title: The impact of preventive health behaviour and social factors on visits to the doctor.
abstract: BACKGROUND
  The aim of this study is to examine the joint impact of preventive health behavior (PHB) and social and demographic factors on the utilization of primary and secondary medical care under a universal health care system, as measured by visits to the doctor, who were categorized as either a General Practitioner (GP) or Specialist Doctor (SD).
  
  
  METHODS
  An ordered probit model was utilized to analyze data obtained from the 2009 Israeli National Health Survey. The problem of endogeneity between PHB factors and visits to GP was approached using the two-stage residuals inclusion and instrumental variables method.
  
  
  RESULTS
  We found a positive effect of PHB on visits to the doctor while the addition of the PHB factors to the independent variables resulted in important changes in explaining visits to GP (in values of the estimates, in their sign, and in their statistical significance), and only in slight changes for visits to SD. A 1% increase in PHB factors results in increasing the probability to visit General Practitioner in the last year in 0.6%. The following variables were identified as significant in explaining frequency of visits to the doctor: PHB, socio-economic status (pro-poor for visits to GP, pro-rich for visits to SD), location (for visits to SD), gender, age (age 60 or greater being a negative factor for visits to GP and a positive factor for visits to SD), chronic diseases, and marital status (being married was a negative factor for visits to GP and a positive factor for visits to SD).
  
  
  CONCLUSIONS
  There is a need for allowing for endogeneity in examining the impact of PHB, social and demographic factors on visits to GP in a population under universal health insurance. For disadvantaged populations with low SES and those living in peripheral districts, the value of IndPrev is lower than for populations with high SES and living in the center of the country. Examining the impact of these factors, significant differences in the importance and sometimes even in the sign of their influence on visits to different categories of doctors - GP and SD, are found.
authors.affiliation: The Open University of Israel, Raanana, Israel, Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Gregory
authors.initials: G
authors.lastname: Yom Din
authors.affiliation: Kazrin, Israel.
authors.forename: Zinaida
authors.initials: Z
authors.lastname: Zugman
authors.affiliation: McGill University Health Center, Montreal, Canada.
authors.forename: Alla
authors.initials: A
authors.lastname: Khashper
keywords: Endogeneity; Ordered probit; Preventive health behavior; Universal health care; Visits to the doctor