The Pavia Capacity Scale: A novel approach to standardize the assessment of general capacity in clinical practice

Capacity is a fundamental prerequisite for any patient to be deemed able to provide informed consent (IC) to any medical procedure. IC has been established as a fundamental human right by UNESCO that must be respected by all medical practitioners both ethically and legally. While commonly dichotomized, Capacity, in reality, is a spectrum ranging between the absolute extremes. The Pavia Capacity Scale (PCS) has been developed with a view to assisting less experienced physicians to gauge the appropriate means of obtaining informed consent, particularly in fragile populations. Four variables are used to determine what is termed herein as ‘general capacity’ (a concept analogous to how the GCS is used to assess global neurological status). These variables are: 1) The Glasgow Coma Scale (GCS), 2) the age of the patient, 3) a history of mental illness and/or drug/medication use, and 4) an assessment of communication & language barriers. Co-efficients for the latter three parameters modulate the GCS score to produce a PCS score that makes recommendations depending on the degree of impairment as well as differentiating between emergent/urgent and elective/outpatient circumstances. Recommendations form a gradient which is expected to be modulated by clinical circumstance as well as other variables which are not considered in the tool such as socio-cultural-religious values and education. Due to the COVID-19 pandemic, the PCS variables have not been assessed clinically but approximated using hypothetical case studies and in consultation with expert working physicians. This tool is intended to assist all healthcare practitioners in helping to standardize what is currently an arbitrary determination of patient capacity. It is hoped that implementation of this tool will assist physicians who are treating fragile populations and enable them to practice medicine in a more ethical manner.