Simple Model to Predict Chronic Kidney Disease

Released: 24-Feb-2007 9:05 AM EST
Embargo expired: 26-Feb-2007 12:00 AM EST
Source Newsroom: NewYork-Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College
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Citations Archives of Internal Medicine (26-Feb-2007)

Chronic kidney disease (CKD), a serious and progressive medical condition, has been and remains under-identified. While it is easy and inexpensive to test for kidney function, people who are at high risk for CKD are not routinely screened. To better identify those at increased risk for potentially undiagnosed CKD, a team of public health and medical researchers from Weill Cornell Medical College and the University of North Carolina (UNC) at Chapel Hill performed the first study of its kind to develop a tool to identify patients who are most at risk for CKD. (The simple questionnaire is available below.)

"Kidney disease often occurs in conjunction with a number of other conditions, including diabetes and high blood pressure, but many patients and their family members are not aware of this association," says Dr. Heejung Bang, assistant professor in the Division of Biostatistics and Epidemiology in the Department of Public Health at Weill Cornell Medical College.

Dr. Bang is the primary author of the study, which is published in today's Archives of Internal Medicine.

Patients with CKD can be identified early by a test that measures the level of creatinine in the blood. (Serum creatinine, a breakdown product of muscle, is elevated in people with impaired kidney function.) They can then be given treatments that will significantly delay the progression to end-stage kidney disease. Early detection and treatment of CKD can also lessen cardiovascular complications that sometimes occur with the condition.

"Unfortunately, many patients do not find out they have CKD until it has progressed to end-stage kidney disease," says Dr. Abhijit V. Kshirsagar, of the Kidney Center and Division of Nephrology, University of North Carolina School of Medicine, the senior author and major medical investigator of the research project. "The purpose of the study was to determine which patient characteristics are most associated with CKD, and to develop a simple method to identify individuals who should be screened in a variety of different settings in real life."

The researchers examined comprehensive demographic, clinical and medical history variables as potential risk factors of CKD, based on the medical literature on this subject. Through statistical modeling and validation, they were able to determine that only seven factors -- age, female gender, hypertension, diabetes, cardiovascular disease, proteinuria (an abnormal amount of protein in the urine) and anemia -- had significant associations with CKD in the study group. These characteristics are easily identified by the general public and health-care providers through a user-friendly questionnaire. They frequently occur together and cumulatively affect underlying kidney disease.

If a patient completes the questionnaire with a total score of four or higher, a confirmatory testing for creatinine concentration and/or glomerular filtration rate (GFR), directed by a health-care professional, would be strongly recommended. Thirty-six percent of the 8,530 study participants scored four or higher on the questionnaire.

"Although current clinical practice guidelines recommend screening of individuals 18 years or older with a family history of diabetes, hypertension or kidney disease, or a personal history of diabetes or hypertension, these recommendations focus on single risk factors and do not quantify the cumulative effect of multiple risk factors. Our method made use of the coexisting risk factors that were identified by a valid scientific approach, greatly enhanced upon the concept-based selection, and rigorously followed the practice of evidence-based research," said Dr. Bang.

In the future, the questionnaire will be tested in several settings, including a community-based screening program. The researchers hope their model will be used not only in medical encounters such as in primary care or nephrology clinics, but also in public health initiatives and education programs. The scoring algorithm will be posted on medical information Web sites for public use, including the UNC Kidney Center Web site, to make people more familiar with associated risk factors and to increase awareness of this serious disease.

The co-authors of the study were Drs. Suma Vupputuri and David A. Shoham, epidemiologists from UNC; and Drs. Philip J. Klemmer, Debbie Gipson and Romulo E. Colindres, from the Kidney Center and Division of Nephrology, School of Medicine, at UNC. The two mentoring co-authors were Drs. Ronald J. Falk of UNC and Dr. Madhu Mazumdar, chief of the Division of Biostatistics and Epidemiology in the Department of Public Health at Weill Cornell Medical College.

Get scored on your risk for chronic kidney disease! Find out if you might have silent chronic kidney disease now. Check each statement that is true for you. If a statement is not true or you are not sure, put a zero. Then add up all the points for a total.

Age:
-I am between 50 and 59 years of age.
if yes, score 2: ______

-I am between 60 and 69 years of age.
if yes, score 3: ______

-I am 70 years old or older.
if yes, score 4: ______

I am a woman.
if yes, score 1: ______

I had/have anemia.
if yes, score 1: ______

I have high blood pressure.
if yes, score 1: ______

I am diabetic.
if yes, score 1; ______

I have a history of heart attack or stroke.
if yes, score 1: ______

I have a history of congestive heart failure or heart failure.
if yes, score 1: ______

I have circulation disease in my legs.
if yes, score 1: ______

I have protein in my urine.
if yes, score 1: ______

Total ______

If you scored four or more points, you have a one in five chance of having chronic kidney disease. At your next doctor's visit, a simple blood test should be checked. Only a professional health-care provider can determine for sure if you have kidney disease. If you scored between zero and three points, you probably do not have kidney disease now, but at least once a year, you should take this survey.

For more information, patients may call (866) 697-6397.

Weill Cornell Medical College

Weill Cornell Medical College -- located in New York City -- is committed to excellence in research, teaching, patient care and the advancement of the art and science of medicine. Weill Cornell, which is a principal academic affiliate of NewYork-Presbyterian Hospital, offers an innovative curriculum that integrates the teaching of basic and clinical sciences, problem-based learning, office-based preceptorships, and primary care and doctoring courses. Physicians and scientists of Weill Cornell Medical College are engaged in cutting-edge research in such areas as stem cells, genetics and gene therapy, geriatrics, neuroscience, structural biology, cardiovascular medicine, AIDS, obesity, cancer and psychiatry -- and continue to delve ever deeper into the molecular basis of disease in an effort to unlock the mysteries behind the human body and the malfunctions that result in serious medical disorders. Weill Cornell Medical College is the birthplace of many medical advances -- from the development of the Pap test for cervical cancer to the synthesis of penicillin, the first successful embryo-biopsy pregnancy and birth in the U.S., and most recently, the world's first clinical trial for gene therapy for Parkinson's disease. Weill Cornell's Physician Organization includes 650 clinical faculty, who provide the highest quality of care to their patients.


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