Patient population and data collection
pneumonitis, death, lung abnormality, infection, haemorrhage
PNEUMONITIS, LUNG INFLAMMATION, VENO-OCCLUSIVE DISEASE, DISEASE, AML, INFECTION, HAEMORRHAGE, SECONDARY, BONE MARROW FIBROSIS, LEUKAEMIA
A selection of baseline patient characteristics was made to investigate the effect of these prognostic factors on different CODs before start of chemotherapy. We obtained the following baseline variables: date of birth, gender, WHO performance status, AML or MDS, white blood cell (WBC) count at diagnosis, prior haematological or oncological disease, previous chemotherapy or radiotherapy, bone marrow cellularity, bone marrow fibrosis. Time dependent variables included outcome (death/alive), COD and occurrence of IA.From the infection form the variable ‘occurrence of IA’ was created by identification of all patients with an occurrence of IA at any time point in the treatment schedule. Cases in which the diagnosis of IA was uncertain (n = 72) were discussed by two investigators (MdB and RvG) and final decision was based on consensus (17 IA; 55 no IA). In case consensus would not be reached, a third expert was consulted (MvdB). In most cases that were discussed only treatment with an antifungal agent was registered without mention of IA. That was not considered enough evidence for diagnosis IA. The uncertain cases that were classified as IA had a lung abnormality on imaging and were treated with an antifungal agent. The timepoint of IA was estimated from the chemotherapy cycle date in which the occurrence of IA was registered. Diagnosis of IA was made by the treating physician at the time. The data did not contain information about clinical characteristics, which diagnostic test was performed for the diagnosis of IA, or certainty of diagnosis according to EORTC/MSGERC guidelines [In the dataset the COD was grouped into the following categories: leukaemia (including high-risk MDS), pneumonitis, infection, haemorrhage, veno-occlusive disease, secondary malignancy, other COD or unknown. Cause of death was recorded according to the clinical judgement of the treating physician at the time of death, as the rate of autopsy in this patient population was very low. In most patients the COD was described in a free text field as well. By checking the description of the COD, a few misclassified COD were reclassified.For modelling purposes different CODs were grouped together. The variables ‘infection’ and ‘other COD’ were grouped together (‘infection and other COD’), because ‘other COD’ included 12/70 patients with infection as one of the documented CODs as well. In total, 158/216 (73%) in the group ‘infection and other COD’ had an infection. The variables ‘pneumonitis’, ‘haemorrhage’, ‘veno-occlusive disease’, ‘secondary malignancy’ and ‘unknown’ were grouped together as ‘miscellaneous’. In haematology patients pneumonitis is mostly defined as lung inflammation induced by chemotherapy. Therefore pneumonitis was not considered an infection.