Mixed-method analysis of screening for Strongyloides stercoralis prior to immunosuppression: a problem of limited bandwidth?

BACKGROUND: Guidelines recommend screening for strongyloidiasis prior to immunosuppression in those at epidemiological risk, as hyperinfection following immunosuppression is often fatal. The uptake of this recommendation is unknown and we aimed to explore this in our setting. AIMS: To determine the proportion of adult patients at epidemiological risk for strongyloidiasis who were screened prior to immunosuppression at the Royal Melbourne Hospital, and to explore the factors that influenced clinicians' decision to screen for strongyloidiasis prior to immunosuppression. METHODS: This study used a mixed-methods approach. First, a 12-month (1 January 2018 to 1 January 2019) retrospective observational study was used to quantify the proportion of those at epidemiological risk who were screened prior to immunosuppression, while also identifying variables that were positively or negatively associated with screening. Second, clinicians from relevant specialties were recruited for focus group sessions to explore factors that influenced their decision to screen according to an interpretivist framework. RESULTS: A total of 230 newly immunosuppressed patients at epidemiological risk of strongyloidiasis were identified, of whom 87 (37.8%) were screened prior to immunosuppression. In multivariate analysis, older patients, outpatients and people from non-English-speaking backgrounds were significantly less likely to be screened. In focus groups, several barriers and enablers to screening were identified. Notably, clinicians reported that a major barrier was the cognitive load required to clinically reason about this uncommon disease, in addition to other priorities. CONCLUSIONS: We identified many missed opportunities to screen patients at risk of hyperinfection, particularly those most vulnerable. To improve screening, this study highlights the importance of reducing cognitive load by using decision-support tools, which may facilitate screening in vulnerable patients and in time-constrained settings.