In this issue of Archives, the Submacular Surgery Trials Group presents an evaluation of the Vision Preference Value Scale (VPVS).1 In contrast to more commonly known measures of quality of life, such as the National Eye Institute Visual Function Questionnaire, which measures a person's perception of their visual function, the VPVS (and similar survey instruments, such as the Impact of Visual Impairment questionnaire2) measures a person's preference for function. That is, rather than asking if the person has difficulty reading, the investigator measures the person's preference for being able to read (ie, how much being able to read matters to the person). As with the National Eye Institute Visual Function Questionnaire, the investigator may use responses to the VPVS to create summary scales that measure the overall outcome of an intervention and thus the person's preference for the change in health status following treatment. In the Submacular Surgery Trials, Bass and colleagues have found that there was no difference in the change in preference for health state between the treatment and observation groups as measured by the VPVS. Given that previous reports from this group found that there was no significant difference in clinical outcomes between the groups,3,4 it is not clear whether this is being driven by the change in clinical status or the change in clinical status was not large enough to be perceived as elevating one's status to a more preferred health state.
Kymes SM. The Role of Preference-Based Measures of Health StatesHow Can We Use the Vision Preference Value Scale?. Arch Ophthalmol. 2008;126(12):1765-1766. doi:10.1001/archophthalmol.2008.525