THE DEPLETION OF SUSCEPTIBLES EFFECT IN THE ASSESSMENT OF BURDEN-OF- ILLNESS: THE EXAMPLE OF AGE -RELATED MACULAR DEGENERATION IN THE COMMUNITY- DWELLING ELDERLY POPULATION OF QUEBEC
Main Article Content
Keywords
Macular degeneration, burden-of-illness, elderly, depletion of susceptibles
Abstract
Background
With the aging of the population, age-related macular degeneration (AMD) is becoming a public health concern. Few studies have assessed its consequences on morbidity and mortality, and the findings are conflicting.
Objectives
To assess the risk of depression, fracture, institutionalization, and death among elderly patients with suspected exudative AMD and the impact of the depletion of susceptibles effect in a burden-of-illness study.
Methods
A population-based retrospective cohort study was conducted in the community-dwelling elderly population of Quebec. The cohort was assembled through the Quebec medical claims database (RAMQ). Among patients age 65 and older with a claim involving a diagnosis of AMD over the years 2000 to 2004, those with suspected exudative AMD (n=2,071) were retained, using fluorescein angiography as a marker. The reference cohort consisted of a sample of 16,932 elderly without a claim involving AMD or visual impairment.
Results
Suspected exudative AMD was associated with an increased risk of depression (hazard ratio HR=1.3, 95%CI 1.18-1.43) and fracture (HR=1.19, 95%CI 1.03-1.37), but a decreased risk of institutionalization (HR=0.55, 95%CI 0.42-0.71) and death (HR=0.68, 95%CI 0.59 -0.78). After adjustment for the incident/prevalent status of the AMD, the association between suspected exudative AMD and institutionalization was no longer statistically significant (HR=0.75, 95%CI 0.5-1.12) .
Conclusions
These findings enhance the need to detect visual loss and to consider patients’ ability to adapt to AMD, to maintain their quality of life. Failure to account for duration of illness and the depletion of susceptibles effect may bias results of burden-of-illness studies.
References
2. Ke KM, Chakravarthy U, O'Neill C. Economic cost of age-related macular degeneration: a review of recent research. Drugs Aging 2006;23:217-25.
3. Schmier JK, Jones ML, Halpern MT. The burden of age- related macular degeneration. Pharmacoeconomics 2006;24:319-34.
4. Hopley C, Carter R, Mitchell P. Measurement of the economic impact of visual impairment from age- related macular degeneration in Australia. Clin Experiment Ophthalmol 2003;31:522-9.
5. Tasman W, Rovner B. Age-related macular degeneration: treating the whole patient. Can J Ophthalmol 2005;40:389-91.
6. Tasman W, Rovner B. Age-related macular degeneration: treating the whole patient. Arch Ophthalmol 2004;122:648-9.
7. Fine SL, Berger JW, Maguire MG, Ho AC.Age-related macular degeneration. N Engl J Med 2000;342:483-92.
8. Taylor HR, Keeffe JE, Vu HT, et al. Vision loss in Australia. Med J Aust 2005;182:565- 8.
9. West S, Sommer A. Prevention of blindness and priorities for the future. Bull World Health Organ 2001;79:244-8.
10. Berman K, Brodaty H. Psychosocial effects of age-related macular degeneration. Int Psychogeriatr 2006:1- 14.
11. Casten RJ, Rovner BW, Tasman W. Age-related macular degeneration and depression: a review of recent research. Curr Opin Ophthalmol 2004;15:181-3.
12. Klein R, Klein BE, Linton KL. Prevalence of age-related maculopathy. The Beaver Dam Eye Study. Ophthalmology 1992;99:933- 43.
13. Kelliher C, Kenny D, O'Brien C. Trends in blind registration in the adult population of theRepublic of Ireland 1996- 2003. Br J Ophthalmol 2006;90:367-71.
14. Lee PP, Feldman ZW, Ostermann J, Brown DS, Sloan FA. Longitudinal prevalence of major eye diseases. Arch Ophthalmol 2003;121:1303-10.
