Multimorbidity patterns in a primary care population aged 55 years and over.

Background: To support the management of multimorbid patients in primary care, evidence is needed on prevalent multimorbidity patterns.

Objective: To identify the common and distinctive multimorbidity patterns.

Methods: Clinical data of 120480 patients (≥55 years) were extracted from 158 general practices in 2002-11. Prevalence rates of multimorbidity were analyzed (overall, and for 24 chronic diseases), adjusted for practice, number of diseases and patients' registration period; differentiated between patients 55-69 and ≥70 years. To investigate multimorbidity patterns, prevalence ratios (prevalence rate index-disease group divided by that in the non-index-disease group) were calculated for patients with heart failure, diabetes mellitus, migraine or dementia.

Results: Multiple membership multilevel models showed that the overall adjusted multimorbidity rate was 86% in patients with ≥1 chronic condition, varying from 70% (migraine) to 98% (heart failure), 38% had ≥4 chronic diseases. In patients 55-69 years, 83% had multimorbidity. Numerous significant prevalence ratios were found for disease patterns in heart failure patients, ranging from 1.2 to 7.7, highest ratio for chronic obstructive pulmonary disease-cardiac dysrhythmia. For diabetes mellitus, dementia or migraine patients highest ratios were for heart failure-visual disorder (2.1), heart failure-depression (3.9) and depression-back/neck disorder (2.1), respectively (all P-values<0.001).

Conclusions: Multimorbidity management in general practice can be reinforced by knowledge on the clinical implications of the presence of the comprehensive disease patterns among the elderly patients, and those between 55 and 69 years. Guideline developers should be aware of the complexity of multimorbidity. As a consequence of this complexity, it is even more important to focus on what matters to a patient with multimorbidity in general practice.