Vol. 137 No. 1598 |

DOI: 10.26635/6965.6474

Examining the approaches used to assess decision-making capacity in healthcare practice

Decision-making capacity (DMC) denotes the capability to make a decision at a specific time. Healthcare professionals are responsible for conducting DMC assessments, but the outcome can have indefinite legal consequences for an individual.

Full article available to subscribers

Decision-making capacity (DMC) denotes the capability to make a decision at a specific time. Healthcare professionals are responsible for conducting DMC assessments, but the outcome can have indefinite legal consequences for an individual.1 Informal DMC assessment occurs frequently by healthcare practitioners as part of the legal and ethical responsibility to obtain informed consent for treatment.2 Formal DMC assessment occurs when an individual’s DMC has been called into question and an assessment is required for legal purposes in examples, such as under the Protection of Personal and Property Rights Act (PPPR) 1998 or capacity to make a will.1 A formal DMC assessment should assess an individual’s ability to understand the information given, retain the information for a required time, use and weigh the information and communicate a decision.1 Many DMC assessments are straightforward, but others can be complex and require extensive ethical, reflective and adaptive approaches.3 This may be due to several different factors—for example, subtle or fluctuating cognitive impairment such as dementia,4 mental illness and involvement of mental health acts,5 aphasia,6 persons with disabilities7 or differing professional opinions.8

Recent Australasian research has highlighted concerns with how DMC assessments are being conducted, and provided evidence of considerable variation.9–13 For example, a survey of Australian healthcare practitioners found that 31% of DMC assessors used a capacity assessment tool, 52% used a screening tool and 77% used professional judgement11 despite it being argued that screening tools are not suitable for DMC assessment and should not be used.14 Documentation of DMC assessments is also varied. A retrospective case note review in Australia found that 33% of patients referred for guardianship applications had no documented evidence of a completed DMC assessment.10

While doctors appear to be conducting most DMC assessments in New Zealand,12,15 it is a task also performed by nurse practitioners and clinical psychologists/neuropsychologists.16 Nurse practitioners have a wide range of assessments within their scope17 while clinical psychologists/neuropsychologists are trained in the use of various in-depth assessments.18 Research in Australia has found that healthcare professionals of multi-disciplines are often involved,6,19 while in other jurisdictions such as England and Wales, social workers and speech-language therapists are responsible for conducting DMC assessments under the Mental Capacity Act 2005 (England and Wales).20

Although it is known that the current approaches to assessing DMC vary, to the best of our knowledge there is no research in New Zealand that has captured exactly how these assessments are being conducted, who they are being conducted by and which tools and approaches are being used. The aim of the study was to understand the approaches that are being used in DMC assessments in New Zealand by those conducting them and those who identify as being involved in or contributing to them. It was anticipated that this could be used to indicate what, if any, practice or training changes are needed. At the time of this study the End of Life Choice Act 2019 was a relatively new legislation in New Zealand. Given that this Act is the only circumstance in which DMC is not presumed and an assessment must be completed, we included a question in our survey to explore how the Act has impacted DMC assessments in this new clinical situation.


Survey design

The first author designed the survey after completing a detailed review of Australasian literature on DMC assessments. The co-authors provided feedback on the content and flow. The survey was administered through QualtricsXM (a web-based survey tool). Table 1 provides the six survey questions about current approaches used to assess DMC. The questions listed here are a selection from a larger project (see for full survey questions and analysis).

Following ethics approval (reference number UAHPEC: 23678), data were collected between January and April 2022. All responses were anonymous and no identifiable information was gathered in the questionnaire.


Participants were recruited through various professional colleges (namely General Practitioners [GP], Psychiatry and Clinical Psychology) and associations (representing nurse practitioners, speech-language therapists, occupational therapists, social workers and psychologists). Relevant community organisations and interest groups were also contacted. All participants needed to have met the eligibility criteria of being a healthcare professional with some involvement in DMC assessments, having read the participant information sheet and agreeing to participate.

