Abstract
Purpose: :
To determine if the disutilities related to the consequences of impaired vision obtained from a community based sample differ significantly to that from people with impaired vision and if the degree of vision impairment is related to the time willing to be traded.
Methods: :
180 participants with impaired vision were recruited from hospital clinics and rehabilitation agencies. Three levels of impairment were sampled: those with mild (<20/20–20/60); moderate (<20/60–20/200) and severe (<20/200) impairment. A stratified (by socio–economic status) sampled control group of 184 non–impaired cases from the Melbourne metropolitan area was included. A 6–item multi–dimensional vision–specific questionnaire, the VisQoL was administered. Additionally, disutilities were obtained from mean time–trade–off (TTO) values from the total of the VisQoL items.
Results: :
The community–based sample was significantly younger than the vision impaired (VI) group (there was no significant difference within the VI cohort by strata). Analysis controlled for age between the community and VI groups. As predicted, people with VI rated their vision–related quality of life as poorer than those from the community on the VisQoL total (16.9 vs 9.0, F=344.9, p<0.001). Consistent with this, the visually impaired were willing to trade more time for their own perfect health (0.21 vs 0.06 years, F=38.3, p <0.001). When the value of impairment was examined, however, there was no significant difference in TTO weighting (disutility) between the VI and community groups (0.87 vs 0.86, p>0.05). There was also no significant difference in the TTO weightings for those with mild (0.87), moderate (0.83) and severe vision impairment (0.89), p >0.05.
Conclusions: :
While each group rated their own health significantly differently, concern about the consequences of vision impairment is equally shared by those with impaired vision and people from the community.
Keywords: low vision • quality of life