Cross-Cultural Validation and Psychometric Testing of the Heart Failure Somatic Perception Scale in Japan

Background: The assessment of symptoms experienced by patients with heart failure (HF) has important contextual implications for self-care and allows for early recognition of signs of worsening HF. The Heart Failure Somatic Perception Scale (HFSPS) is a measurement tool developed in the U.S. to assess symptoms experienced by patients with HF, but it is expected to be applicable to patients in countries with different cultural backgrounds. Objectives: To evaluate the psychometric properties (validity and reliability) of the HFSPS in Japanese HF patients. Methods: This study assessed the factor structure of the HFSPS using confirmatory factor analysis in 320 HF outpatients in Japan. Criterion-related validity of the HFSPS was evaluated by correlating its factor scores with Patient-Reported Outcomes Measurement Information System (PROMIS) scores using Pearson's correlation coefficient. Internal consistency reliability of the HFSPS was evaluated using the factor score coefficient of determination, Cronbach's alpha, and the model-based internal consistency index. Results: The sample (n=320) was 72% male, mean age 72.9±12.8 years. Confirmatory factor analysis examining the four-factor structure of the HFSPS (dyspnea, chest discomfort, early and subtle, and edema), resulted in resulted in the following fit indices: χ2= (129, N=310), P<0.001, comparative fit index =0.825, Tucker-Lewis index =0.793, root mean square error of approximation =0.131. For criterion-related validity, all domains of the PROMIS items (physical health, mental health, global health, and social role satisfaction) were negatively correlated (-0.07 to -0.37) and statistically significant indicating higher symptom burden was associated with worse global health. HFSPS reliability resulted in Cronbach's alpha 0.878 for dyspnea, 0.607 for chest discomfort, 0.772 for early and subtle, 0.777 for edema, and 0.921 for the entire scale. Conclusion: This study suggests the HFSPS is a reliable and valid tool among Japanese with HF. Using this scale will provide accurate assessment of symptoms experienced by HF patients in research testing educational interventions to improve HF symptom recognition and response.