Hospital Discharge Records as Data Source to Monitor Epidemiologic Indicators of Hematologic Malignancies in Abruzzo

Purpose To test the feasibility of using hospital discharge records (HDR) to monitor frequency indicators of hematologic malignancies (HM) in Abruzzo, an Italian region without a cancer registry. Methods Hospital discharge records contain a primary diagnosis field for principal disease and 5 secondary diagnosis fields for other diseases related or not to the principal diagnosis. In order to build patient indicators of HM—non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), multiple myeloma (MM), and leukemia (acute lymphoblastic leukemia [ALL], chronic lymphoid leukemia [CLL], acute myeloid leukemia [AML], and chronic myeloid leukemia [CML])—residents with first ICD-9-CM code 200-208 in any HDR field, or only in primary field, were identified. Results Among 3,955 patients with first diagnosis of HM registered in primary or secondary fields of HDR in the 2009-2013 period, and never recognized in 2005-2008 (791/year) (60.5/100,000), patients with first HM only in primary field were 2,304 (461/year) (35.2/100,000): 42% were NHL, 34% leukemia, 16% MM, 8% HL. Patient percentage of 461/791/year (58%) (64% among ordinary HDR and 49% in day-hospital HDR) was 35% for CLL (28/81), 47% for MM (74/152), 50% for CML (16/32), 57% for HL (36/63), 62% for NHL (194/314), and 82% for ALL (18/22) and AML (64/78). Conclusions Applying the cancer registries national rate, expected new diagnoses of HM in Abruzzo are about 620/year (46.4/100,000), compared to HDR estimates of 461 and 791/year (primary/all diagnoses fields: 58%). Since this percentage varies between 35% and 82%, our findings on the 2 methods seem useful for a validation process in the starting Cancer Registry.