title: Trends of diabetic nephropathy prevalence in Isfahan, Iran, during 1992-2010.
abstract: BACKGROUND
  Diabetes mellitus is a metabolic disorder and its subsequent complications such as retinopathy, nephropathy, ulcers, disability, and amputation increase the burden of the disease. Patient knowledge-improving programs are employed to prevent disease progression and to improve the quality of life of the patients. In this way, we need to characterize the groups of patients in urgent need for more and rich-in-content programs. In the present study, we used piecewise regression to evaluate the trends of diabetic nephropathy prevalence in patients registered in the Sedigheh-Tahereh Research Center and to identify patients who were in need of more attention.
  
  
  METHODS
  Piecewise regression, used in this study, is a statistical method to identify change points, if any, in the trends of mortality rates, prevalence of a disease, or any other trends. Available information for 1,935 patients were retrieved from the database. Joinpoint program 3.5.3 and Statistical Package for the Social Sciences (SPSS) 20 was used to fit piecewise regression and obtain descriptive statistics, respectively.
  
  
  RESULTS
  We assessed the trend of diabetic nephropathy in different groups of diabetic patients with respect to sex, blood pressure status, education, family history of diabetes, and age. The results showed an increasing trend in females, patients without family history of diabetes, and eover th recent years. The prevalence of diabetic nephropathy in patients with academic education was high.
  
  
  CONCLUSIONS
  The groups with high prevalence or increasing trends need more preventive intervention and detailed assessment of the present trends. Exploring high-risk groups is beneficial for better policy-making in the future. However, discovering the reasons for the increased trend of the disease is really helpful in controlling diabetes complications.
authors.affiliation: Department of Biostatistics and Epidemiology, Kermanshah University of Medical Sciences, Kermanshah, Iran; Department of Statistics and Epidemiology, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Tohid
authors.initials: T
authors.lastname: Jafari-Koshki
authors.affiliation: Skin Diseases and Leishmaniasis Research Center, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Biostatistics and Epidemiology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Sayed Mohsen
authors.initials: SM
authors.lastname: Hosseini
authors.affiliation: Department of Epidemiology and Biostatistics, School of Health, Qom University of Medical Sciences, Qom, Iran.
authors.forename: Shahram
authors.initials: S
authors.lastname: Arsang-Jang
authors.affiliation: Department of Internal Medicine, Isfahan Endocrinology and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Amini
authors.affiliation: Department of Internal Medicine, Isfahan Endocrinology and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Faghihimani
keywords: Diabetic nephropathy; piecewise regression; prevalence; trend