Translation and linguistic validation of the Pittsburgh Fatigability Scale for Korean breast cancer survivors: A cognitive interviewing study.

Background: Fatigability-the perception of fatigue contextualized to activities of fixed intensity and duration-has received growing attention in oncology research.

Objectives: This study aimed to translate and linguistically validate a Korean-language version of the Pittsburgh Fatigability Scale.

Methods: Following the Linguistic Validation Manual for Health Outcome Assessment, we applied a multi-stage cognitive interviewing (CI) method to ensure accurate translation and interpretation of the Pittsburgh Fatigability Scale. After forward- and backward-translation were completed, three rounds of CI regarding the translated instrument were performed with 18 participants having or not having breast cancer.

Results: The first round of CI showed that seven items of the 10-item Korean-language instrument required revision to reflect the physical abilities of breast cancer patients with similar levels of physical activity. After the second round, two additional items were revised to reflect the cultural context and gender roles. During the third round, all participants exhibited full understanding of the Korean-language instrument.

Conclusions: The translated instrument, its quality enriched by cross-cultural linguistic validation in combination with CI, can be effectively used to assess perceived physical and mental fatigability.

Implications for practice: Use of the Pittsburgh Fatigability Scale can facilitate oncology nurses' assessment of perceived fatigue levels in cancer patients and can expand understanding of how patients' fatigue perceptions are related to their exercise capacity.

Foundational: This study is valuable as an example of how a multi-stage CI process can be effectively applied in cross-cultural oncology research.