Background The Law Commission of Aotearoa/New Zealand has just announced a review into the laws on adult decision-making capacity including potential alignment with the UN Convention of the Rights of Persons with Disabilities. New Zealand’s current legislation, the Protection of Personal and Property Rights Act 1988 applies a substituted decision-making framework where another person is appointed to make the decision for them. This is at the expense of a supported decision-making framework. This is acknowledged to have an impact on advance care planning. Understanding how people use advance care plans (ACP plans) to make decisions ahead of an emerging crisis may help us understand education requirements of people contemplating advance care planning in the future and help inform the review.

Methods Retrospective, aggregated non identifiable quantitative data from complete electronic advance care plans from the South Island of New Zealand (1.1 million) was analysed using a simple descriptive approach.

Results Data from 7148 ACP plans we analysed, 1722 were excluded due to draft/deleted status, 5426 (76%) of plans were included. 5184(96%) included advance preferences around goals of care, 3901 (72%) listed a legal substitute decision maker, 1213 (22%) nominated people they wanted to involved in decision making, and 1178 (22%) supported substituted decision makers being allowed to inform decisions even if it is not agreed in the plan. 4221(78%) indicated what mattered to them, 2805 (52%) indicated what suffering meant, 2370 (43%) indicated worries, 3735(69%) indicated priorities if time was limited. 4260 (79%) indicated limitations to treatment around resuscitation.

Conclusion Most people completing advance care plans nominate legal substitute decision makers and indicate advance preferences for goals of care. Fewer provide the breadth and depth of information that would assist effective supported decision making, so the Law Commission Review is likely to significantly impact the framework of ACP plans.