Data analysis

Data collected on QualtricsXM were downloaded to Microsoft Excel (2022). Participants were classified into two groups. The first group were those healthcare professionals who commonly conduct DMC assessments (namely, medical practitioners, nurse practitioners and clinical psychologists/neuropsychologists); referred to as the “conducting” group. All other healthcare professionals who identified as being involved in DMC assessments were referred to as the “contributing to” group (largely consisting of social workers, speech-language therapists, occupational therapists and nurses). Descriptive analysis was used to compare the responses provided by both groups. The survey included several open-ended questions, and an inductive qualitative content analysis (informed by Elo and Kyngäs21) was undertaken to analyse these responses.

View Table 1–4.


A total of 171 participants opened the survey and met eligibility criteria (via self-identifying). Ninety-three (54.4%) participants did not complete the survey, with the majority (n=53, 57.0%) dropping out after the first two questions. This left 78 (45.6%) fully completed responses. The results analysed and presented here were for those 78 completed responses. The demographics for the “conducting” and “contributing to” groups are shown in Table 2.

Awareness and use of tools or approaches

When answering the open text Question 1 (requesting a list of tools or approaches they are aware of or use), participants provided a wide variety of responses (shown in Table 3). More than one approach was spontaneously mentioned by 55 (70.5%) participants. Bedside cognitive tests were more commonly reported by those in the “contributing to” group (41.9%, compared to 12.8% in the “conducting” group). They also named more other structured tools such as the Cognistat Cognitive assessment and the Allen’s Cognitive Level Screen. Those in the “conducting” group mentioned more of the available guidelines to assist in the assessment of DMC, namely the Toolkit for Assessing Capacity1 along with “Peter Darzin’s 6 step capacity assessment process22 and “various teaching mnemonics e.g., Play Soccur”, an assessment procedure detailed by Young23 covering presenting complaint, situation, options, consequences, consistency, undue influence, reasoning and executive ability.

Table 4 summarises responses to question 2; the prompted use of each tool or approach. Bedside cognitive tests were reported as the most commonly used by both groups. Among the 18 (38.3%) participants in the “conducting” group who reported using bedside cognitive tests most often, six (33.3%) also selected at least one other tool/approach that they use most often, four (22.2%) did not select any others for using most often but selected at least one for use sometimes, and eight (44.4%) selected bedside cognitive test as the only tool/approach used. The MacArthur Competence Assessment Tool for Treatment (MacCAT-T),24 which is arguably considered the gold standard for assessing DMC overseas,15 is not being used as the most common approach by anyone surveyed, with only 13 (27.7%) of those in the “conducting” group aware of the tool but not using it. Nearly one-third (31.9%) of those in the “conducting” group are using a structured clinical interview as one of their most common approaches, while 13 (27.7%) participants in this group are not aware of the approach. Other approaches mentioned were “United Kingdom structure for assessments”, “form developed by our service”, “unstructured clinical interview” and “supported needs assessments.

The Toolkit for Assessing Capacity1 is a semi-structured guideline designed in New Zealand and adopts the functional test of mental capacity as in the Mental Capacity Act 2005 (England and Wales).20 It is designed to help multidisciplinary healthcare professionals involved in the assessment of DMC and is regarded as the legal and professional standard under the Health and Disability Services Consumers’ Code of Rights. Given the significance of this locally developed tool, we asked participants about their awareness and use of it in a separate question. Just over half (51.1%) of those in the “conducting” group were aware of the toolkit with 11 (23.4%) using it as their most common approach. One fifth (21.3%) were aware of the toolkit but not using it. A similar level of awareness was also seen among those in the “contributing to” group with 13 (41.9%) stating they were aware of this approach.

Current processes and approaches

Question 3 elicited open-ended comments about the current processes and approaches in place for DMC assessments. Analysis of these comments highlighted four key concerns. The two most mentioned concerns were “quality issues” and “consistency/standardisation” with legal components and complexities of the concept of “partial capacity” also mentioned. Partial capacity refers to when an individual may be able to show evidence of some but not all elements of DMC, such as the ability to understand, retain and communicate but may struggle with weighing up options. DMC was commonly recognised as potentially having significant consequences on an individual’s life, requiring a robust process that reflects these consequences. Comments on quality issues included concerns about the current workplace processes being ad hoc and DMC reports lacking detail: “The court system should not allow people to be stripped of their decision-making rights based on an inadequate form that doctors fill in that does not involve any form of comprehensive capacity assessment, lacks detail and is carried out by a clinician who has not been trained in assessing capacity. One participant noted a practice of concern: “I’ve had GPs write complete forms for, with the guardianship under the Personal Properties and Rights Act. But, they’ve done that without even seeing somebody, because they had a low MoCA, you know, six months ago. Time pressures were acknowledged by participants as a constraint on conducting comprehensive DMC assessments in the public system.

