Abstract
AIM—To ascertain utility values associated with varying degrees of legal blindness. METHODS—A cross sectional study on three group of patients. There were: (1) 15 patients with complete absence of vision (no light perception) in at least one eye who were asked to assume a scenario of no light perception in the second eye as well, (2) 17 patients with light perception to counting fingers in the better seeing eye, and (3) 33 patients with 20/200-20/400 vision in the better seeing eye. Utility values were measured using the time trade-off and standard gamble methods in each of the three groups. RESULTS—The mean time trade-off utility value for the no light perception group with the theoretical scenario of bilateral absence of light perception was 0.26 (95% CI, 0.19-0.33). The mean utility value for the light perception to counting fingers group was 0.47 (95% CI, 0.33-0.61), and the mean utility value for the 20/200-20/400 group was 0.65 (95% CI, 0.58-0.72). Thus, patients with no light perception in one eye, who were presented with the same scenario in the second eye as well, were willing to trade almost 3 out of every 4 years of remaining life in return for perfect vision in each eye. Those with light perception to counting fingers would trade approximately 1 of 2 remaining years and those with 20/200-20/400 would trade approximately 1 of 3 remaining years. CONCLUSIONS—There is a wide range of utility values associated with legal blindness. The utility value decreases dramatically with perceived total loss of vision (absence of light perception in each eye), compared with counting fingers to light perception vision, indicating that the preservation of even small amounts of vision in patients with legal blindness is critically important to their wellbeing and functioning in life.
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- Angell M. Patients' preferences in randomized clinical trials. N Engl J Med. 1984 May 24;310(21):1385–1387. doi: 10.1056/NEJM198405243102111. [DOI] [PubMed] [Google Scholar]
- Brown G. C., Brown M. M., Sharma S., Brown H. C. Patient perceptions of quality-of-life associated with bilateral visual loss. Int Ophthalmol. 1998;22(5):307–312. doi: 10.1023/a:1006311910304. [DOI] [PubMed] [Google Scholar]
- Brown G. C., Sharma S., Brown M. M., Garrett S. Evidence-based medicine and cost-effectiveness. J Health Care Finance. 1999 Winter;26(2):14–23. [PubMed] [Google Scholar]
- Brown M. M., Brown G. C., Sharma S., Garrett S. Evidence-based medicine, utilities, and quality of life. Curr Opin Ophthalmol. 1999 Jun;10(3):221–226. doi: 10.1097/00055735-199906000-00012. [DOI] [PubMed] [Google Scholar]
- Froberg D. G., Kane R. L. Methodology for measuring health-state preferences--II: Scaling methods. J Clin Epidemiol. 1989;42(5):459–471. doi: 10.1016/0895-4356(89)90136-4. [DOI] [PubMed] [Google Scholar]
- Kassirer J. P. Adding insult to injury. Usurping patients' prerogatives. N Engl J Med. 1983 Apr 14;308(15):898–901. doi: 10.1056/NEJM198304143081511. [DOI] [PubMed] [Google Scholar]
- Kassirer J. P. Incorporating patients' preferences into medical decisions. N Engl J Med. 1994 Jun 30;330(26):1895–1896. doi: 10.1056/NEJM199406303302611. [DOI] [PubMed] [Google Scholar]
- Lee T. T., Solomon N. A., Heidenreich P. A., Oehlert J., Garber A. M. Cost-effectiveness of screening for carotid stenosis in asymptomatic persons. Ann Intern Med. 1997 Mar 1;126(5):337–346. doi: 10.7326/0003-4819-126-5-199703010-00001. [DOI] [PubMed] [Google Scholar]
- Redelmeier D. A., Detsky A. S. A clinician's guide to utility measurement. Prim Care. 1995 Jun;22(2):271–280. [PubMed] [Google Scholar]
- Richardson J. Cost utility analysis: what should be measured? Soc Sci Med. 1994 Jul;39(1):7–21. doi: 10.1016/0277-9536(94)90162-7. [DOI] [PubMed] [Google Scholar]
- Sharma S. Levels of evidence and interventional ophthalmology. Can J Ophthalmol. 1997 Aug;32(5):359–362. [PubMed] [Google Scholar]
- Sonnenberg F. A., Beck J. R. Markov models in medical decision making: a practical guide. Med Decis Making. 1993 Oct-Dec;13(4):322–338. doi: 10.1177/0272989X9301300409. [DOI] [PubMed] [Google Scholar]
- Torrance G. W., Feeny D. Utilities and quality-adjusted life years. Int J Technol Assess Health Care. 1989;5(4):559–575. doi: 10.1017/s0266462300008461. [DOI] [PubMed] [Google Scholar]
- Wakker P., Stiggelbout A. Explaining distortions in utility elicitation through the rank-dependent model for risky choices. Med Decis Making. 1995 Apr-Jun;15(2):180–186. doi: 10.1177/0272989X9501500212. [DOI] [PubMed] [Google Scholar]
- Weinstein M. C., Stason W. B. Foundations of cost-effectiveness analysis for health and medical practices. N Engl J Med. 1977 Mar 31;296(13):716–721. doi: 10.1056/NEJM197703312961304. [DOI] [PubMed] [Google Scholar]