Background: When evaluating health-economics for cervical cancer prevention policies in Japan, it is important to use Japanese value settings. This study aimed to obtain preference-based measures (preference measures) for hypothesized health states among healthy Japanese women, and to examine differences between the EuroQol-5D (EQ-5D) and standard gamble (SG) instruments.
Materials and methods: The investigation was performed among female students at a nursing university. We used written hypothetical scenarios describing three grades of cervical intraepithelial neoplasia (CIN) and eight stages of cervical cancer, both at diagnosis and after medical intervention. Preference measures were evaluated using both EQ-5D and SG.
Results: We received responses from 136 women. The mean number of respondents per stage was 24.6 (SD: 2.7). At diagnosis, average EQ-5D scores for CIN1, CIN2, CIN3, IA1, IA2, IB1, IB2, IIA, IIB, III, and IV stages were 0.84 (0.14), 0.78 (0.12), 0.73 (0.10), 0.78 (0.12), 0.72 (0.12), 0.63 (0.13), 0.64 (0.12), 0.68 (0.08), 0.62 (0.13), 0.55 (0.21), and 0.18 (0.24), respectively. Using one-way analysis of variance with the Tukey-Kramer method for multiple comparisons (each stage vs. CIN1), we found significant differences for IB1 and more advanced stages (p<0.05). After medical intervention, corresponding EQ-5D scores were 0.84 (0.12), 0.81 (0.12), 0.84 (0.12), 0.80 (0.15), 0.78 (0.11), 0.64 (0.15), 0.63 (0.15), 0.71 (0.15), 0.50 (0.17), 0.52 (0.17), 0.21 (0.28). The multiple comparisons identified significant differences for IB1 and more advanced stages, excepting IIA (p<0.05). SG evaluations were more variable and relatively higher than EQ-5D evaluations.
Conclusions: We obtained preference measures for three grades of CIN1-3 and eight stages of cervical cancer. In combination with appropriate sensitivity analyses, these preference measures will provide a basis for an economic evaluation of cervical cancer prevention in Japan. We suggest that EQ-5D is appropriate for cost-utility analysis of this topic.