by Richard Hughes
A massive study of the global burden of disease has been published in the most recent issue of the Lancet (Horton 2012). It reports the mortality, causes of death, years lived with disability and disability-adjusted life years for 291 conditions in 21 regions taking into account 67 risk factors. Between 1990 and 2010 the world population has risen from 3.7 to 6.9 billion people. With rare exceptions (sadly including our members, Belarus and Ukraine), global life expectancy has risen throughout the world from an average of 56.4 years in 1970 to 67.5 years in 2010 for males and from 61.2 years to 73.3 years for females. The logistical task in collecting this information was formidable. They used novel statistics to make the best possible estimates of averages and their uncertainty intervals (as they appropriately label what we usually call confidence intervals). Summarising the results would be too ambitious but here are some neurological nuggets. Worldwide, stroke remains the second commonest cause of death after ischaemic heart disease and ahead of chronic obstructive pulmonary disease and the third commonest cause of years of life lost, behind both of these (Lozano et al 2012). Average annual mortality due to other neurological diseases was 18.8/100,000, including Alzheimer’s disease and other dementias 7.1/100,000 and Parkinson’s disease 1.7/100,000.
Life expectancy has increased worldwide and there has been a small fall in years lived with disability per 100,000. Nevertheless, since the world population has both grown and become older, the total years lived with disability has increased by one third. Migraine ranked 8th, epilepsy 20th and Alzheimer’s disease 24th in a table of the prevalence of all diseases measured in years lived with disability. Low back pain was 1st and major depressive disorder 2nd in the same table. To these estimates must be added the neurological components of head injury, diseases causing blindness and deafness and systemic illnesses with neurological features such as peripheral neuropathy in diabetes. It is no surprise to us that near the top of the list of the 50 commonest symptoms of disease were tension type headache affecting 20.77% and migraine 14.70% of the world population (Vos et al 2012). Years of life lost due to premature mortality and years lived with disability can be combined to create Disability Adjusted Life Years. With this as a measure the burden of neurological disease is striking. Stroke remains in third place in the rank order of all diseases, with 1484 Disability Adjusted Life Years/100,000 population and other neurological disorders 1071/100,000 (Murray et al 2012).
We know from the European Brain Council and EFNS sponsored study that the annual cost of brain disease in Europe was 798 billion Euros in 2010 (Gustavsson et al. 2011). Combining the European costs with the figures for global incidence and prevalence, the worldwide cost of neurological disease is likely to be an order of magnitude greater. The EFNS, and the future EAN, should be ensuring that healthcare planners take note of this cost and the need for investment in research to reduce the burden.
References
Gustavsson, A., Svensson, M., Jacobi, F., Allgulander, C., Alonso, J., Beghi, E., Dodel, R., Ekman, M., Faravelli, C., Fratiglioni, L., Gannon, B., Jones, D.H., Jennum, P., Jordanova, A., Jonsson, L., Karampampa, K., Knapp, M., Kobelt, G., Kurth, T., Lieb, R., Linde, M., Ljungcrantz, C., Maercker, A., Melin, B., Moscarelli, M., Musayev, A., Norwood, F., Preisig, M., Pugliatti, M., Rehm, J., Salvador-Carulla, L., Schlehofer, B., Simon, R., Steinhausen, H.C., Stovner, L.J., Vallat, J.M., den Bergh, P.V., van, O.J., Vos, P., Xu, W., Wittchen, H.U., Jonsson, B., & Olesen, J. 2011. Cost of disorders of the brain in Europe 2010. Eur. Neuropsychopharmacol., 21, (10) 718-779 available from: PM:21924589
Horton, Lozano et al., Vos et al., Murray et al. are published in The Lancet, 2012 December, 380, 2053-2260.
