Nurse practitioner diagnostic reasoning : a thesis presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Nursing at Massey University, New Zealand

Thumbnail Image
Open Access Location
Journal Title
Journal ISSN
Volume Title
Massey University
The Author
Introduction: Nurse practitioners were introduced to increase patients’ access to healthcare, improve patient outcomes, and provide a sustainable solution to ongoing workforce shortages. They provide a diagnostic role previously delivered by doctors, however, their ability to perform this role has been challenged. Methodology: The study used a post-positivist mixed methods convergent parallel design to explore nurse practitioner diagnostic reasoning and compare it to that of registrars. Methods included a complex case scenario using think aloud protocol to determine diagnostic abilities, including identifying correct diagnoses, problems and actions; a previously validated intuitive/analytic reasoning instrument to identify diagnostic reasoning style; a maxims questionnaire to identify maxims used to guide diagnostic reasoning; and a demographic data sheet to identify variables influencing the results of the former. The study included 30 nurse practitioners and 16 registrars. An expert panel determined the correct diagnoses/problems and actions for the case scenario using a Delphi technique. Registrar data provided normative data and norm-referenced testing compared the nurse practitioner data to the normative data. Results: Nurse practitioners identified a mean of 10.30 (range=4-17, Mdn=10, mode=9, SD=3.09) correct diagnoses, problem and action items as identified by the expert panel whereas registrars identified a mean of 10.88 (range=6-21, Mdn=10, SD=3.88); there was no statistically significant difference between the two groups (U=238.5, z=-.04, p=.97). Nurse practitioners’ diagnostic reasoning reflected an analytic-intuitive style whereas registrars reflected an analytic style, however, this difference was not statistically significant, t(44)=1.91, p=.06. Diagnostic reasoning style was not related to diagnostic reasoning abilities in either the nurse practitioner (rs=-.14, n=30, p=.46) or registrar (rs=.03, n=16, p=.90) groups. There was no difference in how nurse practitioners and registrars employ maxims to guide their diagnostic reasoning, t(44)=-.89, p=.38. Maxims used to guide diagnostic reasoning were not related to diagnostic reasoning abilities in either the nurse practitioner (r=-.17, n=30, p=.37) or registrar (rs=-.08, n=16, p=.77) groups. Conclusion: Nurse practitioners’ diagnostic reasoning, although incorporating more System I processes than registrars, does not differ from that of registrars. This supports the nurse practitioner role as a sustainable solution firstly, to effectively meet the health needs of the New Zealand population and secondly, to address workforce shortages.
Nurse practitioners, Diagnostic reasoning, Diagnosis, Registrars