Optometry & Vision Science:
Medical Decision-Making Capacity and Cataract Surgery
Swanson, Mark W.*
*OD, MSPH, FAAO
School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama.
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.optvissci.com).
Received June 18, 2012; accepted July 16, 2012.
Mark W. Swanson University of Alabama at Birmingham School of Optometry 1716 University Blvd. Birmingham, Alabama 35294-0010 e-mail: firstname.lastname@example.org
Background. Medical decision making has evolved from a paternalistic, “doctor knows best system” to one of shared decision making between health care providers and patients. Shared decision making involves informed consent related to the proposed health care options and medical decision-making capacity by patients. Adults aged 90 and older are the fastest growing segment of the US population. Dementia prevalence increases dramatically among this group. Dementia may affect the ability of patients to participate in shared decision making.
Case Report. The case of a 91-year-old female rehabilitation inpatient with mild cognitive impairment, cataracts, and macular degeneration is presented. The case highlights key issues of informed decision making and medical decision-making capacity related to cataract surgery. Video examples of the assessment of cognitive and medical decision-making capacity are presented.
Adults aged >90 years represent the fastest growing segment of the United States (U.S.) population.1 The prevalence of dementia in older adults increases from slightly over 20% at age 80 to almost 40% by age 90.2,3 With the growth of the oldest-old population, clinicians will be increasingly called on to evaluate the medical decision-making capacity (MDMC) of these patients. Competency is a legal decision made by a judge where MDMC is the ability of an individual to self-determine the medical care they will or will not receive. An assessment of MDMC can be performed during an examination and does not require a specific evaluation by a psychologist or psychiatrist.4 Assessment of MDMC is done de facto on a daily basis by clinicians.
A 91-year-old inpatient is examined for evaluation as part of an interdisciplinary assessment to determine the potential of the patient to return to assisted living. The patient was admitted for a short-term rehabilitation stay within a skilled nursing facility (SNF) after an acute hospitalization for an upper respiratory infection vs. lung carcinoma. Before her hospitalization, the patient was living in the self-care assisted-living component of a continuous care retirement community.5 She became weak, short of breath, and febrile, requiring a hospital admission. During her hospitalization, a mass was discovered in the upper lobe of the right lung on computed tomography scan. It was unclear from the computed tomography whether the mass was infectious or cancerous. The patient refused bronchoscopy to differentiate the two. She was started empirically on intravenous vancomycin, and her status gradually improved. After a 2-week hospital stay, she was discharged to the SNF to complete antibiotic therapy, for rehabilitation to address her loss of muscle strength that occurred during hospitalization, to evaluate her mobility and fall risk, and ultimately make a decision on her ability to return to assisted living. After discharge, her oxygen saturation remained slightly decreased, and she continues on supplemental oxygen intermittently. In addition to the acute respiratory problem, she has mild stable congestive heart failure, moderate severity rheumatoid arthritis, and macular degeneration.
She was seen at the facility in bed, although she is typically ambulatory. She complained of poor vision in both eyes of several years duration. Her vision history was significant for cataract extraction in the OS. She has been told she has a cataract in the OD, but has been reluctant to have it removed. Although she has not seen him in several years, she was told by her retina specialist that cataract surgery might worsen the macular degeneration in her better eye. She is also concerned she is too old now to have surgery. Her current spectacles are old and no longer help much. Entering visual acuity without glasses using a Feinbloom chart was OD 5/100 and OS 5/400. With a super pinhole, she was able to achieve 5/20 in the OD, and there is no improvement in the OS. All preliminary testing was unremarkable. Retinoscopy was OD −2.50 to 1.00 × 095 with 5/80 acuity and OS + 0.50 to 2.50 × 175 with no improvement in visual acuity. Subjective refraction did not improve acuity. Anterior segment assessment shows a dense mixed cataract in the OD. She is status-post cataract extraction in the OS with posterior capsule intraocular lens. Dilated fundus examination showed a large scar consistent with inactive wet macular degeneration, covering the entire macular region of the OS. The OD showed soft drusen >125 μm, with pigment mottling and patches of retinal pigment epithelium drop out outside the central foveal zone. The findings are consistent with moderate-stage dry age-related macular degeneration (ARMD). The patient was screened for cognitive impairment using the short orientation memory and concentration test (Video, Supplemental Digital Content 1, available at: http://links.lww.com/OPX/A104, shows cognitive assessment) and was found to have cognitive loss, which would require further evaluation for dementia. A clinical assessment of MDMC was performed (Video, Supplemental Digital Content 2, available at http://links.lww.com/OPX/A105, shows questioning as part of capacity assessment). The patient was judged to have adequate MDMC for cataract surgery. Her care plan recommendation to the team from optometry was for cataract extraction in the OD.
