Cluster analysis of elderly cardiac patients' prehospital symptomatology.

BACKGROUND: Chest pain routinely brings patients into the healthcare system, and elderly patients may present with more complex symptoms presaging ischemic heart changes than do younger patients.
OBJECTIVE: To examine, using cluster analysis, how elderly patients experiencing an ischemic coronary heart disease cluster based on presenting symptoms in the week before hospitalization and how they vary in terms of their general physical and mental health, mood states, and quality of life.
METHODS: Elderly (age >or=65 years), unpartnered patients (N = 247) admitted with ischemic coronary heart disease to one of five university medical centers were inducted into a clinical trial; only baseline data are reported. Interviews assessed cardiac symptoms, medical history, general physical and mental health, mood states, and quality of life. Patients were clustered (grouped) using squared Euclidean distances and weighted average linkage. Characteristics of patients were examined using analysis of variance and chi-squared analyses.
RESULTS: Three clusters (groups) were identified: (a) Classic Acute Coronary Syndrome (severe ischemic pain; 22%), (b) Weary (severe fatigue, sleep disturbance, and shortness of breath; 29%), and (c) Diffuse Symptoms (mild symptomatology; 49%). Post hoc tests revealed that the Weary group was more likely to have a history of heart failure; they also exhibited significantly more psychological distress and lower quality of life than the other subgroups.
CONCLUSION: Cluster analysis proved useful in grouping patients based on their symptom experience, but further research is needed to clarify the relationships among identified symptoms, psychological distress, and health outcomes; develop interventions for Weary patients; and extend the findings of this study.