OBJECTIVES: This study aimed to evaluate the validity and reliability of HINT-8, a generic health-related quality of life (HRQOL) instrument, in breast cancer patients after surgery.

METHODS: Three hundred breast cancer patients who were admitted for surgery or who visited the outpatient clinic for postoperative follow-up at a tertiary hospital in South Korea were provided with self-administered HRQOL measurement instruments including HINT-8, EQ-5D-5L, EQ VAS, and FACT-B. Known group validity was assessed across a range of demographic features and clinical characteristics related to breast cancer. The discriminatory ability of the HINT-8 was determined by comparing mean scores of HRQOL instruments between groups with (mild/moderate/severe problems) and without problems (no problems), considering the level of severity of HINT-8 items. Construct validity was evaluated by Pearson correlation coefficients among the HINT-8 index and FACT-B subscales, respectively. Test-retest reliability was assessed by using Cohen’s kappa value and intra-class correlation coefficient (ICC).

RESULTS: HINT-8 index was lower in groups with older age, lower education, lower income, and comorbidities. Patients with no problems in each item of the HINT-8 showed significantly higher scores than subjects with problems in EQ-5D-5L index (p<0.01) and EQ VAS (p<0.01). In subjects without problems on the HINT-8, FACT-B subscale scores were also higher, as were FACT-G (general), FACT-Total, and trial outcome index. The Pearson correlation coefficients of HINT-8 index with EQ-5D-5L index and EQ VAS were 0.671 (p<0.01) and 0.577 (p<0.01), respectively. The correlation between the HINT-8 and the FACT-B subscales was highest in physical well-being (r=0.714, p<0.01) and lowest in social well-being (r=0.390, p<0.01). Kappa values of the HINT-8 ranged from 0.249 to 0.513; the ICC was 0.690 (CI 0.580, 0.780).

CONCLUSIONS: The HINT-8 appears to be valid to measure HRQOL in postoperative breast cancer patients.