Figure 1.

Data flowchart.

Notes: Dataflow in The Danish National CLL Registry. At the time of diagnosis, baseline registration is performed at one of nine centers. Data are validated through cross-referencing with The National Patient Registry (NPR) and The Danish Cancer Registry (DCR). Data describing follow-up variables are continuously registered at the time of significant events. These data form the basis for quality assessment of treatment for patients with CLL in Denmark and offers a unique opportunity for population-based research.

Abbreviation: CLL, chronic lymphocytic leukemia.