Limitations
This study had some limitations. Working with Persian textual data in R and Rstudio statistical program was so difficult and complicated. Using multi packages and programming many codes almost reduce this limitation, but it took a long time to run for cleaning and classifying information from large data volumes. Another limitation was the incomplete or inaccurate records of patient information in HIS, which modified or deleted from study. Double coding in the use of ICD-10 diagnostic codes to distinguish CVDs was another limitation of this study.