The prevalence of multimorbidity in primary care and its effect on health care utilization and cost

Objective. The aim of this observational study was to examine the prevalence and associated health care utilization and cost of patients with multimorbidity. Methods. All patients > 50 years of age were eligible for the study which took place in three primary care practices in the West of Ireland. Chronic medical conditions and associated health care utilization in primary and secondary care were identified through patient record review. Results. In a sample of 3309 patients in the community, the prevalence of multimorbidity was 66.2% (95% CI: 64.5-67.8) in those > 50 years of age. Health care utilization and cost was significantly increased among patients with multimorbidity (P < 0.001). After multivariate adjustment for age, gender and free medical care eligibility, the addition of each chronic condition led to an associated increase in primary care consultations (P = 0.001) (11.9 versus 3.7 for > 4 conditions versus 0 conditions); hospital out-patient visits (P = 0.001) (3.6 versus 0.6 for > 4 conditions versus 0 conditions); hospital admissions (P = 0.01) [adjusted odds ratio (OR) of 4.51 for > 4 conditions versus 0 conditions] and total health care costs (P < 0.001) (euro4,096.86 versus euro760.20 for > 4 conditions versus 0 conditions) over the previous 12 months. Conclusions. Multimorbidity is very common in primary care and in a system with strong gatekeeping is associated with high health care utilization and cost across the health care system. Interventions to address quality and cost associated with multimorbidity must focus on primary as well as secondary care