Determinants of Health Preferences Using Data from the Egyptian EQ-5D-5L Valuation Study

Urban/rural differences in preferences for EQ-5D-5L health states: a study of a multi-ethnic region in China

OBJECTIVES

This study aimed to compare health preferences for EQ-5D-5L health states between urban and rural populations in China.

METHODS

This study used pooled secondary data from two EQ-5D-5L valuation studies. Participants were recruited from Guizhou province and Chongqing municipality, China using quota sampling. Each participant was interviewed face-to-face to value a set of 15 or 16 out of 30 EQ-5D-5L health states using time trade-off (TTO) methods including composite TTO and other two variants. Regression analysis was used to compare health state preferences between urban and rural participants.

RESULTS

A total of 597 participants (urban: 55.44%; rural: 44.56%) completed the valuation interviews. Both univariate and multivariable linear regression analyses showed that rural participants tended to value health states lower than urban participants regardless of severity of health states. The unadjusted and adjusted overall mean differences between the two groups were - 0.041 (95% confidence interval [CI] - 0.077, - 0.004, p-value = 0.031) and - 0.040 (95% CI - 0.078, - 0.002, p-value = 0.038), respectively. Predictions for the 3125 health states based on rural participants' health preferences were lower than those based on urban participants' health preferences.

CONCLUSION

There were small, yet statistically significant, differences in EQ-5D-5L health states preferences between urban and rural populations in China. Future study aiming at establishing a national value set should pay more attention to the sample representativeness.

The Egyptian EQ-5D-5L Extensive Pilot Study: Lessons Learned

OBJECTIVES

To investigate the effect of an extensive pilot phase in improving protocol compliance, face validity, reduction of interviewer effect and prediction errors in the composite time trade-off (cTTO) data elicited as part of the EQ-5D-5L valuation study in Egypt.

METHODS

This study used the cTTO data and quality control (QC) reports from the Egyptian EQ-5D-5L valuation study. Three-level mixed models were estimated to test whether interviewer effects were reduced during the pilot phase and subsequent rounds of collected cTTO data. Ordinary least square (OLS) regression analysis was conducted for each interviewer separately to test whether the mean absolute error (MAE) improved as interviewers completed more interviews. Moreover, improvement in protocol compliance, face validity and reduction of prediction errors in the cTTO data were tested.

RESULTS

1180 interviews were conducted by nine interviewers and included in the final analysis, of which 206 interviews were pilot and 974 interviews were actual. There was substantial improvement in the face validity and reduction of prediction errors in the cTTO data where the MAE of the actual data was 0.37, which is much lower than that of the pilot data, which was 0.44. However, there was an initial high level of protocol compliance in terms of the four indicators of the QC tool and the variance attributed to the interviewers was small throughout the whole study.

CONCLUSIONS

This study clarified the benefits of the pilot phase and the strict implementation of the QC tool in improving the face validity and the prediction accuracy of the cTTO data. However, a more extensive pilot phase may be more beneficial in EQ-5D-5L valuation studies that have issues initially with protocol compliance and interviewer effects.

Do they just know more, or do they also have different preferences? An exploratory analysis of the effects of self-reporting serious health problems on health state valuation

BACKGROUND

Health state valuation is often conducted by people valuing either only their own health state (experience-based valuation) or several stylised states (hypothetical valuation). The approach used can affect the elicited values, but it is not clear whether this is caused by different understandings of the states (an "information mechanism") and/or by different opinions of the states (a "preference mechanism"). Justifying privileging the valuations of those with the relevant health state experience solely because they are better informed is insufficient when their opinions differ. This study proposes a new framework to examine the effect of having health problems on health state valuation by distinguishing "within-dimensional" effects (which can be due to better information or due to differences in opinion) and "cross-dimensional" effects (which must be due to differences in opinion).

METHODS

Secondary data from the UK that valued EQ-5D-5L using Discrete Choice Experiments with duration (DCE_TTO) are remodelled controlling for whether a respondent self-reports serious (viz., severe or extreme) problems in "pain or discomfort" (PD) or "anxiety or depression" (AD). The main analysis uses respondents who have serious PD or serious AD alongside matched respondents who do not, and assumes constant proportional time trade-off.

RESULTS

Self-reporting serious PD or serious AD problems has no within-dimensional effect on health state preferences. However, self-reporting serious AD problems has negative cross-dimensional effects on the utility of having any problem in PD, which suggests that the preference mechanism is present. A similar pattern holds when all available (unmatched) data are used and when constant proportional time trade-off is relaxed.

CONCLUSIONS

Findings consistent with the preference mechanism indicate that those with serious health problems may have different opinions on the value of health states compared to the rest of the population, which has normative implications for the debate on which values to use.