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Updated: Aug 20, 2026
A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Mortality of multiple sclerosis in Spain: demonstration of a north-South gradient
Javier Llorca1, Paula Guerrero, Dolores Prieto-Salceda
1Division of Preventive Medicine and Public Health, University of Cantabria School of Medicine, Santander, Spain. llorcaj@unican.es
Objective:
To analyse the geographical distribution of multiple sclerosis in Spain from 1975 to 1998.
Methods:
Age-adjusted mortality rates by province were obtained by the indirect method using the whole Spanish population as the reference. Then, standardised mortality ratios (SMRs) and their 95% confidence intervals were estimated.
Results:
For both men and women, provinces with SMRs higher than the mean tended to be in the northern third of Spain, whilst those with SMRs lower than the mean were mostly located in the southern half. A linear regression analysis showed a significant positive association between mortality and latitude.
Conclusion:
A north-south gradient in age-adjusted multiple sclerosis mortality exists in Spain.
