Table 1 Overview of patients omitted from the study and the reasons for omission

Practical reasons (n = 133)

Lack of capacity to include (n = 90)

Patients admitted to the ICU in periods where there were no study investigators available to include or adequately follow up patients were omitted, for instance, during holiday periods.

Previous inclusion (n = 7)

Patients already included in the study who were readmitted to the ICU were omitted to avoid double inclusion.

Communication barriers (n = 18)

Foreign language patients or next of kin where consent could not be acquired due to communication barriers in spoken and/or written communication were omitted.

Too many without acute kidney injury already included (n = 18)

The protocol for the NORIDES study required two evenly distributed patient groups with and without acute kidney injury, some patients without acute kidney injury were omitted to achieve even numbers in the groups.

Medical reasons (n = 31)

Low or high patient weight (n = 11)

Patient weights were considered important for some of the outcomes of the study, patients below 50 kg or above 100 kg were therefore omitted as low or high patient weight were not exclusion criteria in the study protocol.

lasmapheresis treatment (n = 9)

Plasmapheresis treatment was considered important for some of the outcomes of the study; patients treated with plasmapheresis were therefore omitted from the study as it was not an exclusion criterion in the study protocol.

Hygienic reasons (n = 11)

The study involved an investigation with a Doppler ultrasound apparatus that could potentially transfer infectious diseases from one study participant to another; some patients were omitted to ensure infection prevention and control.

Legal or ethical reasons (n = 40)

Psychiatric conditions (n = 21)

Patients admitted to the ICU following suicide attempts were omitted as it was not an exclusion criterion in the study protocol. However, the study personal considered that inclusion could add potential strain for the participants.

End-of-life care (n = 19)

Study personal omitted patients who were not expected to survive at admission or had treatment withdrawal during ICU stay. Both circumstances were not exclusion criteria in the study protocol. However, the study personal considered that inclusion could add potential strain to the patients or next of kin.