische Schwerpunktpraxis Kaltenkirchen: Freidel,
Jüdisches Krankenhaus Berlin: Prof. Dr. med. Haas, DMSG Bundesverband e.V. Hannover: Pitschnau-Michel, Klinik für Neurologie des Klinikums Lüdenscheid: Dr. med. Schimrigk, Klinik für Neurologie der Universität Rostock: Prof. Dr. med. Zettl
1. Flachenecker P, Zettl UK: Epidemiologie. In: Schmidt RM, Hoffmann F (eds.): Multiple Sklerose. München: Urban & Fischer 2006; 11–17.
2. Kobelt G, Berg J, Lindgren P et al.: Costs and quality of life of multiple sclerosis in Germany. Eur J Health Econ 2006; 7 (Suppl. 2): S34–S44. MEDLINE
3. Flachenecker P, Zettl UK, Götze U et al.: MS Register in Deutschland – Design und erste Ergebnisse der Pilotphase. Nervenarzt 2005; 76: 967–75. MEDLINE
4. Kurtzke JF: Rating neurologic impairment in multiple sclerosis: an expanded disability status scale (EDSS). Neurology 1983; 33: 1444–52. MEDLINE
5. Flachenecker P, Zettl UK: Krankheitsverlauf und Prognose. In: Schmidt RM, Hoffmann F (eds.): Multiple Sklerose. München: Urban & Fischer 2006; 61–70.
6. Haas J, Kugler J, Nippert I, Pöhlau D, Scherer P: Lebensqualität bei Multipler Sklerose. Berliner DMSG-Studie. Berlin: de Gruyter 2003.
7. Kobelt G, Lindgren P, Smala A et al.: Cost and quality of life in multiple sclerosis. An observational study in Germany. Health Econom Prevent Care 2001; 2: 60–8.
8. Pittock SJ, Mayr WT, McClelland RL et al.: Change in MS-related disability in a population-based cohort: a 10-year follow-up study. Neurology 2004; 62: 51–9. MEDLINE
9. Weinshenker BG, Bass B, Rice GP et al.: The natural history of multiple sclerosis: a geographically based study. 1. Clinical course and disability. Brain 1989; 112: 133–46. MEDLINE
10. Rodriguez M, Siva A, Ward J, Stolp Smith K, O'Brien P, Kurland L: Impairment, disability, and handicap in multiple sclerosis: a population-based study in Olmsted County, Minnesota. Neurology 1994; 44: 28–33. MEDLINE
11. Tremlett H, Paty D, Devonshire V: Disability progression in multiple sclerosis is slower than previously reported. Neurology 2006; 66: 172–7. MEDLINE
12. Confavreux C, Vukusic S, Moreau T, Adeleine P: Relapses and progression of disability in multiple sclerosis. N Engl J Med 2000; 343: 1430–8. MEDLINE
13. Tremlett H, Devonshire V: Is late-onset multiple sclerosis associated with a worse outcome? Neurology 2006; 67: 954–9. MEDLINE
14. Polman CH, Reingold SC, Edan G et al.: Diagnostic criteria for multiple sclerosis. 2005 revisions to the „McDonald criteria“. Ann Neurol 2005; 58: 840–6. MEDLINE
15. Marrie RA, Cutter G, Tyry T, Hadjimichael O, Campagnolo D, Vollmer T: Changes in the ascertainment of multiple sclerosis. Neurology 2005; 65: 1066–70. MEDLINE
16. Rieckmann P, Toyka KV: Multiple Sklerose Therapie Konsensus Gruppe. Diagnostik und Therapie der Multiplen Sklerose. In: Kommission „Leitlinien“ der Deutschen Gesellschaft für Neurologie (ed.): Leitlinien für Diagnostik und Therapie in der Neurologie. Stuttgart, New York: Georg Thieme Verlag 2005; 298–316.
17. Multiple Sklerose Therapie Konsensus Gruppe: Immunmodulatorische Stufentherapie der multiplen Sklerose. Neue Aspekte und praktische Umsetzung, März 2002. Nervenarzt 2002; 73: 556–3.
18. Pittock SJ, Mayr WT, McClelland RL et al.: Disability profile of MS did not change over 10 years in a population-based prevalence cohort. Neurology 2004; 62: 601–6. MEDLINE
19. Smith MM, Arnett PA: Factors related to employment status changes in individuals with multiple sclerosis. Mult Scler 2005; 11: 602–9. MEDLINE
20. O'Connor RJ, Cano SJ, Torrenta L, Thompson AJ, Playford ED: Factors influencing work retention for people with multiple sclerosis: cross-sectional studies using qualitative and quantitative methods. J Neurol 2005; 252: 892–6. MEDLINE
21. Lo AC, Hadjimichael O, Vollmer TL: Treatment patterns of multiple sclerosis patients: a comparison of veterans and non-veterans using the NARCOMS registry. Mult Scler 2005; 11: 33–40. MEDLINE
22. Multiple Sklerose Therapie Konsensus Gruppe: Immunmodulatorische Stufentherapie der multiplen Sklerose. Nervenarzt 1999; 70: 371–86. MEDLINE
23. Multiple Sklerose Therapie Konsensus Gruppe: Immunmodulatorische Stufentherapie der multiplen Sklerose. 1. Ergänzung: Dezember 2000. Nervenarzt 2001; 72: 150–7. MEDLINE
24. Multiple Sklerose Therapie Konsensus Gruppe: Symptomatic treatment of multiple sclerosis. Eur Neurol 2006; 56: 78–105. MEDLINE
25. Multiple Sklerose Therapie Konsensus Gruppe, Rieckmann P: Immunmodulatorische Stufentherapie der Multiplen Sklerose: Update September 2006. Nervenarzt 2006; 77: 1506–18. MEDLINE