Abstract
Purpose:
Utilities are preference based quality of life (QoL) measures used in health economic evaluations such as cost-effectiveness studies. Utilities have been derived for a variety of ocular conditions but not previously reported for uncorrected refractive error (URE). This study evaluates utility associated with URE.
Methods:
This was a cross-sectional study involving participants presenting for an eye exam at a university based clinic. Participants met study criteria if aged 40-65 years, wore refractive error correction and had no ocular disease impairing vision worse than 0.1 LogMAR units in the better eye. All participants underwent a comprehensive eye examination including refraction, aided and unaided VA measures at 6m and 40cm using a Bailey-Lovie LogMAR chart. Utilities were elicited using the Time Trade-Off (TTO) method for a number of scenarios including the participants own corrected and uncorrected vision state. Utilities ranged from 0-1 where 0=death and 1=perfect vision and were scaled to account for co-morbidities so that 1= perfect health (adjusted utility).
Results:
Data analysis was based on a cohort of 341 participants (out of 361 screened). Unaided, 30 participants had no vision impairment, 65 had only distance vision impairment (DVI), 97 had only near vision impairment (NVI), 112 had moderate amounts of both distance and near vision impairment (DNVI) and 37 had severe impairment (distance or near impairment >1.0 LogMAR units) in the better eye. Unaided VA was DVI group 0.50±0.24 LogMAR at distance, NVI group 0.43±0.17 LogMAR at near, and DNI group 0.72±0.36 at distance and 0.56±0.29 at near. Adjusted utilities for the three groups were DVI 0.82±0.16, NVI 0.81±0.17 and DNVI 0.68±0.25. The (adjusted and unadjusted) DVI and NVI utilities did not significantly differ (p=0.73 and p=0.77 respectively). DNVI utility was significantly worse than DVI and NVI (adjusted and unadjusted p<0.01).
Conclusions:
URE is associated with measurable reductions in utility (and therefore QoL). Reductions are similar irrespective of whether near or distance vision is impaired but worse when both are impaired. The results underscore the significance of URE on QoL, particularly with respect to uncorrected presbyopia which has been a relatively neglected area in research and policy. The utility figures in this study can be used as inputs for cost-effectiveness evaluations for programs relating to URE to assist governments with resource allocation decisions.
Keywords: 460 clinical (human) or epidemiologic studies: health care delivery/economics/manpower •
669 quality of life •
754 visual acuity