Diffuse idiopathic skeletal hyperostosis in subjects with congestive heart failure undergoing cardiac rehabilitation: A decision tree analysis.

Objective: To assess the prevalence of diffuse idiopathic skeletal hyperostosis and its relationship with vascular risk factors among patients with congestive heart failure. Design: Population-based cross-sectional study. Participants: A total of 584 consecutive patients admitted to a Rehabilitative Cardiology Unit. Methods: Chi-square Automatic Interaction Detector (CHAID) decision tree analysis was used to build a predictive model. Results: The mean age (standard deviation) of the study population was 68.1 years (standard deviation 12.3), and 77.7% of the subjects were men. The overall prevalence of diffuse idiopathic skeletal hyperostosis in the cohort was 49.8%. Logistic regression analysis showed that age was a predictor of diffuse idiopathic skeletal hyperostosis (odds ratio 1.034; 95% confidence interval: 1.021-1.047, p< 0.001), with increasing odds ratios for increasing age tertiles. The CHAID prediction model identified 2 age "buckets": <= 569 and >69 years. Patients >69 years had a diffuse idiopathic skeletal hyperostosis prevalence of 60.1%, compared with 39.2% among those <= 69 years. Notably, body mass index was a predictor of diffuse idiopathic skeletal hyperostosis in this younger subset of patients (p= 0.028), with 2 body mass index buckets, <= 23.3 and > 23.3 kg / m(2), the latter showing more than twice the prevalence of diffuse idiopathic skeletal hyperostosis (43.2% vs 20%). Conclusion: Diffuse idiopathic skeletal hyperostosis is extremely frequent among patients with congestive heart failure, with age and body mass index being the strongest predictors.