CDC Surveillance System: Antihypertensive Medication Use Among U.S. Adults

Footnotes:
^a There were significant differences in the age distribution of users versus nonusers. The difference in age distribution of users compared with nonusers has a p-value of <0.0001.

^b There were significant differences in the race distribution of users when compared with nonusers. The difference in race distribution of users compared with nonusers has a p-value of <0.0001.

^c There were significant differences in the distribution of users compared with nonusers across CKD stages. The difference in the distribution of users compared with nonusers across CKD stages has a p-value of <0.0001.

^d eGFR for this indicator was calculated using the isotope dilution mass spectrometry (IDMS)-traceable MDRD Study equation for calibrated creatinine. We are currently in the process of updating this indicator to instead use the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

There were significant differences in the age and race distribution of users versus nonusers in the examined CKD cohort. Participants aged 70 years or older represented the largest proportion of those using at least one antihypertensive medication, while the largest proportion of nonusers in the CKD cohort were those aged 40 to 59 years. Participants identifying as “other race/ethnicity” represented the smallest proportion of users, while the smallest proportion of nonusers comprises participants identifying as “black.” There were also significant differences in the distribution of users compared with nonusers across CKD stages. Stage 1 represented the highest proportion of nonusers, while stage 3 represented the highest proportion of users.

Chart Explanation: The baseline characteristics of users and nonusers of antihypertensive medication were compared in a CKD cohort. Users were defined as participants using at least one antihypertensive medication. 44.78% (n = 1873) of all participants with CKD reported using at least one antihypertensive medication. There were significant differences in the age and race distribution of users versus nonusers. Participants aged 70 years or older represented the largest proportion of those using at least one antihypertensive medication, while the largest proportion of nonusers in the CKD cohort were those aged 40 to 59 years. Participants identifying as “other race/ethnicity” represented the smallest proportion of users, while the smallest proportion of nonusers was comprises participants identifying as “black.” There were also significant differences in the distribution of users compared with nonusers across CKD stages. Stage 1 represented the highest proportion of nonusers, while stage 3 represented the highest proportion of users.

The NHANES is currently conducted every 2 years by the Centers for Disease Control and Prevention's National Center for Health Statistics to examine disease prevalence and trends over time in different cross-sectional representative samples of noninstitutionalized U.S. civilian residents. The survey consists of a standardized in-home interview and a physical examination and blood and urine collection at a mobile examination center (MEC). This study was a retrospective cross-sectional analysis of the NHANES surveys from 2005-2010. The study population comprises 116,231,361 NHANES participants aged 20 years and older with CKD. The investigators examined the antihypertensive medication use of the study population. eGFR was calculated according to the modified MDRD study formula for calibrated creatinine (Levey et al., 2005; Levey et al., 2006). Serum creatinine was calibrated for 2005-2006 participants; no correction was required for calibrated serum creatinine in participants in the 2007-2008 and 2009-2010 surveys (Selvin et al., 2007). Albuminuria was defined by urinary albumin-to-creatinine ratios of 30-299 mg/g (microalbuminuria) and >300 mg/g (macroalbuminuria); pregnant women were excluded.

This indicator is based upon analysis in published literature: Sonawane KB, Qian J, Hansen RA. Utilization patterns of antihypertensive drugs among the chronic kidney disease population in the United States: a cross-sectional analysis of the national health nutrition examination survey. Clin Ther. 2015;37(1):188-196.
http://www.ncbi.nlm.nih.gov/pubmed/25524390

Field	Data
Description of Measure	Proportion of users and nonusers of antihypertensive medication in the CKD population
Data Source	NCHS/CDC
Type of Data Source	Public
Data Set	NHANES
Health Care System Data	No
Regional or National?	National
Demographic Group	Noninstitutionalized U.S. residents aged 20+ years
Numerator	Users of antihypertensive medication among NHANES participants aged 20 years or older with CKD; nonusers of antihypertensive medication among NHANES participants aged 20 years and older with CKD
Denominator	NHANES participants aged 20 years or older with CKD
Definition of CKD	eGFR ≥ 90 ml/min/1.73 m² and estimated persistent albuminuria; eGFR 60-89 ml/min/1.73 m² and estimated persistent albuminuria; Stage 3, eGFR 30-59 ml/min/1.73 m²; Stage 4, 15-29 ml/min/1.73 m²; Stage 5, excluded
Glomerular filtration rate	Estimated using MDRD study formula for calibrated creatinine: eGFR=175 × [(calibrated serum creatinine in mg/dl)-1.154] × age-0.203 × (0.742 if female) × (1.210 if African-American) Schwartz formula for 12- to 17-year-olds: eGFR=k × (height in cm) × (serum creatinine in mg/dl), where k=0.55 for 1-13-year-olds and females 13-17; and k=0.65 for males 13-17
Proteinuria	Spot urine albumin-to-creatininewas used from the laboratory data for assessment of kidney damage (417 mg/g for men or 425 mg/g for women indicates kidney damage at stages I and II), and this information was subsequently used to identify the early stages of CKD
Primary Data Source	Antihypertensive medication utilization
Primary Indicator Method of Measurement	Questionnaire component of NHANES; participants were asked if they had taken a medication in the past month for which a prescription was required and respondents who answered “yes” were asked to provide the drug container to obtain names of the drugs
Frequency of Measurement (Primary)	Once (cross-sectional)
Period Currently Available	2005–2010
Pending Data	None
U.S. Region Covered by Variable	All
Additional Data Items of Interest	Age, sex, race, self-reported hypertension, self-reported diabetes
Limitations of Indicator	Data on use of antihypertensive medication might be inaccurate due to the data collection method used (i.e., interviews)
Analytical Considerations	Appropriate NHANES survey weights must be used for all analyses; creatinine measurements must be calibrated for 2005-2006; many variable names differ across surveys; if standard error 30% or more of estimate, must report as “low precision”

References and Sources:

Sonawane KB, Qian J, Hansen RA. Utilization patterns of antihypertensive drugs among the chronic kidney disease population in the United States: a cross-sectional analysis of the national health nutrition examination survey. Clin Ther. 2015;37(1):188-196.
http://www.ncbi.nlm.nih.gov/pubmed/25524390

Suggested Citation:

Centers for Disease Control and Prevention. Chronic Kidney Disease Surveillance System—United States.
website. http://www.cdc.gov/ckd