Cohort Profile Update:The Haematological Malignancy Research Network (HMRN)’s UK population-based cohorts

Established in 2004, the Haematological Malignancy Research Network is an ongoing population-based UK cohort that is currently tracking 38 000 people diagnosed with a blood cancer or related disorder. Covering a population of ∼4 million people (14 hospitals), each year ∼2500 people enter the cohort (irrespective of age or prognosis) on the day they are diagnosed. All diagnoses are made and coded using the World Health Organization’s latest International Diseases for Oncology classification by haematopathologists at a single fully integrated laboratory. HMRN operates on a legal basis that permits all patients to be tracked through local clinical systems and linked to national administrative databases (hospital episode statistics, cancers and deaths). Patients diagnosed between 2009 and 2015 (n = 18 127) have now been matched (year of birth, sex and residency in the study area) to 10 randomly selected controls from the national population-based National Health Service Central Register. The pseudonymized comparison cohort described in this update was designed to facilitate analyses requiring general-population background rates on co-morbidities and healthcare activity.