Real-World Patient-Reported Outcomes After Initiation of Adjuvant Ribociclib Plus Endocrine Therapy in Early HR+/HER2− Breast Cancer: A Multicentre Prospective Observational Study in Croatia (PRO-QoL-Cro)

Data sources

• Data source(s), other:
  Primary data collection at three participating centres in Croatia: patient-reported outcome questionnaires completed on paper by participants at study visits, and clinical data abstracted from routine hospital medical records. No pre-existing registry or database is used.
• Data sources (types):
  Electronic healthcare records (EHR)

  Patient surveys

Use of a Common Data Model (CDM)

• CDM mapping:
  No

Data quality specifications

• Check conformance:
  Yes
• Check completeness:
  Yes
• Check stability:
  Yes
• Check logical consistency:
  Yes

Data characterisation

• Data characterisation conducted:
  Yes
• Data characterisation moment:
  after creation of study variables
• Data characterisation details:
  Data are collected on paper source forms and entered into an EpiData database with predefined ranges and logical checks. Patient-reported outcome data are entered twice by independent operators and discrepancies are resolved against the paper source document, with corrections documented in a query log. Completeness of each questionnaire is checked at the study visit before the participant leaves the clinic, and the reason for any missing assessment is recorded in the case report form. Derived scores are recalculated independently and compared before the analysis dataset is locked.