Medical ethics in western societies have developed based on the concepts of informed consent and individual patient autonomy. In order to consent to a medical procedure, a patient must: 1) be given adequate information regarding the nature and purpose of proposed treatments, as well as the risks, benefits, and alternatives to the proposed therapy, including no treatment; 2) be free from coercion; and 3) have MDMC.4,6 There was a marked change in the past 25 years in medical decision making from paternalistic provider beneficence to a model based on patient autonomy.7 This case highlights two key components of the autonomy model: informed consent and MDMC.
In this case, the informed decision making involves several points and concerns: 1) is the patient too old to benefit from surgery or at high risk of morbidity secondary to sedation and anesthesia? 2) will cataract surgery worsen her ARMD? 3) will surgery improve her ability to return to assisted living? Based on 2008 U.S. census data, life expectancy for all adults aged 90 years is 4.6 years and for adults aged 95 years is 3.6 years.8 Life expectancy, by itself, is a poor criteria in determining who should avoid cataract surgery. Life expectancy can be difficult to determine. Research across a variety of conditions has shown that physician's estimation of life expectancy is poor even among patients with terminal illness.9 Cataract surgery has almost immediate benefits with a rapid recovery period. Persons who delay or avoid surgery have been found to have lower quality of life than those who choose more immediate surgery.10 Cost per quality adjusted life year gained has been found to be favorable.11 Analysis based on quality-adjusted life year gained has shown a benefit for cataract surgery for men up to age 96 and women up to age 97 years.11
Cataract surgery itself has been shown to be safe even among the very elderly population.12 Data from the Veterans Administration have shown mortality rates in the 90 day postoperative period after cataract surgery to be lower among those undergoing surgery than in the age matched general U.S. population.12 Mortality in this population was low even among those with higher risk medical conditions, such as solid cancer, leukemia or myeloma, and chronic obstructive pulmonary disease.12 Among the oldest adults, vision improvement may be more modest because of coexisting visual problems (e.g., macular degeneration), whereas intraoperative and postoperative complications have been found to be no worse for adults in their 90s than for adults in their 80s.13
The American Society of Anesthesiologists (ASA) has devised a simple scheme for classifying the physical status of patients before surgery14 (Table 1). Although the ASA states that the system is not used for assessing anesthesia risk, it has extensively been used in that manner and has been shown to correlate with surgical morbidity and mortality.15 The ASA categories have been expanded by various groups to provide case examples.16 Most patients who undergo cataract extraction are in ASA physical status categories 1 to 3 with stable chronic disease and low surgical risk. Persons in category 4, such as those with symptomatic congestive heart failure, unstable angina, symptomatic chronic obstructive pulmonary disease, renal and liver failure, do require more careful consideration of the risks and potential benefits. Even in these higher-risk patients, day of surgery mortality and cardiac events during cataract surgery approach zero.17
The role of cataract surgery in exacerbating macular degeneration has been and remains controversial. Data from the Blue Mountains and Beaver Dam studies have indicated a higher rate of end-stage macular degeneration among those having had cataract surgery than without.18 Recent reanalysis of data from the Beaver Dam and Rotterdam studies have suggested an interaction between cataract surgery and ARMD susceptibility genes.19 Conversely, data from the Age-Related Eye Disease Study have shown that patients with all stages of macular degeneration benefit from cataract surgery and that improvement in visual acuity appears stable for at least 18 months after surgery.20 Similarly, an analysis of data from the Antibody for the Treatment of Predominantly Classic Choroidal Neovascularization in Age-Related Macular Degeneration trial and the Minimally Classic/Occult Trial of the Anti-VEGF Antibody Ranibizumab in the Treatment of Neovasular Age-Related Macular Degeneration reported that cataract surgery was safe and beneficial for all eyes with macular degeneration, including those treated with ranibizumab.21 Using Beaver Dam and Blue Mountains data, number needed to harm analysis shows for every 20 people who have cataract surgery, one will develop late-stage ARMD within 10 years that otherwise would not have (Swanson M, unpublished data).
The patient's ultimate goal is to return to assisted living. Short-term stays within an SNF are a crucial point in the U.S. health care system. These admissions are distinctly different from long-term care nursing home (LTCNH) admissions. Ideally during SNF stays persons will return to a level of function that would allow them to live independently in the community. Under economic pressures, hospitals are discharging patients sicker and quicker. Between 1996 and 2008, SNF admissions after hospitalization increased 60%.22 During this period, two-thirds of people admitted to an LTCNH after hospitalization had a prior SNF admission.22 This makes SNF stays an attractive target for health care cost reduction, with improved care potentially preventing more costly LTCNH admission.
