Can you provide information about the Initiating Dialysis Early and Late (IDEAL) trial?

The IDEAL Trial: Key Information for Clinical Practice

The IDEAL (Initiating Dialysis Early and Late) trial was a landmark randomized controlled trial conducted in Australia and New Zealand that definitively showed no survival benefit or improvement in clinical outcomes from starting dialysis early (eGFR 10-14 mL/min/1.73 m²) versus late (eGFR 5-7 mL/min/1.73 m²), fundamentally changing the approach to dialysis initiation timing. 1, 2

Trial Design and Population

The IDEAL study randomized 828 adult patients across 32 centers between July 2000 and November 2008. Patients had:

• Progressive chronic kidney disease with creatinine clearance 10-15 mL/min/1.73 m²
• Mean age of 60.4 years
• 355 patients (43%) with diabetes
• Notably healthier than typical dialysis populations (only 6% had congestive heart failure versus one-third in routine U.S. practice)
• Extensive pre-existing nephrology care 1, 2

Patients were randomized to:

• Early-start group (n=404): Target eGFR 10-14 mL/min/1.73 m²
• Late-start group (n=424): Target eGFR 5-7 mL/min/1.73 m² 1, 2

What Actually Happened

The trial faced significant crossover challenges:

• 19% of early-start patients started later than planned
• 76% of late-start patients started earlier than planned (primarily due to uremic symptoms)
• Actual mean creatinine clearance at dialysis initiation: 12.0 mL/min (early) vs 9.8 mL/min (late)
• Actual mean eGFR at initiation: 9.0 vs 7.8 mL/min/1.73 m²
• Median time difference to dialysis initiation: only 5.6 months 1, 2

Primary Outcomes: No Difference

During median follow-up of 3.59 years:

• Mortality: 37.6% (early-start) vs 36.6% (late-start); hazard ratio 1.04 (95% CI 0.83-1.30, p=0.75)
• No significant differences in:
  • Cardiovascular events
  • Infectious events
  • Dialysis complications
  • Cardiac structure or function (substudy)
  • Healthcare costs (trend toward higher costs with early start, but not significant) 1, 2

Modality-Specific Findings

Peritoneal Dialysis Subgroup (56% of participants, n=466)

Results remained consistent with no mortality benefit (HR 1.04,95% CI 0.79-1.37). However:

• Early-start patients were more likely to actually initiate with PD: 80% vs 70% (p=0.01)
• No difference in peritonitis rates: 0.73 vs 0.69 episodes per patient-year 3

Hemodialysis Subgroup (44% of participants, n=362)

• No mortality difference (HR 0.97,95% CI 0.66-1.41, p=0.86)
• Late-start group had significantly more fluid and electrolyte events (p=0.02)
• No difference in cardiovascular events, infections, or access-related complications 4

Critical Clinical Implications

The KDOQI 2015 guidelines, informed primarily by IDEAL, concluded that there is no compelling evidence that initiating dialysis based solely on kidney function measurement improves clinical outcomes, including mortality. 1

Key Practice Changes:

1. Do not start dialysis based on eGFR or serum creatinine alone in asymptomatic patients
2. Focus on uremic symptoms as the primary driver for dialysis initiation
3. Be aware that serum creatinine-based eGFR is misleading in elderly patients and those with low muscle mass (overestimates true GFR) 1

Important Caveats:

• IDEAL participants were healthier than typical dialysis populations, limiting generalizability
• The targeted separation in kidney function was not achieved due to symptom-driven early starts in the late group
• IDEAL contrasts with observational studies that suggested harm with early initiation—no such harm signal appeared in this randomized trial 1

Real-World Impact

A registry-based follow-up study demonstrated substantial clinical impact:

• Before IDEAL (2000-2010): Mean eGFR at dialysis start increased 0.21 mL/min/1.73 m²/year
• After IDEAL (2010-2018): No temporal change in eGFR at dialysis start (-0.01 mL/min/1.73 m²/year)
• Economic impact: Return on investment of AU$35.70 per AU$1 spent on the trial
• Estimated savings: Up to AU$84 million/year to Australian and New Zealand health systems 5

When to Actually Start Dialysis

Based on IDEAL and KDOQI guidelines, initiate dialysis when patients develop:

• Uremic symptoms (nausea, vomiting, altered mental status, pericarditis, bleeding)
• Protein-energy malnutrition despite optimization attempts
• Fluid overload unresponsive to medical management
• Severe metabolic derangements (hyperkalemia, metabolic acidosis) refractory to conservative management
• Inability to control blood pressure or volume status 1

Do not use a specific eGFR threshold as the sole criterion for dialysis initiation. In otherwise asymptomatic patients with advanced CKD, direct efforts toward preparing for seamless transition to kidney replacement therapy rather than rushing to start dialysis. 1