Table 1

Study objectives

Primary objectivePrimary outcome
The proportion of eligible subjects agreeing to participate in the study—Recruitability
  • Proportion incident HD patients it is practical to approach, who prescreen as suitable for screening (eligibility for screening).

  • Proportion of screened patients who fulfil all eligibility criteria for participation in the study.

  • Proportion of these patients who agree to participate in the study.

The proportion of randomised subjects who remain in the study—RetainabilityProportion of patients randomised who remain in the study excluding study withdrawals, and reasons for withdrawals.
The proportion of subjects who adhere to protocol-driven changes in dialysis frequency—Protocol adherenceProportion of patients who adhere to protocol dialysis frequency.
The number of adverse and serious adverse events—Safety of the studyFrequency of hospital admission due to hyperkalaemia and fluid overload, and lower respiratory tract infection.
An estimate of the effectiveness of the intervention—Effect size
  • Dialysis dose and RKF as measured by Std Kt/V.

  • Rate of change (mean) of RKF in the first 6 and 12 months after randomisation.

Secondary objectivesSecondary outcome
Retention of RKFProportion of patients with interdialytic urea clearance ≥2 and ≥3 mL/min/1.73 m2 at 6 months.
Quality of life (QOL)QOL is assessed using EQ-5D-5L questionnaire.
Mood—depressionDepression assessed using PHQ-9 questionnaire.
Cognitive functionChange in cognitive function as assessed by MOCA tool.
Illness intrusivenessIllness intrusiveness is assessed using Illness Intrusiveness Rating Scale.
Functional status/frailtyFunctional status assessed by Clinical Frailty Score.
Vascular access failures or problemsFrequency of vascular access failures and interventions.
Major adverse cardiac events (MACE)MACE is assessed by recording of the frequency of the events.
SurvivalSurvival is measured by all-cause mortality.
  • EQ-5D-5L, EuroQol EQ-5D-5L questionnaire; HD, haemodialysis; MOCA, Montreal Cognitive assessment; PHQ-9, Patient Health Questionnaire, 9 question; RKF, residual kidney function; Std Kt/V, Standard Kt/V.