# Reliability of a German version of the Kansas City Cardiomyopathy Questionnaire (KCCQ) administered via telephone

## TL;DR

This study shows that a German version of the KCCQ can be reliably administered over the phone to assess quality of life in heart failure patients.

## Contribution

The study validates a telephone-administered German KCCQ for heart failure patients, filling a gap in telehealth tools.

## Key findings

- The German KCCQ via telephone showed good test-retest reliability for symptom and clinical scores.
- The overall summary score had an ICC of 0.83, indicating strong agreement between methods.
- The study supports using the telephone version to collect health status data in heart failure patients.

## Abstract

To date, there is no validated telephone version of the Kansas City Cardiomyopathy Questionnaire (KCCQ) available to collect data about health-related quality of life among patients with heart failure (HF). We assessed the reliability of the German KCCQ administered via telephone in comparison to the self-administered version. Patients with HF admitted to the outpatient clinic of the University Hospital Würzburg were consecutively identified and recruited. Patients completed (a) the self-administered version of the KCCQ, and (b) the telephone-based interview performed by trained raters. The sequence of both approaches was randomized. For the between-method agreement, the intraclass correlation coefficient (ICC) was calculated using a non-parametric, rank-based approach. We analysed data from sixty-one HF patients. The median KCCQ overall summary score was 84.8 (interquartile range (IQR) 71.6–76.9). The test-retest reliability between the self-administered and the telephone interview showed good agreement for the total symptom score, the clinical score and the overall summary core: ICC 0.75, 95 % confidence interval (CI) 0.72–0.79; ICC 0.80, CI 0.77–0.84; ICC 0.83, CI 0.80–0.86, respectively. The German KCCQ administered via telephone showed good test-retest reliability, indicating its applicability to collect data about health status among HF patients over the phone.

The online version contains supplementary material available at 10.1038/s41598-025-14179-6.