Trends in Prevalence of CKD Stages 3–5 in the Military Health System

Prevalence of Department of Defense Military Health System beneficiaries with eGFR <60 mL/min/1.73 m².

Source files from U.S. Department of Defense MHS Data Repository (MDR).

ICD Coding: GENESIS Encounter (BDE 3.0, direct care), GENESIS Admission Table (BDE 3.0, direct care), CAPER (direct care outpatient claims), SIDR (direct care inpatient claims), TED-NI (private care outpatient claims), TED-I Header (private care inpatient claims),

Laboratories: CDR Chemistry, SIDR, CADRE Laboratory Enhanced, GENESIS Laboratory Results (BDE 3.0), TED-NI (private-sector laboratory claims)

Demographics: VM6BEN (demographic information from the Defense Enrollment Eligibility Reporting System), GENESIS Person (BDE 3.0).

BDE: Bulk Data extract, CADRE: Comprehensive Ancillary Data Record Extract, CAPER: Comprehensive Ambulatory/Professional Encounter Record, CDR: Clinical Data Repository, GENESIS: name of the MHS EHR, SIDR: Standard Inpatient Data Record, TED-I: TRICARE Encounter Data – Institutional, TED-NI: TRICARE Encounter Data – Non-Institutional

Beneficiaries aged ≥ 18 years enrolled in the TRICARE Prime or Plus managed care options.

Fiscal years 2009−2023 (October 1, 2008, to September 30, 2023).

People with CKD stage 3−5 among the denominator population. Data cells with less than 11 counts were suppressed.

Population with an outpatient serum creatinine value available during the fiscal year. Adults with a diagnosis of dialysis or transplant were excluded. Data cells with less than 11 counts were suppressed.

CKD was defined by an average estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² over the fiscal year. Serum creatinine measured during inpatient encounters were excluded. Outlier values (serum creatinine ≤ 0 mg/dL or > 25 mg/dL, or eGFR > 200 ml/min/1.73 m²) were excluded. Beneficiaries with diagnosis of dialysis or transplant were excluded from eGFR categorization.

Based on the CKD-EPI (2021) equation for calibrated creatinine: eGFR=142 x [min(serum creatinine in mg/dL) /κ, 1)]**α x [max(serum creatinine/κ, 1)]**-1.20 x 0.9938**age x (1.012 if female).

κ = 0.7 if female and 0.9 if male
α = -0.241 if female and -0.302 if male
** = raise to the power

Laboratory measurements taken during outpatient encounters.

Dialysis (ICD-9): V45.1, V45.0, V56.1, V56.2, V56.3, V56.31, V56.32, V56.8, E879.1.

Dialysis (ICD-10): I95.3, R88.0, T81.502A, T81.502D, T81.502S, T81.512A, T81.512D, T81.512S, T81.522A, T81.522D, T81.522S, T81.532A, T81.532D, T81.532S, T81.592A, T81.592D, T81.592S, T82.41XA, T82.41XD, T82.41XS, T82.42XA, T82.42XD, T82.42XS, T82.43XA, T82.43XD, T82.43XS, T82.49XA, T82.49XD, T82.49XS, T85.611A, T85.611D, T85.611S, T85.621A, T85.621D, T85.621S, T85.631A, T85.631D, T85.631S, T85.691A, T85.691D, T85.691S, T85.71XA, T85.71XD, T85.71XS, Y62.2, Y84.1, Z49.01, Z49.02, Z49.31, Z49.32, Z91.151, Z91.158, Z91.A5, Z99.2.

Transplant (ICD-9): V42.0, 996.81.

Transplant (ICD-10): T86.10, T86.11, T86.12, T86.13, Z48.22, Z94.0.

Beneficiaries with ≥1 inpatient or ≥2 outpatient encounters with ICD-9 or ICD-10 codes for dialysis or transplant were excluded. During 2009–2023, 2.0%–3.9% of the CKD population was on dialysis and 2.3%–3.6% had received a kidney transplant.

Estimates were standardized to the 2010 U.S. Census population for adults: 18–39 years: 37.1%, 40–59 years: 38.1%, 60–69 years: 12.8%, and 70+ years: 12.0%.

The occurrence of CKD stages 1 and 2 cannot be calculated as results from urine albumin or urine protein testing are not included. In the MHS, each year approximately 50% of all adults do not have an outpatient serum creatinine measured, and another 15% have serum creatinine measured only in the private sector with unavailable results.

Reporting of race and ethnicity data has improved over time. In 2009, combined Unknown or Missing race and ethnicity was 28.4% of the total population with measured serum creatinine and 52.1% of the CKD stage 3–5 population. By 2023, Unknown or Missing race and ethnicity was 8.7% of the total population with measured creatinine and 10.4% of the CKD stage 3–5 population.

In published literature, CKD is defined by serum creatinine in alternate ways (single measurement, average of multiple measurements, persistence >90 days). Care must be taken in making comparisons. Our analysis used the average of measurements during the fiscal year in order to present data on a year-by-year basis. Active-duty service members constitute around 35% of TRICARE PRIME MHS beneficiaries and tend to be younger and healthier than the general population. Therefore, testing for serum creatinine may be performed less frequently than in other health care systems.

The contents of this publication are the sole responsibility of the authors and do not necessarily reflect the views, assertions, opinions or policies of the Uniformed Services University of the Health Sciences (USUHS), the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., the Departments of the Army, Navy, or Air Force, or the Department of Health and Human Services.