Are our patients becoming more complex? Trends in comorbidity and functional dependence in General Medicine 2011-2019.

Background: Anecdotally, patients don't seem to be more unwell than they were 10 years ago, yet they still seem more 'complex'.

Aims: The aim of this study was to use an objective measure to assess the trend in complexity of general medicine patients over a 9-year period.

Methods: Complexity was pragmatically defined as a composite of comorbidity plus dependence/frailty. We selected 100 consecutive patients discharged from General Medicine at Monash Medical Centre (a tertiary hospital in Melbourne, Australia) in the month of April of each year from 2011 to 2019. For each patient, we retrospectively calculated their burden of comorbidity and their degree of dependency/frailty. Comorbidity was measured using the Charlson Comorbidity Index (CCI), and dependence/frailty was assessed using the Katz Index of Independence in Activities of Daily Living (Katz ADL) and the Braden Scale (BS). The BS is a pressure injury risk assessment tool. Additional demographic data were collected, including length of stay, admission and discharge residence, 30-day readmission rate and inpatient mortality.

Results: There was no statistically significant change in the CCI or the Katz ADL. The median BS did however significantly decrease from 19 in 2011 to 16 in 2019 (P = 0.006), reflecting an increased risk of pressure injuries.

Conclusions: Despite a stable level of comorbidity, our finding of a decreasing BS score may suggest that patients are becoming more dependent. This increase in dependency rather than a change in chronic disease burden may be the cause of apparent increasing patient complexity.