title: National and sub-national trend of prevalence and burden of dementia in Iran, from 1990 to 2013; study protocol.
abstract: BACKGROUND
  Dementia is a disabling syndrome, which generally affects aged population more than any other age groups. This syndrome has a growing prevalence and incidence worldwide. The prevalence and burden of this group of diseases in Iran have not been estimated in a community-based study yet. This paper aims to explain the systematic approach, data sources, research methodology, and statistical analysis that will be used to quantify the prevalence and burden of dementia at national and sub-national levels.
  
  
  METHODS
  This is the protocol of a secondary data study that explains the design and method of conducting the study. We will use several sources of data that will include a systematic review of articles and gray literature which have reported the prevalence or incidence of dementia and its uncertainty at national and sub-national levels in Iran, in addition to data about dementia-specific drug sales per each year at provincial levels, as well as data extracted from 23 million health insurance prescriptions over 8 years and some data from medical documents of Iranian Alzheimer's Association members. The technical groups of National and Sub-national Burden of Disease will collect some covariate data, such as age and sex structure of population, urbanization status, mean years of schooling, plasma cholesterol, fasting plasma glucose, and systolic and diastolic blood pressure at provincial levels which will be used in our models. Two statistical models, namely spatio-temporal and hierarchical autoregressive models, will be used for interpolation and extrapolation of missing data.
  
  
  CONCLUSIONS
  It seems that the study of national and sub-national burden of dementia could provide more accurate estimation of prevalence and burden of dementia in Iran with an acceptable level of uncertainty than the previous studies.
authors.affiliation: 1)Elderly Health Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. 2) Non-Communicable Disease Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.emrc@tums.ac.ir.
authors.forename: Farshad
authors.initials: F
authors.lastname: Sharifi
authors.affiliation: Elderly Health Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Baharak
authors.initials: B
authors.lastname: Najafi
authors.affiliation: Elderly Health Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Fakhrzadeh
authors.affiliation: Geriatric Education Group, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Noroozian
authors.affiliation: Non-Communicable Disease Research Center, Endocrinology and Metabolism Population Sciences Institute. Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Shohreh
authors.initials: S
authors.lastname: Naderimagham
authors.affiliation: Hull and East Yorkshire NHS Hospitals Trust, East Riding of Yorkshire, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Philp
authors.affiliation: Elderly Health Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Masood
authors.initials: SM
authors.lastname: Arzaghi
authors.affiliation: Elderly Health Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahtab
authors.initials: M
authors.lastname: Alizadeh
authors.affiliation: Elderly Health Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Shervan
authors.initials: S
authors.lastname: Shoaee
authors.affiliation: Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran Iran.
authors.forename: Tahereh
authors.initials: T
authors.lastname: Hassannia
authors.affiliation: 6)Department of Biostatistics, Faculty of Paramedical sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2)Non-Communicable Disease Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Sheidaei
authors.affiliation: Community Medicine Department, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Maziar
authors.initials: M
authors.lastname: Moradi-Lakeh
authors.affiliation: 2)Non-Communicable Disease Research Center, Endocrinology and Metabolism Population Sciences Institute. Tehran University of Medical Sciences, Tehran, Iran. 5)Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Farshad
authors.initials: F
authors.lastname: Farzadfar
authors.affiliation: Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran Iran.
authors.forename: Bagher
authors.initials: B
authors.lastname: Larijani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001499:Bayes Theorem; D002648:Child; D002675:Child, Preschool; D002985:Clinical Protocols; D017281:Cost of Illness; D016208:Databases, Factual; D003704:Dementia / Q000453:epidemiology*; D015340:Epidemiologic Research Design; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D055361:Multilevel Analysis; D015995:Prevalence; D012044:Regression Analysis; D062211:Spatio-Temporal Analysis; D000078202:Systematic Reviews as Topic; D055815:Young Adult