Variation in Patients' Awareness of CKD according to How They Are Asked

Awareness of CKD is necessary for patient engagement and adherence to medical regimens. Having an accurate tool to assess awareness is important. Use of the National Health and Nutrition Examination Survey (NHANES) CKD awareness question "Have you ever been told by a doctor or other health professional that you had weak or failing kidneys (excluding kidney stones, bladder infections, or incontinence)?" produces surprisingly low measures of CKD awareness. We sought to compare the sensitivity and specificity of different questions ascertaining awareness of CKD and other health conditions.

Between August of 2011 and August of 2014, an in-person questionnaire was administered to 220 adults with CKD, diabetes, hypertension, or hyperlipidemia who received primary care in a public health care delivery system to ascertain awareness of each condition. CKD awareness was measured using the NHANES question, and other questions, asking if patients knew about their "kidney disease", "protein in the urine", "kidney problem", or "kidney damage." Demographic data were self-reported; health literacy was measured. The sensitivity and specificity of each question was calculated using the medical record as the gold standard.

In this diverse population (9.6% white, 40.6% black, 36.5% Hispanic, 12.3% Asian), the mean age was 58 years, 30% had a non-English language preference, and 45% had low health literacy. Eighty percent of participants had CKD, with a mean eGFR of 47.2 ml/min per 1.73 m(2). The sensitivities of each CKD awareness question were: 26.4% for "kidney damage", 27.7% for "kidney disease", 33.2% for "weak or failing kidneys", 39.8% for "protein in the urine", and 40.1% for "kidney problem." Specificities ranged from 82.2% to 97.6%. The best two-question combination yielded a sensitivity of 53.1% and a specificity of 83.3%. This was lower than awareness of hypertension (90.1%) or diabetes (91.8%).

CKD awareness is low compared with other chronic diseases regardless of how it is ascertained. Nevertheless, more sensitive questions to ascertain CKD awareness suggest current under-ascertainment.