title: A retrospective cohort study on factors associated blood pressure using multilevel modeling.
abstract: BACKGROUND
  Hypertension is a health problem in Iran. Given the importance of this subject, we reviewed the factors affecting the blood pressure in this survey.
  
  
  METHODS
  This retrospective cohort study was performed on 3961 male workers employed at Isfahan Polyacryl Corporation (Iran) in health and safety executive between 1996 until 2008. In this study, systolic and diastolic blood pressure (SBP and DBP) were considered as dependent variables; body mass index (BMI), age, type of job, marital status, shift work and educational level were considered as independent variables. MLwiN programmer version 2.1 was used to analyze the data.
  
  
  RESULTS
  BMI, age, shift work, marital status and educational level had statistical significant association with DBP. The result for SBP was similar to DBP except shift work and educational level that had no statistically significant association.
  
  
  CONCLUSIONS
  The results can be considered in the industry to provide practical solutions to reduce blood pressure.
authors.affiliation: PhD Candidate, Department of Biostatistics, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Gholami-Fesharaki
authors.forename: Anoshirvan
authors.initials: A
authors.lastname: Kazemnejad
authors.forename: Farid
authors.initials: F
authors.lastname: Zayeri
authors.forename: Javad
authors.initials: J
authors.lastname: Sanati
authors.forename: Hamed
authors.initials: H
authors.lastname: Akbari
keywords: Blood Pressure; Cohort Study; Multilevel Anal; Retrospective Study; Risk Factor