Development and validation of ovarian symptom index-18 and neurotoxicity-4 for Korean patients with ovarian, fallopian tube, or primary peritoneal cancer

Purpose The purpose of this study was to develop Korean versions of the National Comprehensive Cancer Network/Functional Assessment of Cancer Therapy (NCCN-FACT) Ovarian Symptom Index-18 (NFOSI-18) and FACT/Gynecologic Oncology Group (FACT-GOG) Neurotoxicity 4-item (NTX-4), evaluating their reliability and reproducibility. Materials and Methods In converting NFOSI-18 and NTX-4, the following steps were performed: forward translation, backward translation, expert review, pretest of preliminary format, and finalization of Korean versions (K-NFOSI-18 and K-NTX-4). Patients were enrolled from six institutions where each had completed chemotherapy for ovarian, tubal, or peritoneal cancer at least 1 month earlier. In addition to demographics obtained by questionnaire, all subjects were assessed via K-NFOSI-18, K-NTX-4, and a Korean version of the EuroQoL-5 Dimension. Internal structural validity and reliability were evaluated using item internal consistency, item discriminant validity, and Cronbach's . To evaluate test-retest reliability, K-NFOSI-18 and K-NTX-4 were readministered after 7-21 days, and intraclass correlation coefficients (ICCs) were calculated. Results Of the 250 women enrolled during the 3-month recruitment period, 13 withdrew or did not respond, leaving 237 (94.8%) for the analyses. Mean patient age was 54.3±10.8 years. Re-testing was performed in 190 patients (80.2%). The total K-NFOSI-18 and K-NTX-4 scores were 49 (range, 20 to 72) and 9 (range, 0 to 16), respectively, with high reliability (Cronbach's =0.84 and 0.89, respectively) and reproducibility (ICC=0.77 and 0.84, respectively) achieved in retesting. Conclusion Both NFOSI-18 and NTX-4 were successfully developed in Korean with minimal modification. Each Korean version showed high internal consistency and reproducibility.