In 2002, the National Kidney Foundation published treatment guidelines that identified five stages of Chronic Kidney Disease (CKD) based on declining GFR measurements. The guidelines recommend different actions based on the stage of kidney disease.
CSV (Comma Separated Value) was a file format devised to store tabular data. It uses commas to separate each entry in a row and the newline symbol to go to the next row. Excel is a more recent spreadsheet application from Microsoft and it saves the data with its own file format.
However, in popular usage CSV is not a single, well-defined format. As a result, in practice the term CSV might refer to any file that: 1  is plain text using a character set such as ASCII, various Unicode character sets (e.g. UTF-8), EBCDIC, or Shift JIS, 2  consists of records (typically one record per line),