Objective: The aim of this retrospective study was to investigate the relationship between cancer, non-immunologic comorbidity, estimated by International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codification, gender and in-hospital mortality (IHM) in a large sample of renal transplant recipients (RTRs) living in the region Emilia-Romagna (RER) of Italy.
Patients and methods: We evaluated IHM in RTRs admitted between 2000 and 2013 recorded in the RER database. By using ICD-9-CM codes, the Elixhauser index (EI) was calculated, and cancers were identified and classified as skin cancers (SC), solid organ cancers (SOC) and post-transplant lymphoproliferative disorders (PTLD). IHM was the dependent variable of the multivariate models, while age, gender, EI corrected removing the effect of malignancies (cEI), and different types of cancer were the independent ones.
Results: During the examined period, a total of 9,063 admissions in 3,648 RTRs were recorded, of whom 117 died (3.2%). The mean age was 52.9±13.1 years. Cancers were reported in 580 admissions (6.4%), and mean cEI was 3.5±3.4. Deceased RTRs were older, had a higher prevalence of PTLD and SOC, and had a higher cEI than survivors. IHM was independently associated with (in decreasing order) PTLD (OR 12.431, 95%CI 5.834-26.489, p<0.001), SOC (OR 6.804, 95%CI 4.323-10.707, p<0.001), female gender (OR 1.633, 95%CI 1.057-2.523, p=0.006), cEI (OR 1.106, 95%CI 1.068-1.145, p<0.001), and age (OR 1.049, 95%CI 1.031-1.068, p<0.001) CONCLUSIONS: Cancer, in particular SOC and PTLD, is strongly associated with IHM in RTRs. On the other hand, rather surprisingly, female gender exhibited a stronger association with IHM than other more expected factors, such as comorbidity and age.