Cataract surgery has not been studied as an intervention to reduce LTCNH placement. However, vision impairment and falls are both predictive of LTCNH admission.23 Cataracts have been associated with falls in numerous studies.24 The joint American/British Geriatric Societies clinical practice guideline on falls recommends addressing vision impairment as a component of their overall fall reduction strategy.25 Although it is unknown whether cataract surgery reduces LTCNH admission, it is known that vision-specific quality of life, irrespective of acuity, improves dramatically after cataract surgery even among adults aged 90 years and older.26
A number of medical conditions may affect MDMC. Lack of MDMC is high among those with developmental disability (68%), dementia (52%), and among nursing home residents (44%).4 MDMC is not an absolute. A person may have capacity for some decisions (new spectacles) but not for others (end of life care).4,6 Capacity may change as acute medical status changes (e.g., delirium). As with many older adults, cognitive status was a concern in this case. Cognitive status only predicts MDMC at the upper and lower extremes. Mildly impaired cognitive status does not always mean lack of capacity.4,6 A variety of mental status screening tests are available for use in clinical practice. For many years, the Folstein Mini-Mental State Examination was the most commonly used cognitive screener for older adults. After years in the public domain, it became the target of stealth patent making its routine use more difficult.27 The short orientation memory and concentration test or short blessed test28 is an easily administered alternative. It has high sensitivity and specificity for dementia and correlates well with the Folstein.28 The scoring algorithm weighs items differently with error scores >9 indicative of persons needing further workup for dementia.28 In this case, the patient had three errors: the year, counting backward from 20, and one item on the address memory item (errors in the street name are not counted) for a weighted score of 10. This score falls in the gray area of mild cognitive impairment where MDMC may or may not be present.
A number of formal tools for evaluating MDMC exist.4,6 During examination, clinicians can assess MDMC informally through directed interview, as was done in this case.29 All assessments of MDMC have in common checks of the ability to understand the relevant information, the ability to appreciate the medical consequences of the decision, the ability to reason about treatment choices, and the ability to communicate a choice and be consistent in their wishes4,6 (Video, Supplemental Digital Content 3, available at: http://links.lww.com/OPX/A106, shows consistency of patient preferences). If patients are judged not to have MDMC, it becomes an issue of surrogacy. Under the best of circumstances, the patient will have an advanced directive or have a named health care proxy, the surrogate.29 Even when available advanced directives often do not cover procedures like cataract surgery. As a health care proxy, the surrogate will need to make decisions based on principles of “substituted judgment” (what the patient would have decided) or “best interest” (what the surrogate judges to be best for the patient).29 Surrogate decision makers have been shown to have poor correlation with patient wishes for cataract surgery.30
Adults >90 years represent the fastest growing segment of the U.S. population. Because of the high prevalence of cognitive impairment in this group, the MDMC of this population can be an issue. As this case demonstrates, cognitive status and MDMC can be assessed in the course of clinical examination.
SUPPLEMENTAL DIGITAL CONTENT
Supplemental digital content are available online at: http://links.lww.com/OPX/A104, http://links.lww.com/OPX/A105, and http://links.lww.com/OPX/A106.
Mark W. Swanson
University of Alabama at Birmingham
School of Optometry
1716 University Blvd.
Birmingham, Alabama 35294-0010
Appropriate subject releases for publication of the video files were received.
2. Plassman BL, Langa KM, Fisher GG, Heeringa SG, Weir DR, Ofstedal MB, Burke JR, Hurd MD, Potter GG, Rodgers WL, Steffens DC, Willis RJ, Wallace RB. Prevalence of dementia in the United States: the aging, demographics, and memory study. Neuroepidemiology 2007;29:125–32.
3. Corrada MM, Brookmeyer R, Paganini-Hill A, Berlau D, Kawas CH. Dementia incidence continues to increase with age in the oldest old: the 90+ study. Ann Neurol 2010;67:114–21.
4. Sessums LL, Zembrzuska H, Jackson JL. Does this patient have medical decision-making capacity? JAMA 2011;306:420–7.
6. Appelbaum PS. Clinical practice. Assessment of patients' competence to consent to treatment. N Engl J Med 2007;357:1834–40.
7. Pellegrino ED, Thomasma DC. The conflict between autonomy and beneficence in medical ethics: proposal for a resolution. J Contemp Health Law Policy 1987;3:23–46.
9. Kistler CE, Lewis CL, Amick HR, Bynum DL, Walter LC, Watson LC. Older adults' beliefs about physician-estimated life expectancy: a cross-sectional survey. BMC Fam Pract 2006;7:9.
10. Lamoureux EL, Fenwick E, Pesudovs K, Tan D. The impact of cataract surgery on quality of life. Curr Opin Ophthalmol 2011;22:19–27.
