Alastair Macdonald

Here we describe how more important findings were obtained in a delirium study by using an informal assessment of mental capacity, and, in those who lacked capacity, obtaining consent later when or if capacity returned or a proxy was found. From a total of 233 patients 23 patients lacked capacity as judged by our informal capacity judgment and 210 did not. Of those who lacked capacity, 13 agreed to enter in the study. Six of them regained capacity later. When these 13 participants were excluded from analysis, significant findings were no longer evident. These results show that by the inclusion of subjects who lacked capacity the results of analyses of the condition from whish they suffer are altered. We suggest that this approach to the study of delirium is more ethical than the usual system of strict exclusion of people who lack capacity to give consent and for whom assent is not available.

Legal frameworks are in place to protect those who lack the capacity to consent to research, such as the Mental Capacity Act in the UK. Assent is sought instead from a proxy, usually a relative. However, the same legislation may, perversely, affect the welfare of those who lack capacity and of others by hindering the process of recruitment into otherwise potentially beneficial research. In addition, the onus of responsibility is moved from those who know most about the study (ie, the scientific community) to those who know less (the proxies). In this paper, we describe the characteristics of a sample at different stages of the recruitment process of an influenza vaccine-based randomised control trial in elderly care home residents (the FEVER study). 62% (602/968) of potential subjects lacked capacity but only 29% (80/277) of those actually randomised. Older age, being female and living in an Elderly Mentally Ill care home were the only variables associated with lacking capacity. Considering this was a study based in a care home setting where the prevalence of dementia approximates 80%, the trial, like many others, was thus significantly biased. We believe that difficulties seeking proxy assent contributed significantly to this problem. Further thought should be given to how assent to enter research for those who lack capacity should be provided, and we suggest avenues for further discussion such as independent risk/benefit expert panels