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

PEG Epoetin Beta Dose From the Start of the Observation Period Until the Switch

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.

Time frame: Month -3, Month -2, Month -1

Darbepoetin Alfa Dose From the Switch Date 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.

Time frame: Month 1, 2, 3, 4, 5 and 6

Dose Ratio Measured at the Time of Switch From PEG Epoetin Beta to Darbepoetin Alfa

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).

Time frame: Week -1 and Week 1

Hemoglobin Concentration Rate of Change by Period

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.