Mixed-methods process evaluation of a respiratory-culture diagnostic stewardship intervention

Abstract

Objective: To conduct a process evaluation of a respiratory culture diagnostic stewardship intervention. Design: Mixed-methods study. Setting: Tertiary-care pediatric intensive care unit (PICU). Participants: Critical care, infectious diseases, and pulmonary attending physicians and fellows; PICU nurse practitioners and hospitalist physicians; pediatric residents; and PICU nurses and respiratory therapists. Methods: This mixed-methods study was conducted concurrently with a diagnostic stewardship intervention to reduce the inappropriate collection of respiratory cultures in mechanically ventilated children. We quantified baseline respiratory culture utilization and indications for ordering using quantitative methods. Semistructured interviews informed by these data and the Consolidated Framework for Implementation Research (CFIR) were then performed, recorded, transcribed, and coded to identify salient themes. Finally, themes identified in these interviews were used to create a cross-sectional survey. Results: The number of cultures collected per day of service varied between attending physicians (range, 2.2–27 cultures per 100 days). In total, 14 interviews were performed, and 87 clinicians completed the survey (response rate, 47%) and 77 nurses or respiratory therapists completed the survey (response rate, 17%). Clinicians varied in their stated practices regarding culture ordering, and these differences both clustered by specialty and were associated with perceived utility of the respiratory culture. Furthermore, group “default” practices, fear, and hierarchy were drivers of culture orders. Barriers to standardization included fear of a missed diagnosis and tension between practice standardization and individual decision making. Conclusions: We identified significant variation in utilization and perceptions of respiratory cultures as well as several key barriers to implementation of this diagnostic test stewardship intervention.

Repeat Tracheal Aspirate Cultures: A Port in the Storm or a Sinking Ship?*

“…When faced with one of these scenarios, clinicians may be unaware that a TAC has recently been collected or believe that a repeat culture should be obtained irrespective of the time since last culture. Local “testing etiquette” may also drive some behavior around collecting TACs, such that actual or perceived expectations around whether or not to perform a test supersede evidence-based individual decision-making (12). A fear of “missing something” in a critically ill patient is a pervasive driver of decision-making and may contribute to culture overuse in the PICU (12, 13).…”

“…Local “testing etiquette” may also drive some behavior around collecting TACs, such that actual or perceived expectations around whether or not to perform a test supersede evidence-based individual decision-making (12). A fear of “missing something” in a critically ill patient is a pervasive driver of decision-making and may contribute to culture overuse in the PICU (12, 13). In the case of repeat TACs specifically, this fear is arguably unfounded in most cases, given that the diagnostic information provided in the repeat culture is already, or will soon be available from the initial culture.…”

“…Beyond patient factors, emerging literature suggests that multilevel contextual factors, including individual values, preferences, and local culture influence clinician decision-making around microbiologic diagnostic testing (11)(12)(13). Though challenging to apply directly to the present study as the reasons for TAC collection were not reported, prior work suggests that performing cultures in certain scenarios in the PICU is "reflexive, " including collecting a TAC in the setting of fever or changes in airway secretions (12)(13)(14). When faced with one of these scenarios, clinicians may be unaware that a TAC has recently been collected or believe that a repeat culture should be obtained irrespective of the time since last culture.…”

So tell me… does this tracheal aspirate culture indicate “infection” or “colonization”?

“…In the preanalytic period, a clinical decision support algorithm can help to optimize respiratory test use for the patients it is most likely to benefit 9 . However, patient medical complexity and clinician autonomy may be relevant barriers to this type of intervention 10 . During the analytic period, screening methods can be used to ensure that only acceptable specimens are tested, improving the clinical utility of the results and reducing specimen volume and associated costs 11,12 .…”

“…9 However, patient medical complexity and clinician autonomy may be relevant barriers to this type of intervention. 10 During the analytic period, screening methods can be used to ensure that only acceptable specimens are tested, improving the clinical utility of the results and reducing specimen volume and associated costs. 11,12 Finally, in the postanalytic period, adhering to reporting guidelines or modifying microbiology reports from respiratory cultures may help reduce unnecessary antibiotic prescribing.…”