Consistency and standardisation were raised as issues in approaches to assessing DMC: “The current system and processes are not comprehensive enough. There needs to be a standardised and effective decision-making capacity assessment which is rolled out and implemented nationally. This area of clinical practice was reported to be devoid of uniform guidelines to aid assessors in the process of assessing DMC: “There needs to be proper guidelines and policies for how exactly we do this. It’s very grey and to take someone’s capacity away without proper guidelines in New Zealand is a concern.

Participants highlighted the complex nature of “partial capacity” and the interaction it has with the law. One participant said, “It can feel like a ‘yes they have capacity’ or ‘no they don’t have capacity’ rather than decision specific approaches and that often I would consider clients to have ‘partial capacity’ which is not helpful with PPPR.” One participant went further to say that I would like to see our PPPR legislation change to allow that capacity assessment be decision-specific and to incorporate supported decision-making concepts.” Several comments were made about the need to move towards supported decision making and align better with the United Nations Convention on the Rights of Persons with Disabilities.25

End of life

When asked about the impact of the End of Life Choice Act (2019) in New Zealand, 19 (40.4%) participants in the “conducting” group felt that changes in the assessment of an individual’s DMC are required. However, the same number responded that they were unsure if changes are needed, and the remaining nine (19.1%) participants felt that changes are not needed. The majority (54.8%) of participants in the “contributing to” group were unsure if changes are needed, with 13 (41.9%) stating that changes are needed and one person (3.2%) stating that changes are not needed.

For those who responded that changes are required, an open-ended question captured their suggestions. Comments in the “conducting” group mostly focussed on the need for a clear and consistent approach with a firm standard that is nationally recognised, followed by comments focussed on training needs and skill, e.g., “Standard test—country wide used by formally trained clinicians”, “Much better training and consistency in approach to assessment.” Comments were also made about the need to recognise partial capacity and the lack of involvement of psychologists in the Act. Those in the “contributing to” group also mentioned that the Act potentially overlooks the role of other healthcare professionals and the need for clinician training.


DMC assessments are important clinical tasks that can have significant medico-legal consequences. They should therefore be comprehensive, robust and reliable. This cross-sectional survey supports previous research findings that those conducting DMC assessments are using a variety of different approaches9–11 and there is a desire for a move towards a more standardised approach.12,13

This is the first study in New Zealand to explore the approaches being used to assess DMC by both those conducting and those contributing to them. Spontaneous and prompted responses highlighted that DMC assessments can be ad hoc and conducted using a multitude of different tools following varied, often locally developed, guidelines. Bedside cognitive tests were reported to be used by many participants surveyed. For those who did not select any other tools/approaches it would suggest that some clinicians are continuing to rely on these limited tests as a measure of capacity.13 The surveyed healthcare professionals contributing to DMC assessments show just as much variation in what they use, potentially highlighting the level of knowledge held by some of those assisting but not commonly conducting DMC assessments. Given recent evidence to suggest that those not conducting DMC assessments feel that they do not have enough involvement,26 there may exist an opportunity to better utilise this knowledge.

This study found that within individual clinicians the approach to assessing DMC can change. It has been argued that, for decisions that are deemed to be more serious or when a patient is acting against what is perceived to be in their best interests, a more involved DMC assessment is completed.27 Furthermore, for more complex presentations it has been suggested that a more thorough assessment is needed, including referrals to specialists.28 However, the determination of what is a complex assessment is a grey area and relies on the subjectivity of the assessor to ascertain the level of seriousness and as such, the level of formality of the assessment, likely leading to increased variability. Most participants in this study were very experienced clinicians, many of whom raised the issue of consistency and quality within these assessments. It is therefore likely that the results of this study under-estimate the issue if one also considers the less experienced clinicians in the workforce. It may be that learnings can be taken from the interRAI32 system that is currently operating in the older adults sector in New Zealand. The interRAI provides a nationally standardised (and internationally validated) assessment to determine the appropriate level of care for individuals and is accessible by all clinicians working in this sector.

