Comparison of SF-6D and EQ-5D Scores in Patients With Breast Cancer

Abstract

BackgroundUtility values are a key component of a cost-utility analysis. The EQ-5D and SF-6D are two commonly used measures for deriving utilities. Of particular importance is assessing the performance of these instruments in terms of validity.ObjectivesThis study aimed to compare the performance of the EQ-5D and the SF-6D in different states of breast cancer.Patients and MethodsThis was a cross-sectional study of 163 patients with breast cancer who attended the breast cancer subspecialty clinic affiliated with the breast cancer research center (BCRC) at ACECR, in Tehran, Iran, and were consecutively recruited. Patients completed several questionnaires, including the EQ-5D, SF-36, and general questions regarding their demographic characteristics. Utility values for different states of breast cancer were obtained using predetermined algorithms for the EQ-5D and SF-6D. The distribution of the utility values and the differences between the different states for both instruments were statistically assessed. Furthermore, the agreement between the two instruments was evaluated using intra-class correlation coefficients and Bland-Altman plots.ResultsThe mean and median EQ-5D utility scores for the total sample were 0.685 and 0.761, respectively. The mean SF-6D utility score for the total sample was 0.653, and the median utility score was 0.640. The mean utility values of the EQ-5D for “state P,” “state R,” “state S,” and “state M” were estimated as 0.674, 0.718, 0.730, and 0.552, respectively. The SF-6D provided mean utility values of 0.638, 0.677, 0.681, and 0.587 for those states. Both instruments assigned statistically significant (P < 0.01) scores for different states. The intra-class correlation for the two measures was 0.677 (95% confidence interval (CI): 0.558 - 0.764). The Bland-Altman plot indicated a better agreement on the higher values and that at higher values, the EQ-5D yields a higher score than the SF-6D; this relationship was reversed at lower values.ConclusionsAlthough the two instruments were able to discriminate between various states, the values derived from these instruments were quite different. This distinction could have influenced the conclusions of an economic evaluation. Further research is required to determine which instrument should be used in economic evaluations.

Economic and Humanistic Burden of Cervical Cancer in the United States: Results from a Nationally Representative Survey

“…29 Moreover, the change in SF-6D can also be underestimated because of a narrower range of utility scores (given that the SF-6D has a high lower boundary of 0.3), which can explain why no significant differences were detected in our sample. 27 Overall, the difference in EQ-5D and SF-6D found in our analysis is consistent with the prior studies and the EQ-5D may be a better instrument at detecting quality of life differences between these two groups.…”

“…One potential explanation for such a finding is the difference between EQ-5D and SF-6D instruments in measuring HRQoL. 27 The EQ-5D tend to generate higher utility scores when compared to the SF-6D. This is especially true in healthy population or patients with mild conditions/symptoms.…”

Once Bitten Twice Shy: Thinking Carefully Before Adopting the EQ-5D-5L

“…There are a wide range of preferencebased measures of quality of life tool available to the health economist, and an expanding range of alternative outcome measures based on concepts such as capabilities [24] or subjective well-being [25]. Many of these alternatives, notably the SF-6D, have a robust body of research spanning many years and supporting their use in a wide variety of patient groups [26][27][28][29][30][31]. This is something the EQ-5D-5L currently lacks and will only gain through time.…”

Health-related quality of life and disease burden of psoriasis in Iran

“…The other 10 studies used EQ-5D along with other kinds of methods or questionnaires, such as socio-demographic questionnaires, SF-36, TTO, VAS, DLQI, PASI, Type 2 Diabetes and Health Promotion Scale (T2DHPS). (Seyedifar et al, 2016, Karyani et al, 2016, Yousefi et al, 2016, Goudarzi et al, 2016, Assadi&Afshari, 2016, Javanbakht et al, 2015, Saffari et al, 2015, Hosseini Nejhad et al, 2013, Javanbakht et al, 2012 A cross-sectional analytical study was conducted by Karyani et al to measure HRQOL in Bthalassemia patients using ED-5D along with information about participants' demographic, socioeconomic, and health status was gathered. (Karyani et al, 2016) Another study also used ED-5D with information about participants' demographic in order to conduct their survey on patients with type 2 diabetes.…”

“…(Saffari et al, 2015) Six studies used Visual Analogue Scale (VAS) along with ED-5D including the paper we published. (Seyedifar et al, 2016, Goudarzi et al, 2016, Hosseini Nejhad et al, 2013, Javanbakht et al, 2012, Assadi&Afshari, 2016 (Yousefi et al, 2016) Another cross-sectional study, gathered data by using a socio-demographic questionnaire, EQ-5D, and SF-36 instruments on patients with β-thalassemia. (Javanbakht et al, 2015) Mean EQ-5D-3L index score in psoriasis patients was 0.62, which is lower than experienced by patients with type 2 diabetes (0.70), breast cancer (0.69) and beta thalassemia (0.86) patients In Iran (Table 32).…”