Physicians frequently fail to identify impaired medical decision-making capacity. Institution: Icahn School of Medicine at Mount SinaiArticle CitationArticle Link: Does this patient have medical decision-making capacity? Clinical Bottom Lines Impaired medical decision-making capacity is prevalent among several patient populations: 26% among hospital inpatients (95%CI, 18%-35%) and 44% among nursing home residents (95%CI, 28%-60%). Physicians were only able to identify incapacity in 42% (95%CI, 30%-53%) of these patients. The Aid to Capacity Evaluation (ACE) is recommended by the authors as a superior instrument for assessing medical decision-making capacity given its favorable likelihood ratios (LR+, 8.5; 95% CI, 3.9-19; LR−, 0.21; 95% CI, 0.11-0.41) when compared against a gold standard and given that the ACE instrument is based on an actual decision that a patient is facing. Disclaimer: This is a review of the validity of a single study; the ‘bottom lines’ do not reflect comparison with the rest of the literature on this subject. MethodsType of Study: Diagnostic TestFollow-up Period: N/APatient Population: MEDLINE and EMBASE databases from their inception to April 2011 were searched using a variety of search terms including "competency", "informed consent" OR "treatment refusal" OR "mental competency." The search was restricted to English-language articles that evaluated instruments assessing medical decision-making capacity for treatment decisions. The search further focused on instruments that were determined to be feasible to use in the office or at the bedside. Forty-three studies were included in the review and pooled analysis, representing a total of 3864 study participants. Among studies reporting subject characteristics, the average age was 65.5 years (n=40 studies), 48% were male (n=34 studies) and 84% were white (n=15).Significant Exclusions: Studies that focused solely on capacity to participate in research, on medical decision making for psychiatric patients, such as involuntary admission or treatment, or those that focused solely on assessing cognition were excluded.Intervention/Exposure: Nineteen different instruments for assessing capacity were identified in the review, nine of which were studied in comparison to a gold standard. Gold standards varied and included independent assessments by forensic psychiatrists, expert psychiatrists, competency panels and multidisciplinary competency panels. Three instruments were highlighted which are possible to perform in an office visit or at the bedside and which had favorable likelihood ratios and moderate to strong levels of evidence. These were the Aide to Capacity Evaluation (ACE), the Hopkins Competency Assessment Test (HCAT), and the Understanding Treatment Disclosure (UTD).Outcome Measures: PRIMARY OUTCOME: Studies assessed the accuracy of the various instruments in diagnosing incapacity to make medical decisions. Sensitivity, specificity and likelihood ratios were calculated from raw data. SECONDARY OUTCOMES: Data were pooled to determine: (1) The prevalence of patients lacking capacity across different diseases or patient care settings (2) The relationship between capacity scores and cognition (as determined by the MMSE) (3) The rate of recognition of incapacity by patients' physicians Results The ACE, when compared against the gold standard of an assessment conducted by a forensic psychiatrist, was determined to be the best available instrument to assess capacity given the favorable likelihood ratio for identifying incapacity (LR+, 8.5; 95%CI: 3.9-19; LR-,0.21; 95%CI: 0.11-0.41), the ability to perform it in less than 30 minutes in an office setting or at the bedside, and the fact that it is specific to the actual decision being made by the patient rather than assessing capacity based on a generic and fabricated scenario. It could be argued that the ACE, in addition to being a diagnostic instrument for assessing capacity, is actually an excellent template for medical decision making and informed consent discussions given that it is situation specific and comprehensive. There was a notable relationship between capacity and cognition. MMSE scores of greater than 24 were associated with a decreased likelihood of incapacity (summary LR 0.14; 95%CI: 0.06-0.34) and scores of less than 20 were associated with an increased likelihood of incapacity (summary LR 6.3; 95%CI: 5.3-27.5). Prevalence estimates of incapacity varied across the types of patient populations studied. Healthy older adults had the lowest prevalence of incapacity at 2.8% (95%CI, 1.7-3.9) and learning disabled subjects had the highest prevalence of incapacity at 68% (95%CI, 41-97%). Physicians were found to identify incapacity in only 42% of those patients independently determined to lack capacity (95%CI, 30%-53%). While the diagnosis of incapacity is frequently missed, physicians were found to be accurate when they do make the diagnosis ([LR+], 7.9; 95%CI, 2.7-13). Methodological Issues… This systematic review involved heterogeneous interventions, settings, populations and outcomes which limits the authors' ability to draw conclusions about the clinical applicability and generalizability of utilizing different instruments to assess capacity in different settings and with different patient populations. Other InformationCreated By: Allison Stark, MD, Fellow, Mount Sinai School of Medicine, Department of Geriatrics and Palliative Medicine CAP Topics: Geriatric Assessment [1]Advance Care Planning [2]