Partial capacity is an area of clinical practice that is not currently well understood or accounted for in the PPPR Act, with patients often being determined to wholly lack capacity and substitute decision making being the common outcome. As stated in the Toolkit for Assessing Capacity,1 DMC assessments should be decision-specific; however, assessment outcomes that state an individual wholly lacks capacity is arguably incorrect as in many instances they may lack DMC to make more complicated decisions about their care, but retain the DMC for everyday cares, e.g., the decision to shower. With DMC assessments often focussed on cognition, individuals with intellectual disabilities are more likely to be found to wholly lack capacity and have their decision-making rights taken away.7 As a ratifying nation, New Zealand has a duty to adhere to the United Nations Convention on the Rights of Persons with Disabilities.25 The Convention positions itself to put efforts, wherever possible, into involving an individual in the decision making. A move towards more supported decision-making practices as opposed to substitute decision making is warranted and requested from healthcare professionals.

Assisted dying is now legal in New Zealand, so it is concerning that most participants in this survey stated that changes are needed to the very assessment that determines if people are capable of making this decision. There was a clear request for a more standardised process that is uniform across the country and, supporting previous research among New Zealand-based psychiatrists,29 and a recent viewpoint,30 there was desire for increased knowledge and training for those conducting DMC assessment within this space.


DMC assessments need to be held to a clinical and legal nationally recognised standard with all healthcare professionals having access to formal training. It is suggested that a degree of flexibility will always be required given the inherent complexity of DMC and individual nuanced presentations. However, for straightforward cases patients should be receiving standardised assessments no matter who their clinician is, and for more complex cases there should always be the same starting point to limit the inherent variability. A detailed literature review proposed the Capacity Assessment Model of Practice.28 The model outlines the process, considerations and knowledge necessary for a well-conducted DMC assessment, of which it is recommended to be considered for development of a standardised guideline. It is hoped that the current review of adult DMC law being carried out by the Law Commission31 provides recommendations of a similar nature to those suggested in this study.

Strengths and limitations

This study is unique in its provision of detailed descriptions of how those involved in DMC assessments in New Zealand are assessing their patients. Combining qualitative and quantitative responses allowed for the reporting of clear data while adding depth and meaning to the responses. Open-ended questions have provided a clear direction for change. The small sample in this survey is the main limitation, limiting the analysis of assessment differences across individual professions. Demographics were not collected for those that did not complete the survey, and with a relatively high dropout rate we are unable to analyse the differences between those who completed the survey and those who did not. As we do not know the exact number of people who received the survey, we are unable to calculate the response rate and know if our results are representative of the healthcare workforce. It is likely that the participants who responded to the survey are those already engaged in this topic and therefore there is a sampling bias. Those who said no or unsure to changes being needed due to the End of Life Choice Act (2019) were not asked a follow-up question, thereby limiting our ability to analyse those responses. In addition, the spontaneous collection of approaches generated responses such as “a form developed by our service” and the survey did not allow for follow-up or clarification of responses to expand on what this was.

Future research

Change is required with a focus on providing clarity and detail on the current approaches and the changes required to ensure this area of clinical practice improves. As this is the first study in New Zealand to include those not currently recognised as conducting DMC assessments, more research is needed among this group. Research is also needed to ensure that changes made to the approach of DMC assessments are safe and culturally responsive to Māori and non-European ethnic groups. A co-design approach with key stakeholders could be considered when developing future DMC training courses to maximise end-user uptake of the resources.


Individual nuances within DMC mean that a flexible and adaptive response is likely to always be needed to some degree. However, this study provided evidence to show that the current approach to DMC assessment is widely varied, devoid of standards and has very little consistency. There is a call for a nationally recognised standard along with accredited training courses for how to approach and conduct these assessments.


