Figure 3From: Effect of primary care physicians' use of estimated glomerular filtration rate on the timing of their subspecialty referral decisions Recommended serum creatinine and estimated glomerular filtration rate (eGFR)-based referral levels by primary care providers. Note. Lines and bars represent the range and interquartile range of selected values, respectively. Abbreviations. eGFR, estimated glomerular filtration rateBack to article page