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
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.