title: Main Determinants of Supplementary Health Insurance Demand: (Case of Iran).
abstract: BACKGROUND
  In the majority of developing countries, the volume of medical insurance services, provided by social insurance organizations is inadequate. Thus, supplementary medical insurance is proposed as a means to address inadequacy of medical insurance. Accordingly, in this article, we attempted to provide the context for expansion of this important branch of insurance through identification of essential factors affecting demand for supplementary medical insurance.
  
  
  METHODS
  In this study, two methods were used to identify essential factors affecting choice of supplementary medical insurance including Classification and Regression Trees (CART) and Bayesian logit. To this end, Excel® software was used to refine data and R® software for estimation. The present study was conducted during 2012, covering all provinces in Iran. Sample size included 18,541 urban households, selected by Statistical Center of Iran using 3-stage cluster sampling approach. In this study, all data required were collected from the Statistical Center of Iran.
  
  
  RESULTS
  In 2012, an overall 8.04% of the Iranian population benefited from supplementary medical insurance. Demand for supplementary insurance is a concave function of age of the household head, and peaks in middle-age when savings and income are highest. The present study results showed greater likelihood of demand for supplementary medical insurance in households with better economic status, higher educated heads, female heads, and smaller households with greater expected medical expenses, and household income is the most important factor affecting demand for supplementary medical insurance.
  
  
  CONCLUSIONS
  Since demand for supplementary medical insurance is hugely influenced by households' economic status, policy-makers in the health sector should devise measures to improve households' economic or financial access to supplementary insurance services, by identifying households in the lower economic deciles, and increasing their financial ability to pay. Moreover, insurance companies should adjust their insurance policy according to clients' needs, household characteristics, and their incomes.
authors.affiliation: Department of Health Economics, School of Health Management and Information Sciences, Iran University of Medical Sciences, Tehran, Iran. mania0508@yahoo.com.
authors.forename: Soraya
authors.initials: S
authors.lastname: Nouraei Motlagh
authors.forename: Hassan
authors.initials: H
authors.lastname: Abolghasem Gorji
authors.forename: Ghadir
authors.initials: G
authors.lastname: Mahdavi
authors.forename: Hossein
authors.initials: H
authors.lastname: Ghaderi
mesh_terms: D001499:Bayes Theorem; D003710:Demography; D005382:Financing, Personal / Q000191:economics; D005102:Health Expenditures; D006801:Humans; D007348:Insurance, Health / Q000191:economics*; D007492:Iran; D012959:Socioeconomic Factors; D012984:Software