Abstract 2091: Cluster Analysis of Elderly Cardiac Patients Based on Prehospital Symptomatology
Aim Using cluster analysis (STATA, 9.0), we examined how elderly patients with acute ischemic heart disease (IHD) clustered based on their presenting symptoms in the week before a cardiac event. We determined if these clustered patient groups varied based on general physical and mental health (SF-36), mood disturbance (POMS) and quality of life (QOL-I). Multiple concurrent symptom experience may have more synergistic effect on quality of life and psychological distress than an individual symptom. However, the majority of research has focused on examining the effects of individual symptoms.
Methods A sample of 247 elderly, unpartnered, patients (age ≥ 65) who were admitted with IHD to one of five University medical centers were inducted into a clinical trial (R01 NR005205); we are reporting on baseline data only. Patient interviews were used to assess cardiac symptoms, medical history, SF-36, POMS and QOL-I. Patients were clustered using squared Euclidean distances and average weighted linkages. Since cluster analysis has not fit indices, the appropriate cluster solution was determined using a combination of dendograms, stopping rules (Duda/Hart and Calinski) and clinical judgment of researchers. To examine characteristics of patients, ANOVA and Chi Square were used.
Results Three clusters (groups) were identified:
22%: Classic symptoms (severe ischemic pain),
29%: Weary (severe fatigue, sleep disturbance and shortness of breath),
49%: Diffuse symptoms (mild symptomatology).
Post hoc test revealed that the Weary group was significantly younger, more likely to have a history of heart failure and more likely to have CABG, but there were no differences for gender or co-morbidities. The Weary group had significantly lower scores on all SF-36 subscales (p<.01) except for the physical functioning and health transition subscales, on QOL-I (p<.001) and higher POMS scores (p<.01), compared to the Diffuse symptom group.
Conclusion The cluster analysis based on multiple concurrent cardiac symptoms was useful to identify the subgroup with the lowest levels of general physical and mental health, quality of life and the most mood disturbance. The Weary group needs more attention and interventions to improve their physical and psychological functioning.