15. Nowak JZ. Age-related macular degeneration (AMD): pathogenesis and therapy. Pharmacol Rep 2006;58:353-63.
16. Slakter JS, Stur M. Quality of life in patients with age- related macular degeneration: impact of the condition and benefits of treatment. Surv Ophthalmol 2005;50:263-73.
17. Park W. Vision rehabilitation for age-related macular degeneration. Int Ophthalmol Clin 1999;39:143-62.
18. Rovner BW, Casten RJ. Activity loss and depression in age- related macular degeneration. Am J Geriatr Psychiatry 2002;10:305-10.
19. Rovner BW, Casten RJ, Tasman WS. Effect of depression on vision function in age-related macular degeneration. Arch Ophthalmol 2002;120:1041-4.
20. Brody BL, Gamst AC, Williams RA, et al. Depression, visual acuity, comorbidity, and disability associated with age-related macular degeneration. Ophthalmology 2001;108:1893-900; discussion 1900- 1.
21. Rovner BW, Casten RJ. Neuroticism predicts depression and disability in age-related macular degeneration. J Am Geriatr Soc 2001;49:1097-100.
22. Scott IU, Schein OD, Feuer WJ, Folstein MF, Bandeen-Roche K. Emotional Distress in Patients With Retinal Disease. Am J Ophthalmol 2001;131:584-589.
23. Williams RA, Brody BL, Thomas RG, Kaplan RM, Brown SI. The psychosocial impact of macular degeneration. Arch Ophthalmol 1998;116:514-20.
24. Meads C, Hyde C. What is the cost of blindness? Br J Ophthalmol 2003;87:1201- 4.
25. Klein BE, Moss SE, Klein R, Lee KE, Cruickshanks KJ. Associations of visual function with physical outcomes and limitations 5 years later in an older population: the Beaver Dam Eye Study. Ophthalmology 2003;110:644-50.
26. Klein BE, Klein R, Lee KE, Cruickshanks KJ.Performance-based and self- assessed measures of visual function as related to history of falls, hip fractures, and measured gait time. The Beaver Dam Eye Study. Ophthalmology. 1998;105:160-4.
27. Ivers RQ, Cumming RG, Mitchell P, Attebo K. Visual impairment and falls in older adults: the Blue Mountains Eye Study. J Am Geriatr Soc 1998;46:58-64.
28. Freeman EE, Egleston BL, West SK, Bandeen- Roche K, Rubin G. Visual acuity change and mortality in older adults.Invest Ophthalmol Vis Sci 2005;46:4040- 5.
29. Thiagarajan M, Evans JR, Smeeth L, Wormald RP, Fletcher AE. Cause-specific visual impairment and mortality: results from a population-based study of older people in the United Kingdom. Arch Ophthalmol 2005;123:1397-403.
30. Cacciatore F, Abete P, Maggi S, et al. Disability and 6-year mortality in elderly population. Role of visual impairment. Aging Clin Exp Res 2004;16:382-8.
31. Borger PH, van Leeuwen R, Hulsman CA, et al. Is there a direct association between age- related eye diseases and mortality? The Rotterdam Study. Ophthalmology 2003;110:1292-6.
32. Klein R, Klein BE, Moss SE. Age-related eye disease and survival. The Beaver Dam Eye Study. Arch Ophthalmol 1995;113:333-9.
33. Voutilainen-Kaunisto RM, Terasvirta ME, Uusitupa MI, Niskanen LK. Age-related macular degeneration in newly diagnosed type 2 diabetic patients and control subjects: a 10- year follow-up on evolution, risk factors, and prognostic significance. Diabetes Care 2000;23:1672-8.
34. Buch H, Vinding T, la Cour M, Jensen GB, Prause JU, Nielsen NV. Age-related maculopathy: a risk indicator for poorer survival in women: the Copenhagen City Eye Study. Ophthalmology 2005;112:305- 12.
35. Clemons TE, Kurinij N, Sperduto RD. Associations of mortality with ocular disorders and an intervention of high-dose antioxidants and zinc in the Age -Related Eye Disease Study: AREDS Report No. 13. Arch Ophthalmol 2004;122:716-26.
