IDF21-0404 Variations in comorbidity burden in patients with type 2 diabetes and impacts on healthcare resource usage and costs

Abstract

Background: The prevalence of type 2 diabetes (T2DM) is increasing, and cause of death and complications in this patient group are now much broader than the established macro and micro vascular complications. However, the extent and breadth of morbidity and how this varies across sub-groups is unclear. Aim: We aimed to estimate comorbidity profiles in patients with T2DM, variations across sub-groups and over the course of the disease, and associated healthcare resource use (HCRU) and health system costs. Method: We identified approximately 224,000 patients with T2DM in the Discover-NOW dataset, a real-world primary care database from 2000-2020 covering 2.5 million people across North West London, England, linked to hospital records. We generated a mixed prevalence and incidence study population through repeated annual cross sections, and included a broad set of 35 comorbidities covering traditional T2DM complications, emerging conditions and other common comorbidities. HCRU and costs across primary and secondary care included inpatient admissions, outpatient appointments and Emergency Department attendances. We estimated annual age-standardised prevalence of comorbidities, HCRU and costs over the course of the disease in patients with T2DM and several sub-groups, including by age, gender, and those with specific comorbidities at baseline. Results: Multimorbidity (two or more chronic conditions) is common in patients with T2DM and increasing, but the comorbidity profiles of patients with T2DM vary substantially. Nearly 30% of T2DM patients had three or more comorbidities at diagnosis, increasing to 60% of patients ten years later. Two of the five commonest comorbidities at diagnosis were expected (hypertension (37%) and ischaemic heart disease (10%)) the other three were not (depression (25%), back pain (15%) and osteoarthritis (11%)). The prevalence of each increased during the course of the disease, with more than one in three patients having back pain and one in four having depression ten years post diagnosis. Patients with five or more comorbidities at diagnosis had higher prevalence of each of the 35 comorbidities. Hypertension (73%) was the commonest comorbidity at diagnosis in this group; followed by back pain (69%), depression (67%), asthma (45%) and osteoarthritis (36%). Patients with obesity at diagnosis had substantially different comorbidity profiles to those without, and the five commonest comorbidities were 50% more common in this group. Between 2015 and 2019, the number of HCRU appointments per T2DM patient increased from 14.6 to 16.7. Annual costs increased from £1,300 to £2,100 over the same period. Inpatient admissions comprised 63% of total costs, the number of outpatient appointments increased over the study period, and other HCRU types remained stable. HCRU and costs were approximately 15-20% higher in women compared to men and over twice as high in adults >75 years (£2,900) compared to adults <55 years (£1,100). The largest differences were between patients with five or more comorbidities at diagnosis (29 HCRU events per year, £4,400) compared to those with two comorbidities or fewer (12 HCRU events, £700.) Discussion: Preventative and clinical measures alongside care pathways for patients with T2DM should transition to reflect the diverse set of causes driving persistent morbidity. This would benefit both patients and reduce increasing healthcare costs alike.