Norton Scale Score and long-term healthcare services utilization after acute myocardial infarction

Many patients admitted with acute myocardial infarction (AMI) have considerable multimorbidity, sometimes associated with functional limitations. The Norton Scale Score (NSS) evaluates clinical aspects of well-being and predicts numerous clinical outcomes. We evaluated the association between NSS and long-term healthcare utilization (HU) following a non-fatal AMI.

A retrospective observational study including AMI survivors during 1 January 2004 to 31 December 2015 with a filled NSS report. Data were recouped from the electronic medical records of the hospital and two Health Maintenance Organizations. Norton Scale Score ≤16 or >16 was defined as low or high respectively. The outcome was annual HU, encompassing length of hospital stay (LOS), emergency department (ED) visits, primary care, and other ambulatory service utilization during up to 10 years of follow-up. HU costs were compared between groups. Two-level models were built: unadjusted and adjusted for patients' baseline characteristics. The study included 4613 patients, 784 (17%) had low NSS. Patients with low NSS compared with patients with high NSS were older, had a higher rate of multimorbidity, and had significantly lower coronary angiography and revascularization rates. In addition, low NSS patients presented higher annual HU costs (4879 vs. 3634 Euro, P <0.001), primarily due to LOS, ED visits, and less frequent ambulatory services usage.

In patients after non-fatal AMI, low NSS is a signal for higher long-term costs reflecting the presence of expensive comorbidities. Management disparity and impaired mobility may offset the real need of these patients. Therefore, the specific proactive nursing intervention in that population is recommended.