36. VonKorff M, Wagner EH, Saunders K. A chronic disease score from automated pharmacy data. J Clin Epidemiol. 1992;45:197-203.
37. Suissa S. Inhaled steroids and mortality in COPD: bias from unaccounted immortal time. Eur Respir J. 2004;23:391-5.
38. Jackson ML. Vision rehabilitation for Canadians with less than 20/40 acuity: the SmartSight model. Can J Ophthalmol 2006;41:355-61.
39. Taylor HR. Eye care for the future: the Weisenfeld lecture. Invest Ophthalmol Vis Sci 2003;44:1413-8.
40. Cox A, Blaikie A, MacEwen CJ, et al. Visual impairment in elderly patients with hip fracture: causes and associations. Eye 2005;19:652-6.
41. Ivers RQ, Norton R, Cumming RG, Butler M, Campbell AJ. Visual impairment and risk of hip fracture. Am J Epidemiol 2000;152:633-9.
42. Ivers RQ, Cumming RG, Mitchell P, Simpson JM, Peduto AJ. Visual risk factors for hip fracture in older people. J Am Geriatr Soc 2003;51:356-63.
43. Felson DT, Anderson JJ, Hannan MT, Milton RC, Wilson PW, Kiel DP. Impaired vision and hip fracture. The Framingham Study. J Am Geriatr Soc 1989;37:495-500.
44. Cox A, Blaikie A, Macewen CJ, et al. Optometric and ophthalmic contact in elderly hip fracture patients with visual impairment. Ophthalmic Physiol Opt 2005;25:357- 62.
45. Williams GP, Pathak- Ray V, Austin MW, Lloyd AP, Millington IM, Bennett A. Quality of life and visual rehabilitation: an observational study of low vision in three general practices in West Glamorgan. Eye 2007;21:522-527.
46. Abdelhafiz AH, Austin CA. Visual factors should be assessed in older people presenting with falls or hip fracture. Age Ageing 2003;32:26-30.
47. Abyad A. In-office screening for age-related hearing and vision loss. Geriatrics 1997;52:45-6, 51-4, 57.
48. Lee PP, Feldman ZW, Ostermann J, Brown DS, Sloan FA. Longitudinal rates of annual eye examinations of persons with diabetes and chronic eye diseases. Ophthalmology 2003;110:1952-9.
49. Mangione CM, Gutierrez PR, Lowe G, Orav EJ, Seddon JM. Influence of age-related maculopathy on visual functioning and health- related quality of life. Am J Ophthalmol 1999;128:45-53.
50. Brody BL, Roch- Levecq AC, Thomas RG, Kaplan RM, Brown SI. Self- management of age-related macular degeneration at the 6- month follow-up: a randomized controlled trial. Arch Ophthalmol 2005;123:46-53.
51. Brody BL, Roch-Levecq AC, Gamst AC, Maclean K, Kaplan RM, Brown SI. Self- management of age- related macular degeneration and quality of life: a randomized controlled trial. Arch Ophthalmol 2002;120:1477-83.
52. Donohue B, Acierno R, van Hasselt VB, Hersen M. Social skills training in a depressed,visually impaired older adult. J Behav Ther Exp Psychiatry 1995;26:65-75.
53. Mann E, Koller M, Mann C, van der Cammen T, Steurer J. Comprehensive Geriatric Assessment (CGA) in general practice: results from a pilot study in Vorarlberg, Austria. BMC Geriatr 2004;4:4.
54. Hasin DS, Goodwin RD, Stinson FS, Grant BF.idemiology of major depressive disorder: results from the National Epidemiologic Survey on Alcoholism and Related Conditions. Arch Gen Psychiatry 2005;62:1097-106.
55. Beaudet MP. Depression. Health Rep 1996;7:11-24, 11-25.
56. West SL, Richter A, Melfi CA, McNutt M, Nennstiel ME, Mauskopf JA. Assessing the Saskatchewan database for outcomes research studies of depression and its treatment. J Clin Epidemiol 2000;53:823-31.