Comorbidity in multiple sclerosis patients from Nordland County, Norway - validated data from the Norwegian Patient Registry

Postponed access: the file will be available after 2021-12-21Background: Knowledge of comorbid disorders is important to optimize therapy for multiple sclerosis (MS), but data are limited. The aim of this study was to assess comorbidity in persons with MS living in Nordland County on January 1, 2017. Methods: Data were retrieved from the Norwegian Patient Registry (2008-2017) and validated through review of electronic hospital charts (1970-2017). Comorbidity was defined as any distinct disorder, classified in the International Classification of Diseases (ICD-10), that had existed or occurred after the diagnosis of MS was established. Results: Data from 637 subjects were reviewed, and 97.5% were registered with at least one comorbid condition. Malignant melanoma was found in 0.5%, and non-melanoma skin cancers in 1.9%. In female subjects, breast cancer was found in 3.3%. Hypothyroidism was confirmed in 3.1%, type-1 diabetes in 0.3%, type-2 diabetes in 3.9%, psychosis in 0.6%, epilepsy in 2.8%, myocardial infarction in 1.7%, subarachnoid hemorrhage in 0.2%, cerebral infarction in 0.6%, pulmonary embolism in 0.9%, inflammatory bowel disease in 1.3%, and rheumatoid arthritis in 0.6%. Conclusion: Compared to reports from other Norwegian epidemiological studies, a higher proportion of inflammatory bowel disease and epilepsy was found. This is in accordance with findings from other studies. The prevalence of non-melanoma skin cancers was significantly higher than in the general Norwegian population as they were reported by The Cancer Registry of Norway.acceptedVersio

Month of birth and risk of multiple sclerosis: confounding and adjustments

A month of birth effect on multiple sclerosis (MS) risk has been reported from different countries. Recent critics have suggested that this finding is caused by confounding and that adequately adjusting for year and place of birth would markedly reduce this effect. All inhabitants in Norway are registered in the Norwegian Population Registry (Statistics Norway), making this an ideal area for performing adjusted analyses. Using the entire Norwegian population born between 1930 and 1979 (n = 2,899,260), we calculated the excess between observed and expected number of births for each month for 6649 Norwegian MS patients, 5711 mothers, 5247 fathers, and 8956 unaffected siblings. The analyses were adjusted for year of birth and place of birth according to the 19 counties in Norway. An unadjusted analysis revealed 13% fewer MS births than expected in February (P = 0.0015; Bonferroni corrected P = 0.018), 10% more in April (P = 0.0083; Bonferroni corrected P = 0.0996) and 15% more in December (P = 0.00058; Bonferroni corrected P = 0.007). Adjustments for both year and place of birth significantly altered our results for February and December, but even after these adjustments there were still 10% more MS births than expected in April (P = 0.00796; Bonferroni corrected P = 0.096). MS patients had a higher incidence of April births than their siblings (Fisher-exact test; P = 0.011), mothers (Fisher-exact test; P = 0.004), and fathers (Fisher-exact test; P = 0.011) without MS. Adjustments for confounding significantly affected our results. However, even after adjustments, there appears to be a persistent higher than expected frequency of April births in the MS population. © 2014 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals, Inc on behalf of American Neurological Association

The Effect of Smoking on Long-term Gray Matter Atrophy and Clinical Disability in Patients with Relapsing-Remitting Multiple Sclerosis

The relationship between smoking, long-term brain atrophy, and clinical disability in patients with multiple sclerosis (MS) is unclear. Here, we assessed long-term effects of smoking by evaluating MRI and clinical outcome measures after 10 years in smoking and nonsmoking patients with relapsing-remitting MS (RRMS).publishedVersio

Serum neurofilament as a predictor of 10-year grey matter atrophy and clinical disability in multiple sclerosis: a longitudinal study

