Diagnostic reasoning by hospital pharmacists: assessment of attitudes, knowledge, and skills.

Background: Hospital pharmacists participate in activities that may be considered diagnostic. Two reasoning approaches to diagnosis have been described: non-analytic and analytic. Of the 6 analytic traditions, the probabilistic tradition has been shown to improve diagnostic accuracy and reduce unnecessary testing. To the authors' knowledge, pharmacists' attitudes toward having a diagnostic role and their diagnostic knowledge and skills have never been studied.

Objectives: To describe pharmacists' attitudes toward the role of diagnosis in pharmacotherapeutic problem-solving and to characterize the extent of pharmacists' knowledge and skills related to diagnostic literacy.

Methods: Pharmacists working within Lower Mainland Pharmacy Services (British Columbia) who spent at least 33% of their time in direct patient care were invited to participate in a prospective observational survey. The survey sought information about demographic characteristics and attitudes toward diagnosis. Diagnostic knowledge and skills were tested by means of 3 case scenarios. The analysis included simple descriptive statistics and inferential statistics to evaluate relationships between responses and experience and training.

Results: Of 266 pharmacists invited to participate, 94 responded. The attitudes section of the survey was completed by 90 pharmacists; of these, 80 (89%) agreed with the definition of "diagnosis" proposed in the survey, and 83 (92%) agreed that it is important for pharmacists to have diagnosis-related skills. Respondents preferred an analytic to a non-analytic approach to diagnostic decision-making. The probabilistic tradition was not the preferred method in any of the 3 cases. In evaluating 5 clinical scenarios that might require diagnostic skills, on average 84% of respondents agreed that they should be involved in assessing such problems. Respondents' knowledge of and ability to apply probabilistic diagnostic tools were highest for test sensitivity (average of 61% of respondents with the correct answers) and lower for test specificity (average of 48% with correct answers) and likelihood ratios (average of 39% with correct answers).

Conclusions: Respondents to this survey strongly believed that diagnostic skills were important for solving drug-related problems, but they demonstrated low levels of knowledge and ability to apply concepts of probabilistic diagnostic reasoning. Opportunities to expand pharmacists' knowledge of diagnostic reasoning exist, and the findings reported here indicate that pharmacists would consider such professional development valuable.