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.
A CSV is a comma-separated values file, which allows data to be saved in a tabular format. CSVs look like a garden-variety spreadsheet but with a .csv extension. CSV files can be used with most any spreadsheet program, such as Microsoft Excel or Google Spreadsheets.