To examine the approaches that are being used in New Zealand when conducting decision-making capacity (DMC) assessments among the healthcare professionals that commonly conduct DMC assessments and those that are involved in, but do not conduct, the assessments.


An online quantitative survey was conducted, lasting 10 minutes, including a mix of closed- and open-ended questions. The survey garnered responses from a total of n=78 participants.


Bedside cognitive tests were found to be the most commonly reported tool used to assess DMC among those conducting and those contributing to DMC assessments. Nearly a third (31.9%) of participants conducting DMC assessments used a structured clinical interview as one of their most common approaches while 27.5% of this same group reported not being aware of this approach. It was reported by both those conducting and those contributing to DMC assessments that the current standards lack quality and consistency, with partial capacity being poorly understood and identified, and supported decision making often being overlooked for substitute decision making.


Current approaches to DMC assessment lack standardisation and consistency, with assessment approaches being widely varied. This article serves as a call for the development of and adherence to nationally recognised standards for DMC assessments.


Nicola Hickling: Doctorate of Clinical Psychology Student, School of Psychology, The University of Auckland, New Zealand.

Associate Professor Clare M McCann: School of Psychology, The University of Auckland, New Zealand.

Professor Lynette Tippett: School of Psychology, The University of Auckland, New Zealand.

Associate Professor Gary Cheung: Department of Psychological Medicine, School of Medicine, The University of Auckland, New Zealand.


Associate Professor Clare M McCann: School of Psychology, The University of Auckland, New Zealand.

Correspondence email

Competing interests


1)       Douglass A, Young G, McMillan J. Mental Capacity: Updating New Zealand’s Law and Practice: A Toolkit for Assessing Capacity [Internet]. 2016 [cited 2023 Nov 5]. Available from:

2)       Staunton PJ, Chiarella M. Law for nurses and midwives. 7th ed. Sydney, Australia: Churchill Livingstone, 2013.

3)       Kane NB, Ruck Keene A, Owen GS, Kim SYH. Difficult Capacity Cases – The Experience of Liaison Psychiatrists. An Interview Study Across Three Jurisdictions. Front Psychiatry. 2022 Jul 11;13:946234. doi: 10.3389/fpsyt.2022.946234.

4)       Poppe C, Elger BS, Wangmo T, Trachsel M. Evaluation of decision-making capacity in patients with dementia: challenges and recommendations from a secondary analysis of qualitative interviews. BMC Med Ethics. 2020;21(1):55. doi: 10.1186/s12910-020-00498-y.

5)       Davidson G, Brophy L, Campbell J, et al. An international comparison of legal frameworks for supported and substitute decision-making in mental health services. Int J Law Psychiatry. 2016;44:30-40.

6)       Aldous K, Tolmie R, Worrall L, Ferguson A. Speech-language pathologists’ contribution to the assessment of decision-making capacity in aphasia: a survey of common practices. Int J Speech Lang Pathol. 2014 Jun;16(3):231-41. doi: 10.3109/17549507.2013.871751.

7)       Watson J. Assumptions of Decision-Making Capacity: The Role Supporter Attitudes Play in the Realisation of Article 12 for People with Severe or Profound Intellectual Disability. Laws. 2016 Feb 19;5(1):6.

8)       Parker M. Patient competence and professional incompetence: disagreements in capacity assessments in one Australian jurisdiction, and their educational implications. Journal of Law and Medicine. 2008 Aug 1;16(1):25-35.

9)       Alam A, Barton C, Prathivadi P, Mazza D. Advance care planning in dementia: a qualitative study of Australian general practitioners. Aust J Prim Health. 2022 Feb;28(1):69-75. doi: 10.1071/PY20307.

10)    Connolly J, Peisah C. Waiting for guardianship in a public hospital geriatric inpatient unit: a mixed methods observational case series. Intern Med J. 2023 Aug;53(8):1339-46. doi: 10.1111/imj.15916.

11)    Lamont S, Stewart C, Chiarella M. Capacity and consent: Knowledge and practice of legal and healthcare standards. Nurs Ethics. 2019;26(1):71-83. doi: 10.1177/0969733016687162.

