TRANSFORM - Observational Cohort Study of Darbepoetin Alfa Use in European Union (EU) Hemodialysis Patients Switched From PEG Epoetin Beta

Hemoglobin concentration from 3 months prior to switch to darbepoetin alfa until the end of the observation period.

Mean weekly doses were calculated per participant by first calculating a mean daily dose for the interval (by dividing each dose evenly between the days bounded by its date of administration and the day before the next dose, then taking a mean of these partial doses for the days in the interval) and multiplying by 7 to convert to a weekly dose. Weekly doses >150 μg have been excluded as they were deemed infeasible values derived by the algorithm.

Mean weekly doses were calculated per participant by first calculating a mean daily dose for the interval (by dividing each dose evenly between the days bounded by its date of administration and the day before the next dose, then taking a mean of these partial doses for the days in the interval) and multiplying by 7 to convert to a weekly dose. Weekly doses >150 μg have been excluded as they were deemed infeasible values derived by the algorithm.

Dose ratio is the average weekly dose of the first darbepoetin alfa dose divided by the average weekly dose of peg-epoetin beta at switch (μg darbepoetin alfa per 1 μg pegylated-epoetin beta).

The hemoglobin rate of change is the maximum monthly increase and maximum monthly decrease for the pre- and post-switch periods. Within each period, the difference was calculated between each hemoglobin value and the most recent hemoglobin value taken at least 28 days previously. The rate of change was calculated by dividing this difference by the number of days in the interval and multiplying by 28. The maximum and minimum rate of change was then determined per participant.

The percentage of participants with at least one hemoglobin excursion, defined as hemoglobin concentrations below 10.0 g/dL and above 12.0 g/dL during the pre- and post-switch periods.