Decision-making capacity in older medical in-patients: frequency of assessment and rates of incapacity by decision-type and underlying brain/mind impairment

BACKGROUND: Hospital clinicians find mental capacity assessment challenging and may lack the necessary skills. Given high rates of cognitive impairment, data on mental capacity assessment in real-world hospital cohorts are required to inform the need for staff training and workforce planning. OBJECTIVES: In unselected medical inpatients, we determined the rate and outcome of mental capacity assessment by decision type and underlying brain/mind disorder, and recorded the discipline of the assessor. METHODS: We included consecutive patients (October–November 2018; November–December 2019) admitted to the complex medicine unit providing acute multidisciplinary care for multi-morbid patients (age ≥ 16 years, average age > 80 years). Audit data were collected at ward multidisciplinary meetings and extracted from electronic patient records. RESULTS: Among 892 patients (mean/SD age = 82.8/8.6, 465 male), 140 (16%) required mental capacity assessment (40/140 (29%) had ≥2 assessments) with 203 assessments in total of which 162 (80%) were done by doctors. Capacity was deemed lacking in 124 (61%) assessments, most commonly in delirium with/without other co-morbid conditions (94/114, 82%) or dementia (9/12, 75%) with lower rates in other disorders (15/27, 56%), and no formal diagnosis of brain/mind disorder (6/50, 12%). Cognitive test scores were overall lower in those lacking capacity (mean/SD abbreviated-mental-test-score = 5.2/2.6, range = 0–10 versus 6.8/2.8, P = 0.001, range = 1–10). Decisions involving discharge planning were most often assessed (48%) followed by treatment (29%), discharge against medical advice (12%) and others (11%). CONCLUSION: Mental capacity assessments were performed frequently and often repeated, justifying the need for robust training in the practical application of the principles of capacity assessment for staff managing complex older patients.