Table 1

Utility by BCVA in treated eye

Health state defined by BCVA category (letters; treated eye)RESTORE*Lloyd et al12 Brown et al13 §
Mean utility (SE)
1: 86–1000.860 (0.034)0.8300.839
2: 76–850.860 (0.014)0.7500.839
3: 66–750.813 (0.012)0.7500.783
4: 56–650.802 (0.014)0.7150.783
5: 46–550.770 (0.018)0.6800.732
6: 36–450.760 (0.027)0.6800.681
7: 26–350.681 (0.053)0.5300.630
8: 0–250.547 (0.083)0.3400.579
  • * Utility scores were calculated based on EQ-5D scores in RESTORE; EQ-5D scores were converted to utilities using social tariffs measured in a UK population.14 Mean utility for each BCVA state was calculated using a regression technique for repeated measurements at baseline, month 3, month 6 and month 12. Data from several measurement points were pooled to cover all possible health state transitions with a sufficient sample size. A possible trend effect in the pooled data was rejected (p<0.05).

  • Patients underwent a Snellen visual acuity (VA) assessment and were categorised based on the better-seeing eye. Some adjustments were made to published values in order to convert VA ranges in Lloyd et al (obtained in a population of patients with diabetic retinopathy) to health states as defined in the current model.

  • § Utilities were elicited from patients with diabetic retinopathy. Patients underwent a Snellen VA assessment and were categorised based on the better-seeing eye. Some adjustments were made to published values in order to convert VA ranges to health states as defined in the current model.

  • Restricted to being greater than or equal to the utility in health state 2.

  • BCVA, best corrected visual acuity.