Who can decide? Prevalence of mental incapacity for treatment decisions in medical and surgical hospital inpatients in Ireland

Abstract

Background The prevalence of mental incapacity for treatment decisions among medical and surgical hospital inpatients is poorly understood or not known in many countries, including Ireland. Aim To assess the prevalence of mental incapacity in hospital inpatients in Ireland. Design Cross-sectional observational study of mental incapacity for treatment decisions. Methods We assessed mental capacity in 300 randomly selected hospital inpatients in 2 general hospitals in Dublin (urban) and Portlaoise (rural), in Ireland, using the MacArthur Competence Assessment Tool for Treatment (MacCAT-T). Results Mean MacCAT-T score was 14.80 (SD: 8.40) out of a possible maximum of 20 (with a higher score indicating greater mental capacity). Over one quarter of participants (27.7%; n = 83) lacked the mental capacity for treatment decisions; 1.7% (n = 5) had partial capacity and 70.7% (n = 212) had full capacity. Scores for each of the four sub-scales of the MacCAT-T were generally consistent across the four key areas of understanding, appreciation, reasoning and expressing a choice. Conclusions Mental incapacity for treatment decisions is common in medical and surgical hospital inpatients in Ireland. This issue both merits and requires greater attention in clinical practice, research and legislation.