Patterns of Care for Patients with Chronic Kidney Disease in the United States: Dying for Improvement

Hypertension Control.

Control of hypertension is viewed as a fundamental process of care for CKD and ESRD patients as this may attenuate the rate of progression of CKD to ESRD as well as reduce the risk of cardiovascular complications. Inadequate control of hypertension for the preponderance of hypertensive Americans has been repeatedly described (11). For example, the NHANES III survey demonstrated that 25%, 25%, and 15% of African Americans, Caucasians, and Mexican Americans, respectively, had BP controlled to the minimal acceptable range of <140/90. Similar levels of inadequate BP control were observed for patients with overt CKD (12). Twenty-seven percent and 11% of patients with CKD in NHANES III had BP <140/90 and 130/85, respectively. In cases where multiple antihypertensive medications are usually required to treat hypertension in the setting of end-organ damage, poor control is not surprising even among those patients treated for hypertension and kidney disease. These patients had a mean BP of 147/77 mmHg, and 48% were prescribed only a single antihypertensive medication. The small number of patients with adequate BP control should be viewed in the context of recommended values for BP control of ≤125/75 mmHg in CKD patients with proteinuria and ≤130/85 mmHg in patients without proteinuria (13). In addition to inadequate prescription of antihypertensive drugs, it appears that another confounder is the poor recognition of CKD. Despite the availability of widely disseminated clinical practice guidelines, recent audits of patient records show that implementation of these guidelines and even the simple recognition and/or communication of the presence of CKD is unsatisfactory (14,15⇓). Among age-eligible Medicare beneficiaries, only 12.5% of hypertensive and 7.8% of diabetic patients with ≥1+ dipstick proteinuria received comments on this overt abnormality at hospital discharge. Similar patterns were observed among patients with serum creatinine levels ≥2 mg/dl. Despite the evidence indicating the substantial risks associated with impairment of renal function, the clinicians failed to recognize CKD among hypertensive patients, including those with diabetes (14). Furthermore, misconceptions about screening tools to evaluate renal function contributed to underrecognition of CKD.

Treatment of Anemia.

Anemia management in CKD patients has been frequently scrutinized because it is an easily monitored care process. Moreover, by extrapolation from experiences in ESRD, treatment of anemia secondary to erythropoietin deficiency in CKD has been suggested to benefit CKD patients (16). Although there is far less direct evidence of benefit from anemia correction for CKD patients (10,17⇓) than for patients on dialysis (18–20⇓⇓), there is no direct evidence of harm associated with anemia treatment for these patients. Therefore, it is surprising that several recent surveys of incident Medicare-eligible ESRD patients observed severe anemia in the majority of patients (2,21⇓). Mean and median hematocrit values of 27.7% ± 5.9 and 27.8%, respectively, were reported. Although insurance coverage is available for the preponderance of CKD patients with anemia in the United States, only between 23% and 28% of these patients were prescribed epoetin alfa. There was minimal differentiation in this constrained prescription pattern for epoetin alfa by patient age, gender, or race. It is unclear why such limited adherence to clinical practice guidelines for anemia management in CKD exists, because there is a substantial improvement in anemia correction by 6 to 12 mo after RRT (2,22⇓; Alan Collins, personal communication 2001). For prevalent hemodialysis patients in the United States, the mean Hct and EPO dose increased from 1994 to 1998 from 31.1% (± 5.2) to 34.1% (± 3.7) and 58.2 U/kg (± 41.8) to 68.2 U/kg (± 55.0), respectively, and >90% of the patients were prescribed epoetin alfa.

Vascular Access Placement for Hemodialysis.

Like anemia management, widely distributed clinical practice guidelines for vascular access exist, offering advice for the timely placement and the preferred type of access for chronic use (23,24⇓). The National Kidney Foundation Kidney Disease Outcomes Quality Initiative Clinical Practice Guidelines on Vascular Access recommends that <10% of maintenance hemodialysis patients should be chronically dialyzed using percutaneous catheters, operationally defined as continuous catheter use for >90 d. A recent national survey of vascular access types among incident American hemodialysis patients found that 30%, 41%, and 29% were dialyzed through a catheter, prosthetic graft, and autologous fistula, respectively (25). Moreover, for prevalent hemodialysis patients, catheters were used in 22% of cases. There are several justifiable reasons for protracted dialysis catheter use; these include the catheter as a bridge angioaccess device while the patient is awaiting living-related kidney donor transplantation or maturation of an autologous fistula, or as a salvage device for patients with no other potential form of access. However, these rationales are relatively uncommon.

A likely major contributor to the low autologous fistula rate is inadequate patient preparation. This is supported by the observation that only approximately 36% of incident ESRD patients in the United States recall being told to protect their upper arm veins in anticipation of the formation of an internal vascular access (26). Late referral to a nephrologist is also associated with increased catheter use in the United States and likely reflects inadequate time for usable vascular access creation and maturation. In an analysis of the referral pattern of period prevalent hemodialysis patients in the northeastern United States, approximately 35% were observed to have their first nephrologist referral within 90 d of initiating RRT (27). Late-referred patients had a 45% increased risk of receiving dialysis through a percutaneous catheter (28). Last, in addition to the increased risk of luminal thrombosis, infection, unreliable blood flows, central venous stenosis, shorter use life, and patient cosmetic concerns, tunneled catheters are associated with a 39% increased risk of death (29).

