Cross-sectional study, observation made by healthcare professionals of subjects or caregivers, administering romiplostim at their first standard-of-care visit 4 weeks after training with the home administration training pack. Further observations can also be recorded in the study if made within 16 weeks of enrolment. Data will be collected from the subjects' dose diary at their first standard of care visit to ensure there were no problems with administration while not at the clinic.

This cross-sectional study involves direct observation by a healthcare professional of a series of subjects and caregivers in the act of administering romiplostim at their first standard-of-care visit occurring 4 weeks after training with the HAT pack. Further observations, if they occur, will also be recorded in the study if made within 16 weeks of enrolment. (Additional observations are voluntary and are not required for study participation; they occur only if the healthcare professional requests them.) Additionally, data will be collected from the subjects' dose diary at the first standard of care visit to ensure there were no problems with administration while not at the clinic.

Inclusion Criteria:

• (1) adult ITP patient, treated per EU Summary of product characteristics (SmPC), or caregiver new (or at least a 3 month gap) to administering romiplostim,
• (2) has received HAT pack training,
• (3) available at standard-of-care medical visit 4 weeks (range 2 to 8 weeks) after HAT pack training,
• (4) patient provides informed consent.

Exclusion Criteria:

-No exclusion criteria for this observational study

ITP patients being treated with romiplostim will be approached for possible study participation. At each participating site, patients that meet the following criteria will be enrolled as a study subject. Adult ITP patients, treated per EU Summary of product characteristics (SmPC), or caregiver new (or at least a 3 month gap) to administering romiplostim, that has received HAT pack training and is available at a standard-of-care medical visit 4 weeks (range 2 to 8 weeks) after HAT pack training, the patient provides informed consent.