A Study to Assess Change in Functioning and Health Related Quality of Life in Adult Participants With Chronic Lymphocytic Leukemia (CLL) Receiving Oral Treatments in Routine Clinical Practice in Spain

Inclusion Criteria: * Have documented chronic lymphocytic leukemia (CLL) according to International Workshop on Chronic Lymphocytic Leukemia (iwCLL) criteria. * Under oral treatment for CLL, either first-line or relapsed/refractory (R/R) therapy. * Treatment for CLL started 9 months (+/- 4 weeks) before inclusion for first-line therapy or 21 months (+/- 4 weeks) before inclusion for R/R, under authorized conditions. * In the opinion of the investigator, cognitive ability to understand and answer the questionnaires specified in the study protocol. * Able to comply with the study protocol in the investigator's judgment. Exclusion Criteria: * Currently receiving any chemotherapy or chemoimmunotherapy. * Transformation of CLL to aggressive non-Hodgkin's lymphoma (NHL) (Richter's transformation or pro-lymphocytic leukaemia). * Currently participating in interventional research (not including non-interventional study, post-marketing observational study, or registry participation). * Any serious medical condition or abnormality in clinical laboratory tests that, in the investigator's judgment, precludes the participant's safe participation in and completion of the study.