Background. MS incidence has increased among females, suggesting the presence of environmental effect. Object. Regional differences and temporal changes in gender-specific MS incidence were studied in Finland. Methods. Cases from Jan 1, 1981 to Dec 31, 2010 in Pirkanmaa, Seinäjoki and Vaasa districts were included. The standardized incidence rates (SIR), incidences per 105 person years with 95% confidence intervals (CI), and female-to-male ratios (F/M) were determined by district. Results. 1617 cases were included. Compared to Pirkanmaa, the MS risk was 1.9-fold (95% CI: 1.7–2.0) greater in Seinäjoki and 1.2-fold (95% CI: 1.1–1.4) in Vaasa, and the risk was high for both genders. The incidence trend stabilized in Seinäjoki and Vaasa, accompanied by an increase in the F/M ratio. A steady increase in Pirkanmaa was accompanied by a high F/M ratio. Conclusion. A high female preponderance accompanied a general increase in incidence since the 1990s, suggesting the influence of environmental factors. In high-risk districts, increased MS risk prevailed in both genders. High risk reflects both genetic and environmental effects. These effects may be shared with autoimmune diseases such as type 1 diabetes mellitus; the incidence of which follows MS in Finland. Population-based case-control studies are needed to identify these factor effects.

Object. Gender and disease course specific incidences were studied in high- and medium-risk regions of MS in Finland. Methods. Age- and gender-specific incidences with 95% CIs were calculated in 10-year periods from 1981 to 2010. Poser diagnostic criteria were used and compared with the McDonald criteria from 2001 to 2010. Association between age and diagnostic delay over time was assessed by using the Kruskal-Wallis test. Results. 1419 (89%) RRMS and 198 (11%) PPMS cases were included. RRMS incidence increased with the female to male ratio (F/M) from 4,2/105 (F/M 1.9) to 9,7 (2.3), while that of PPMS decreased from 1,2 (1.6) to 0,7 (1.2). The use of McDonald criteria did not change the conclusion. The decreasing diagnostic delay and age at diagnosis in RRMS were associated within the 10-year periods and contrasted those in PPMS. Increasing female risk in RRMS was observed in the high-risk region. Conclusion. Increasing RRMS incidence and high female ratios shown in each age group indicate gender-specific influences acting already from childhood. A more precise definition of the risk factors and their action in MS is needed to provide a better understanding of underlying pathological processes and a rationale for the development of new preventive and treatment strategies.

The objective of this study was to assess long-term use, adherence and efficacy of injectable disease modifying agents (DMAs). Multiple Sclerosis (MS) patients diagnosed during 2002-2010 with early treatment start and at least one year in first choice medication were included in a large university district in Finland. Annualized relapse rates (ARR) during each treatment period were studied, and number of switches by medication evaluated. Use of health care facilities during 2002-2010 was assessed. In the study were included 113 MS patients; 15 (13%) switched medication. The mean duration of treatment period (128) was 3.8 years. In 77% (98/128) the treatment continued with the first DMA for (mean) 3.8 years, in 19% (25/128) with the second for 3.5 years and in 4% (5/128) with the third for 4.8 years. Mean ARR was 0.26, with 54% (69/128) of the periods relapse free. Mean ARR during the treatment periods with product switch was 0.41 before, and 0.28 after the switch, showing a trend towards better efficacy with the second DMA. The usage of health care resources remained within the guidelines. Long-term adherence to first choice DMA was observed, and a switch of product within the DMAs showed continuous adherence and efficacy. The efforts to seek a clinically effective and well tolerated agent within the first-line DMAs is warranted, leading to continued adherence and increased clinical effectiveness.