Timing the Initiation of RRT and Modality Selection.

An intuitively critical component of the care of CKD patients is the timing of the initiation of RRT. Surprisingly, there is limited outcome data that support a preferred timing for the initiation of dialysis, whether this timing is based on symptoms, residual renal function, or GFR (10). However, based on pharmacokinetic assumptions about the minimum amount of solute clearance needed for patient survival in ESRD, a weekly Kt/V_r urea of 2.0 is equivalent to an unequilibrated Kt/V of 1.2 per hemodialysis session. This yields a renal urea clearance of 7 ml/min (normalized to V), renal creatinine clearance of 9 to 14 ml/min per 1.73 m², or a GFR of 10.5 ml/min per 1.73 m². Although the mean GFR of incident ESRD patients in the United States has increased from 7.2 to 9.5 ml/min per 1.73 m² from 1995 to 2000, most patients initiate dialysis at a level that may be associated with less than optimal outcomes (1,2⇓).

A corollary issue is the choice of RRT. In addition to the wide international variability in modality treatment selection (5), geographic variability exists within the United States. For example, <7 to >15% of the prevalent patients are treated by peritoneal dialysis across regions of the United States (2). The reasons for such variability are complex, but seem greatly influenced by conscious and subconscious physician biases. When patients are queried about modality choices for dialysis, 18% and 26% prefer hemodialysis and peritoneal dialysis, respectively. In contrast, 53% and 16% of patients are selected by physicians for hemodialysis and peritoneal dialysis, respectively (26). When a conjoined decision is made, 31% and 48% of patients are selected for hemodialysis and peritoneal dialysis, respectively. Another contributing factor is the timing of referral to the nephrologists. Contradictory information exists about the relationship between late nephrology referral and peritoneal dialysis selection. A contemporary analysis with sustained longitudinal follow-up failed to demonstrate a relationship between the timing of nephrologist input and the initial modality selection (30). However, patients who were referred late and initially treated by peritoneal dialysis were 50% more likely to switch to hemodialysis over the subsequent 6 mo. This modality switch is associated with a substantial increment in the costs of care.

Kidney transplantation is the preferred treatment for ESRD because of the improved patient survival, even in comparison to patients who are on a kidney transplant waiting list (31). For example, in comparison to patients on a waiting list, the relative risk of death is reduced to 0.32 by year 1 after successful kidney transplantation. Despite substantial survival and health-related quality of life benefits, most eligible transplant recipients in the United States have not been placed on a transplant waiting list 6 mo after beginning dialysis (32). In 2000, only 22% of dialysis patients <70 yr old were placed on a kidney transplant waiting list in the United States (2). The risk of late referral is greatest for African Americans and Native Americans. In addition to the choice of treatment modalities, timing is an important consideration. For example, a retrospective cohort analysis suggests that CKD patients who are transplanted before the start of dialysis have improved transplant survival as compared with those transplanted after receiving dialysis (33). Obviously, patients referred late for transplant evaluations cannot undergo preemptive kidney transplantation.

Rehabilitation and Preventive Health Services.

In view of the failure to address more critical components of care, it is not surprising that other important but less readily manageable components of CKD care, like patient rehabilitation, vocational, and preventive health services are all deficient in CKD patients in the United States. For example, most age- and health-eligible incident and prevalent patients with ESRD in the United States are unemployed. If vocational counseling and CKD education are offered to CKD patients with nonmanagerial jobs, the percent of patients that remain employed during ESRD doubles from 23% to 47% (34). Moreover, less than 40% of incident ESRD patients in the United States have received the recommended frequency of mammography, PAP examinations, and PSA or HbA1c measurements (35). Approximately one out of four diabetics with advanced CKD has had an eye exam, lipid profile, and HbA1c performed (2). Similarly, only 43% and 10% of ESRD patients received influenza and pneumococcal vaccinations, respectively, in the United States in 2000 (2).

Effect on ESRD Patient Survival.

It is imputed that these deficiencies in care for patients with advanced CKD adversely influence the survival of ESRD patients in the United States. Contemporary evidence supports this disturbing but intuitive contention (36,37⇓). For example, CKD patients referred to a nephrologist for the first time within 90 d of the start of dialysis have an approximately 40% to 60% increased risk of death during their first year of RRT. If fewer than five nephrology visits occur, death risks are increased 15%. Thirty-five percent of CKD patients are seen within 3 mo of receiving RRT. Late referral is more common among blacks than whites and was adversely influenced by the type of physician caring for the patient (37,38⇓). Thus, the need and opportunity to improve care for CKD patients clearly exists within the United States. Several legislative and regulatory initiatives are underway on a national level to eliminate fiscal and administrative barriers to appropriate CKD care. These initiatives are being supplemented by the development of clinical practice guidelines and performance measures to articulate best clinical practices and facilitate their monitoring.

“When there is a problem, he does not want to hear about it. When he hears, he does not listen. When he listens, he does not understand. When he understands, he does not follow-up. When he follows-up, it is always with half-measures.”

The penultimate intent is to disprove this contention; the ultimate intent is to improve ESRD outcomes by focusing on CKD processes of care.