Background The predictive value of serum neurofilament light chain (sNfL) on long-term prognosis in multiple sclerosis (MS) is still unclear. Objective Investigate the relation between sNfL levels over a 2-year period in patients with relapsing-remitting MS, and clinical disability and grey matter (GM) atrophy after 10 years. Methods 85 patients, originally enrolled in a multicentre, randomised trial of ω−3 fatty acids, participated in a 10-year follow-up visit. sNfL levels were measured by Simoa quarterly until month 12, and then at month 24. The appearance of new gadolinium-enhancing (Gd+) lesions was assessed monthly between baseline and month 9, and then at months 12 and 24. At the 10-year follow-up visit, brain atrophy measures were obtained using FreeSurfer. Results Higher mean sNfL levels during early periods of active inflammation (Gd+ lesions present or recently present) predicted lower total (β=−0.399, p=0.040) and deep (β=−0.556, p=0.010) GM volume, lower mean cortical thickness (β=−0.581, p=0.010) and higher T2 lesion count (β=0.498, p=0.018). Of the clinical outcomes, higher inflammatory sNfL levels were associated with higher disability measured by the dominant hand Nine-Hole Peg Test (β=0.593, p=0.004). Mean sNfL levels during periods of remission (no Gd+ lesions present or recently present) did not predict GM atrophy or disability progression. Conclusion Higher sNfL levels during periods of active inflammation predicted more GM atrophy and specific aspects of clinical disability 10 years later. The findings suggest that subsequent long-term GM atrophy is mainly due to neuroaxonal degradation within new lesions.publishedVersio

Time trends in the incidence and prevalence of multiple sclerosis in Norway during eight decades

Norway has been subjected to numerous epidemiological investigations on the prevalence and incidence of multiple sclerosis (MS), dating back to 1935. The objective of this study was to review the studies on the prevalence and incidence of MS in Norway, provide an update on the prevalence of MS in Norway, and describe the time trends in the prevalence and incidence of MS in relation to risk factors, case ascertainment, and data. We performed a systematic search on PubMed and MEDLINE up to November 2014 using the search string ‘multiple sclerosis prevalence in Norway’ or ‘multiple sclerosis incidence in Norway’. In addition, we scrutinized the reference lists of the publications identified for relevant citations. We retrieved data on the distribution of MS in Norway on December 31, 2013 from the Norwegian Multiple Sclerosis Registry and Biobank and the Norwegian Patient Registry. We identified 29 articles. From 1961 to 2014, the reported prevalence of MS increased from 20 to 203 per 100,000 inhabitants, and the incidence increased from 1.9 to 8.0 per 100,000. The nationwide crude prevalence in Norway, based on the Norwegian Patient Registry, was 208 per 100,000 on December 31, 2013. The reported prevalence of MS in Norway has increased 10-fold, with several possible causes. During eight decades, neurological health services have generally become more accessible to the population, and transforming diagnostic criteria has made the diagnosis of MS more precise and valid. There have also been changes in lifestyle behavior and known risk factors, such as vitamin D and smoking, that might have contributed to the increased incidence of MS. A possible role of increased survival in MS needs to be examined further

A 60-year follow-up of the incidence and prevalence of multiple sclerosis in Hordaland County, Western Norway

Objective: Investigate the incidence of multiple sclerosis during 1953–2013 and estimate the prevalence rate of MS on 1 January 2003 and 2013 in Hordaland County, Western Norway. Methods: All patients with onset of disease in Hordaland 1953–2013 were identified in files from previous studies until 2003 and from patient records at the departments of Neurology, Haukeland University Hospital and Haugesund Hospital during 2003–2013. 1558 patients were assessed and 1402 of these were included, of whom 1035 were alive and living in Hordaland at prevalence day 1 January 2013. Annual incidence rates were calculated for 1953–2013. Results: On 1 January 2003, the crude prevalence rate was 191/100 000 population and on 1 January 2013, the crude prevalence rate was 211.4 (95% CI 198.3 to 224.2) per 100 000; 270.9 (95% CI 250.6 to 292.3) for women and 151.8 (95% CI 136.8 to 167.9) for men. Prevalence peaked at ages 55–59 years for women and 60–64 years for men. The annual incidence rate increased from 1.9 (95% CI 1.2 to 2.6) per 100 000 during 1953–1957 to 7.2 (95% CI 6.0 to 8.5) during 1978–1982 and to 8.5 (95% CI 7.3 to 9.7) during 2003–2007, thus indicating a stabilising incidence over the past 35 years. The female/ male ratio ranged from 1.2:1 to 1.8:1 (p=0.381) during the period. Conclusions: Stabilising rather than increasing incidence combined with the stable female/male ratio are indicative of non-fluctuating environmental factors in a geographical area otherwise characterised by lack of vitamin D effective sun exposure. The rising prevalence of MS could result from improved survival and follow-up methodology

Validation of the multiple sclerosis diagnosis in the Norwegian Patient Registry

Background: Health registries may yield important data for epidemiological studies. However, in order to be a valuable source for information, the registered data have to be correct. Objectives: The aim of the study was to validate data from the Norwegian Patient Registry (NPR) regarding multiple sclerosis (MS). Materials and Methods: We obtained data on individuals residing in Nordland County and registered with a MS diagnosis in the NPR or in local hospital records. The NPR data included a unique 11‐digit personal identity number that made it possible to identify the individuals medical records. For each individual registered with MS in the NPR, the hospital record was scrutinized in order to confirm or rule out the diagnosis. Results: In Nordland County, 657 individuals had MS 1 January 2017. Of these, 637 were recorded with a correct diagnosis of MS in the NPR, while 59 were recorded incorrectly. Incorrect registration was due to a diagnosis that did not fulfill the diagnostic criteria, later investigation had ruled out MS or it was an error in the diagnostic code registration process. Twenty individuals were not registered with MS in the NPR. These were patients who received their diagnosis before data in the NPR were person identifiable (before 2008), and who later had no MS‐registered contact with public specialist healthcare services. The sensitivity is 0.97, and the positive predictive value is 0.92. Conclusion: Data from the NPR gave a good estimate of the occurrence of MS, but nearly one in 10 registered diagnoses was not correct

Employment among patients with multiple sclerosis - A population study

To investigate demographic and clinical factors associated with employment in MS.The study included 213 (89.9%) of all MS patients in Sogn and Fjordane County, Western Norway at December 31st 2010. The patients underwent clinical evaluation, structured interviews and completed self-reported questionnaires. Demographic and clinical factors were compared between patients being employed versus patients being unemployed and according to disease course of MS. Logistic regression analysis was used to identify factors independently associated with current employment.After a mean disease duration of almost 19 years, 45% of the population was currently full-time or part- time employed. Patients with relapsing -remitting MS (RRMS) had higher employment rate than patients with secondary (SPMS) and primary progressive (PPMS). Higher educated MS patients with lower age at onset, shorter disease duration, less severe disability and less fatigue were most likely to be employed.Nearly half of all MS patients were still employed after almost two decades of having MS. Lower age at onset, shorter disease duration, higher education, less fatigue and less disability were independently associated with current employment. These key clinical and demographic factors are important to understand the reasons to work ability in MS. The findings highlight the need for environmental adjustments at the workplace to accommodate individual 's needs in order to improve working ability among MS patients

Validation of the multiple sclerosis diagnosis in the Norwegian Patient Registry

Background - Health registries may yield important data for epidemiological studies. However, in order to be a valuable source for information, the registered data have to be correct. Objectives - The aim of the study was to validate data from the Norwegian Patient Registry (NPR) regarding multiple sclerosis (MS). Materials and Methods - We obtained data on individuals residing in Nordland County and registered with a MS diagnosis in the NPR or in local hospital records. The NPR data included a unique 11‐digit personal identity number that made it possible to identify the individuals medical records. For each individual registered with MS in the NPR, the hospital record was scrutinized in order to confirm or rule out the diagnosis. Results - In Nordland County, 657 individuals had MS 1 January 2017. Of these, 637 were recorded with a correct diagnosis of MS in the NPR, while 59 were recorded incorrectly. Incorrect registration was due to a diagnosis that did not fulfill the diagnostic criteria, later investigation had ruled out MS or it was an error in the diagnostic code registration process. Twenty individuals were not registered with MS in the NPR. These were patients who received their diagnosis before data in the NPR were person identifiable (before 2008), and who later had no MS‐registered contact with public specialist healthcare services. The sensitivity is 0.97, and the positive predictive value is 0.92. Conclusion - Data from the NPR gave a good estimate of the occurrence of MS, but nearly one in 10 registered diagnoses was not correct