12)    Young G, Douglass A, Davison L. What do doctors know about assessing decision-making capacity? N Z Med J. 2018 Mar 9;131(1471):58-71.  

13)    Vara A, Young G, Douglass A, et al. General practitioners and decision-making capacity assessment: the experiences and educational needs of New Zealand general practitioners. Fam Pract. 2020 Sep 5;37(4):535-540. doi: 10.1093/fampra/cmaa022.

14)    Kiriaev O, Chacko E, Jurgens JD, et al. Should capacity assessments be performed routinely prior to discussing advance care planning with older people?. Int Psychogeriatr. 2018 Aug;30(8):1243-50. doi: 10.1017/S1041610217002836.

15)    Astell H, Lee JH, Sankaran S. Review of capacity assessments and recommendations for examining capacity. N Z Med J. 2013 Sep 27;126(1383):38-48.

16)    Douglass A, Young G, McMillan J. Assessment of Mental Capacity: A New Zealand Guide for Doctors and Lawyers. Wellington, New Zealand: Victoria University of Wellington Press; 2020. Chapter 13, Guidance for Health Practitioners; p. 395.

17)    Te Kaunihera Tapuhi o Aotearoa – Nursing Council of New Zealand. Mātanga Tapuhi – Nurse Practitioner [Internet]. [cited 2023 Oct 10]. Available from:

18)    Cunningham KL. Neuropsychological assessment of medico-legal capacity in the New Zealand context. Neuropsychological Formulation: A clinical Casebook. 2016:89-116.

19)    Matus J, Mickan S, Noble C. Developing occupational therapists’ capabilities for decision-making capacity assessments: how does a support role facilitate workplace learning? Perspectives on Medical Education. 2020 Apr;9:74-82.

20)   Mental Capacity Act 2005 (UK).

21)    Elo S, Kyngäs H. The qualitative content analysis process. J Adv Nurs. 2008;62(1):107-115. doi: 10.1111/j.1365-2648.2007.04569.x.

22)    Darzins PJ, Molloy WD, Strang D. Who Can Decide? The six step capacity assessment process. Australia: Memory Australia Press, South Australia; 2000. p. 151.

23)    Young G. How to assess a patient’s competence. New Ethicals Journal. 2004;41-45.

24)    Grisso T, Appelbaum PS, Hill-Fotouhi C. The MacCAT-T: a clinical tool to assess patients' capacities to make treatment decisions. Psychiatr Serv. 1997 Nov;48(11):1415-9. doi: 10.1176/ps.48.11.1415. 

25)    United Nations. Article 12 – Equal recognition before the law [Internet]. [cited 2023 Nov 10]. Available from:

26)    Hickling N, McCann CM, Tippett L, Cheung G. Exploring training, involvement and confidence: a study of healthcare professionals in decision-making capacity assessments. N Z Med J. 2024 Apr 12;137(1593):31-44. doi: 10.26635/6965.6299.

27)    Purser K, Magner ES, Madison J. A therapeutic approach to assessing legal capacity in Australia. Int J Law Psychiatry. 2015 Jan-Feb;38:18-28. doi: 10.1016/j.ijlp.2015.01.003.

28)    Mooney N, McCann CM, Tippett L, Cheung G. Decision-making capacity assessments in New Zealand and Australia: a systematised review. Psychiatr Psychol Law. 2023:1-26.

29)    Cassidy H, Sims A, Every-Palmer S. Psychiatrists’ views on the New Zealand End of Life Choice Act. Australas Psychiatry. 2022 Apr;30(2):254-261. doi: 10.1177/10398562221077889.

30)    Casey J, Macleod S. The assessment of competency and coercion in the End of Life Choice Act 2019. N Z Med J. 2021 Dec 17;134(1547):114-120.

31)    Te Aku Matua o te Ture – Law Commission. Review of adult decision-making capacity law [Internet]. [cited 2024 Mar 14]. Available from:

32)    interRAI New Zealand. interRAI New Zealand [Internet]. Wellington, New Zealand: Health New Zealand – Te Whatu Ora; [cited 2024 Mar 14]. Available from: