Aging underlies heterogeneity between comorbidity and multimorbidity frameworks

Area of Science:

• Geriatrics
• Internal Medicine
• Epidemiology

Background:

• Distinguishing between comorbidity and multimorbidity is crucial for understanding patient complexity.
• Multiple chronic conditions (MCC) are prevalent in hospitalized patients, necessitating clear definitions and impact assessments.

Purpose of the Study:

• To evaluate the prevalence of comorbidity and multimorbidity in an internal medicine ward.
• To compare these conditions with patient characteristics, including age, Cumulative Illness Rating Scale (CIRS) index, polytherapy, and mortality.
• To determine the independent predictors of in-hospital and 30-day mortality and readmission.

Main Methods:

• Single-center, observational study of 1394 consecutive internal medicine patients.
• Categorization of patients into no MCC, comorbidity, and multimorbidity groups.
• Statistical comparison with CIRS index, age, gender, polytherapy, 30-day readmission, and mortality data.

Main Results:

• 96.2% of patients had MCC; 20.5% had comorbidity, and 75.7% had multimorbidity.
• Both age and CIRS index increased significantly with the progression from comorbidity to multimorbidity (p < 0.001).
• Age was independently associated with in-hospital mortality, 30-day mortality, and 30-day readmission (p < 0.05), whereas comorbidity and multimorbidity were not.

Conclusions:

• Age is the most significant factor differentiating comorbid and multimorbid patients.
• Age independently predicts major adverse outcomes in a hospital setting, overshadowing the mere presence of multiple conditions.