11. Weale M. A cost-benefit analysis of cataract surgery based on the English longitudinal survey of ageing. Available at: http://www.niesr.ac.uk/pdf/dp349.pdf
. Accessed May 6, 2012.
12. Greenberg PB, Liu J, Wu WC, Jiang L, Tseng VL, Scott IU, Friedmann PD. Predictors of mortality within 90 days of cataract surgery. Ophthalmology 2010;117:1894–9.
13. Rosen E, Rubowitz A, Assia EI. Visual outcome following cataract extraction in patients aged 90 years and older. Eye (Lond) 2009;23:1120–4.
15. Khuri SF, Daley J, Henderson W, Hur K, Gibbs JO, Barbour G, Demakis J, Irvin G 3rd, Stremple JF, Grover F, McDonald G, Passaro E Jr., Fabri PJ, Spencer J, Hammermeister K, Aust JB. Risk adjustment of the postoperative mortality rate for the comparative assessment of the quality of surgical care: results of the National Veterans Affairs Surgical Risk Study. J Am Coll Surg 1997;185:315–27.
17. Schein OD, Katz J, Bass EB, Tielsch JM, Lubomski LH, Feldman MA, Petty BG, Steinberg EP. The value of routine preoperative medical testing before cataract surgery. Study of Medical Testing for Cataract Surgery. N Engl J Med 2000;342:168–75.
18. Wang JJ, Klein R, Smith W, Klein BE, Tomany S, Mitchell P. Cataract surgery and the 5-year incidence of late-stage age-related maculopathy: pooled findings from the Beaver Dam and Blue Mountains eye studies. Ophthalmology 2003;110:1960–7.
19. Klein BE, Howard KP, Lee KE, Iyengar SK, Sivakumaran TA, Klein R. The relationship of cataract and cataract extraction to age-related macular degeneration: The Beaver Dam Eye Study. Ophthalmology 2010.
20. Forooghian F, Agrón E, Clemons TE, Ferris FL 3rd, Chew EY. Visual acuity outcomes after cataract surgery in patients with age-related macular degeneration: age-related eye disease study report no. 27. Ophthalmology 2009;116:2093–100.
21. Rosenfeld PJ, Shapiro H, Ehrlich JS, Wong P. Cataract surgery in ranibizumab-treated patients with neovascular age-related macular degeneration from the phase 3 ANCHOR and MARINA trials. Am J Ophthalmol 2011;152:793–8.
22. Goodwin JS, Howrey B, Zhang DD, Kuo YF. Risk of continued institutionalization after hospitalization in older adults. J Gerontol A Biol Sci Med Sci 2011;66:1321–7.
23. Tielsch JM, Javitt JC, Coleman A, Katz J, Sommer A. The prevalence of blindness and visual impairment among nursing home residents in Baltimore. N Engl J Med 1995;332:1205–9.
24. Michael YL, Lin JS, Whitlock EP, Gold R, Fu R, O'Connor EA, Zuber SP, Beil TL, Lutz KW. Interventions to Prevent Falls in Older Adults: An Updated Systematic Review. Rockville, MD: Agency for Healthcare Research and Quality; 2010. Report No.: 11-05150-EF-1.
25. The American Geriatrics Society; American Geriatrics Society (AGS)/British Geriatrics Society (BGS) Clinical Practice Guideline: Prevention of Falls in Older Persons. Summary of the Updated American Geriatrics Society/British Geriatrics Society Clinical Practice Guideline for Prevention of Falls in Older Persons. Developed by the Panel on Prevention of Falls in Older Persons, American Geriatrics Society and British Geriatrics Society, 2010. Available at: http://www.americangeriatrics.org/health_care_professionals/clinical_practice/clinical_guidelines_recommendations/2010/
. Accessed May 6, 2012.
26. Rosen E, Rubowitz A, Assia EI. Visual outcome following cataract extraction in patients aged 90 years and older. Eye (Lond) 2009;23:1120–4.
27. Newman JC, Feldman R. Copyright and open access at the bedside. N Engl J Med 2011;365:2447–9.
28. Katzman R, Brown T, Fuld P, Peck A, Schechter R, Schimmel H. Validation of a short orientation-memory-concentration test of cognitive impairment. Am J Psychiatry 1983;140:734–9.
29. Tunzi M. Can the patient decide? Evaluating patient capacity in practice. Am Fam Physician 2001;64:299–306.
30. Mantravadi AV, Sheth BP, Gonnering RS, Covert DJ. Accuracy of surrogate decision making in elective surgery. J Cataract Refract Surg 2007;33:2091–7.
cognitive status; medical decision-making capacity; cataract surgery; macular degeneration
Supplemental Digital Content
© 2012 American Academy of Optometry
Highlight selected keywords in the article text.