Comorbidity in an Older Population with Type-2 Diabetes Mellitus: Identification of the Characteristics and Healthcare Utilization of High-Cost Patients

Abstract

Objectives:Little is known about the specific comorbidities contributing to higher costs inpatients with type-2 diabetes mellitus (T2DM), particularly in older cases. We aimed to evaluatethe prevalence, type, and cost of comorbiditiesoccurringinolderT2DMpatientsversusoldernon-T2DM patients, and the factors associated with high cost (HC) T2DM patients.Methods:Retrospective cohort study using information from the Campania Regionhealthcare database. People aged≥65 years who received≥2 prescriptions forantidiabetic drugs were identified as“T2DM patients.”Comorbidities among T2DM andnon-T2DM groups were assessed through the RxRiskV Index (modified version). T2DMindividuals were classified according to the total cost distribution as HC or“non-high cost.”Two sub-cohorts of HC T2DM patients were assessed: above 90th and 80th percentile ofthe total cost. Age- and sex-adjusted logistic regression models were created.Results:Among the T2DM cohort, concordant and discordant comorbidities occurredsignificantly more frequently than in the non-T2DM cohort. Total mean annual cost perT2DM patient due to comorbidities was€7,627 versus€4,401 per non-T2DM patient.Among T2DM patients identified as being above 90th and 80th percentiles of costdistribution, the total annual costs were>€19,577 and>€2,563, respectively. Thehospitalization cost was higher for T2DM cases. Strongest predictors of being a HCT2DM patient were having≥5 comorbidities and renal impairment.Conclusion:HC patients accrued>80% of the total comorbidities cost in older T2DMpatients. Integrated care models, with holistic and patient-tailored foci, could achieve moreeffective T2DM care