General limitations were reported by a substantial percentage of the U.S. population. Even after age adjustment, prevalence of disability was higher in those with CKD. Those with CKD reported more limitations in their ability to work, in the type or amount work they could perform, in their ability to walk, and by confusion than those without CKD.
Similarly, the age-adjusted percentage of the U.S. population reporting at least some difficulty in performing activities was higher in those with CKD. One-quarter to one-third of those aged ≥65 years with CKD stage 3 or 4 reported difficulty in activities of daily living and leisure and social activities, and ≥60% reporting difficulties in lower extremity mobility and general physical activity.
Chart Explanation: Overall, during 1999-2014, age-adjusted percentages of reported limitations were high in the U.S. population. Of those aged ≥65 years, with CKD stage 3 or 4, 21.8%, 42.7%, 25.8%, and 16.3% reported limitations in the ability to work, in the type or amount of work performed, in walking, and by confusion, respectively. Additionally, even with adjustment for age, those in the older age group (≥65 years) reported 2- to 3-fold greater prevalence of limitations than those in the younger (20-64 years) group.
Age-adjusted rates of reported difficulties in performing activities were also generally high among U.S. adults, regardless of age. Specifically, among those aged ≥65 years with CKD of greater severity, limitations were reported more in activities of daily living (23.5%), instrumental activities of daily living (32.2%), leisure and social activities (25.3%), lower extremity mobility (63.7%), and general physical activity (61%) regardless of age. Many measures of disability remained associated with CKD status even after additional adjustment for comorbid conditions (obesity, diabetes, hypertension, cardiovascular disease, arthritis, and cancer) that could affect disability (not shown in figure).
The NHANES (National Health and Nutrition Examination Survey) is a nationally representative, cross-sectional survey that is currently conducted every 2 years by the National Center for Health Statistics to examine disease prevalence and trends over time in non-institutionalized U.S. civilian residents.
Although much information is available regarding disability among those with ESRD (USRDS, 2011), little has been reported regarding the burden of disability among those with earlier-stage CKD. The survey consists of a standardized in-home interview and a physical examination and blood and urine collection at a mobile examination center (MEC). Here we examined data from the 1999-2000, 2001-2002, 2003-2004, 2005-2006, 2007-2008, 2009-2010, 2011-2012, and 2013-2014 NHANES. Self-reported limitations in physical functioning were defined by answers of “yes” to questions such as “Does a physical, mental or emotional problem now keep you from working at a job or business?”; self-reported difficulties in activities were defined by answers of “some difficulty,” “much difficulty” or “unable to do” to items such as “How much difficulty do you now have getting in and out of bed?”
|Description of Measure||Prevalence of physical functioning limiations among those with CKD in the general population|
|Type of Data Source||Public|
|Health Care System Data||No|
|Regional or National?||National|
|Demographic Group||Non-institutionalized U.S. residents aged 20+ years|
|Numerator||Non-pregnant participants with completed physical functioning surveys and with CKD information who report having limitations|
|Denominator||Non-pregnant participants with completed physical functioning surveys and with CKD information|
|Definition of CKD||Presence of single albuminuria or eGFR<60 ml/min/1.73 m²|
|Glomerular filtration rate||Estimated using CKD-EPI equation for calibrated creatinine: eGFR=141 x [min(calibrated serum creatinine in mg/dL) /κ, 1)]α x [max(calibrated serum creatinine in mg/dL/κ, 1)]κ x 0.993age x (1.018 if female) x (1.159 if NH Black)|
κ = 0.7 if female, and 0.9 if male
α = -0.329 if female, and -0.411 if male
|Proteinuria||Urinary albumin-to-creatinine ratios of 30-299 mg/g (microalbuminuria) and >300 mg/g (macroalbuminuria); pregnant/menstruating women excluded|
|Primary Data Source Indicator||pfq.XXX variables|
|Primary Indicator Method of Measurement||Questionnaire (computer-assisted); ages 1+|
|Secondary (1) Variable||lbxscr: Serum creatinine, ages 12+|
|Secondary (1) Indicator Method of Measurement||Examination/Laboratory|
|Secondary (2) Variable||ridageyr: Age in years|
|Secondary (2) Indicator Method of Measurement||Questionnaire (interviewer-administered)|
|Secondary (3) Variable||ridgendr: Gender|
|Secondary (3) Indicator Method of Measurement||Questionnaire (interviewer-administered)|
|Secondary (4) Variable||raceth: Race/ethnicity|
|Secondary (4) Indicator Method of Measurement||Questionnaire (interviewer-administered)|
|Frequency of Measurement (Primary)||Once (cross-sectional)|
|U.S. Region Covered by Primary Variable||All|
|Period Currently Available||1999–2016|
|Additional Data Items of Interest||Stage of CKD|
|Limitations of Indicator||Self-reported, cross-sectional, missing data due to refusal; albuminuria single measurement|
|Analytic Considerations||Appropriate NHANES survey weights, including interview and MEC weights, must be used for all analyses; creatinine measurements must be calibrated for NHANES III, 1999-2000 and 2005-2006; many variable names differ across surveys; albuminuria must be adjusted over multiple years|
|Age Adjustment||Adjusted for the distribution of age within the sample.|
References and Sources:
National Institute of Diabetes and Digestive and Kidney Diseases. USRDS 2011 Annual Data Report: Atlas of Chronic Kidney Disease and End-Stage Renal Disease in the United States, Bethesda, MD: National Institutes of Health; 2011.