Chronic Kidney Disease Underdiagnosed in Patients with Type 2 Diabetes

Philadelphia—A multicenter, cross-sectional, observational study found that clinicians had a poor record of diagnosing chronic kidney disease (CKD) in patients with type 2 diabetes. Prior to visiting a primary care clinic, only 12.1% of the patients with CKD had been diagnosed with CKD.

Results were presented at the ADA meeting during a late-breaking poster session. The poster was titled Primary Care Detection of CKD in Adults with Type-2 Diabetes in the ADD-CKD Study. Diabetes is the leading cause of CKD, which affects >26 million people in the United States.

The National Kidney Foundation (NKF) conducted the ADD-CKD (Awareness, Detection, and Drug Therapy in Type 2 Diabetes Mellitus and Chronic Kidney Disease) study, which included 9307 patients at 466 primary care sites. Inclusion criteria included ≥18 years of age and a diagnosis of type 2 diabetes for ≥1 year before study visit.

During visits, patients were assessed using a clinician survey, physical exam and medical history, blood samples, urine test, quality of life questionnaires, and a medical record review for laboratory values and concomitant medications.

Patients were categorized in 4 groups: (1) true positive (those who reported they had CKD and were then diagnosed with CKD; n=607), (2) true negative (those who reported they did not have CKD and were then diagnosed as not having CKD; n=4213), (3) false positive (those who reported they had CKD and were then diagnosed as not having CKD; n=58), and (4) false negative (those who reported they did not have CKD and were then diagnosed with CKD; n=4429).

Demographics were similar between the groups with the exception of age. The mean age was 70.1 years in the true positive group, 59.4 years in the true negative group, 65.1 years in the false positive group, and 64.1 years in the false negative group.

The authors defined CKD stage 1 as estimated glomerular filtration rate (eGFR)
≥90 ml/min/1.73 m² and albumin:creatinine ratio (ACR) ≥30 mg/g or proteinuria, stage 2 as eGFR between 60 and 89 ml/min/1.73 m² and ACR ≥30 mg/g or proteinuria, stage 3 as eGFR between 30 and 59 ml/min/1.73 m², stage 4 as eGFR between 15 and
29 ml/min/1.73 m², and stage 5 as eGFR <15 ml/min/1.73 m².

Of the patients in the study, 5036 had stage 1 to 5 CKD based on eGFR and albuminuria, but only 607 (12.1%) were identified as having CKD. The authors found that clinicians were more successful at diagnosing stage 3 to 5 CKD (21.6% accuracy) compared with stage 1 or 2 CKD (3.4% accuracy). They also said that patients in the true positive group tended to have more severe CKD compared with the false negative patients.

The researchers noted that only 4.3% of the 445 clinicians who enrolled ≥10 patients had a ≥50% likelihood of identifying CKD, while 48.8% of clinicians had a likelihood <50% and 47.0% did not identify any patients as having CKD.

Although most clinicians knew that low eGFR and proteinuria were associated with CKD, 51.4% of patients did not have a protein urine dipstick test, 52.9% did not have a urinary albumin-creatinine test, and 15.2% did not have an eGFR test performed.