Forearmed is forewarned: A prospective intervention observational time-series study of patient empowerment for ultrasound-guided peripheral intravenous access.

OBJECTIVE: Ultrasound (US) is a valuable adjunct to improve the success rates of difficult peripheral intravenous cannula (PIVC) insertions but is usually clinician initiated. The present study assessed for any change in clinician practice resulting from interventions aimed at empowering patients to advocate for early use of US if they self-identified as having difficult PIVC access. METHODS: This was a prospective observational time-series study using a rapid quality improvement (RQI) framework. Three ED waiting room intervention strategies (printed media, video and wristband) were tested over three 2-week periods at a large teaching hospital. The impact of each intervention was assessed at eight time points during each intervention and compared to a pre-intervention baseline period using trend and time-series analysis. RESULTS: A total of 1611 PIVC insertions were surveyed over 42 time points. The proportion of US-guided PIVC insertions was highest during Intervention 3 (wristbands; 5.5%) but all proportions remained below baseline (6.5%). Trend analysis identified an increasing frequency of US use during Intervention 1 (printed media, P = 0.01). However, no statistically significant trends were observed within the periods. CONCLUSIONS: This is the first prospective study to assess the effect of various interventions to empower patients to self-identify as having difficult PIVC access and advocate for the use of US-guidance. The present study was indeterminate: no intervention tested in the present study noticeably influenced clinical practice, potentially attributable to the study design and confounding factors. This innovative study serves as a pilot for future research into patient empowerment, which is currently lacking in the literature.

How revealed preference theory can be explanatory.

The question of how to frame agential preferences in economics finds one caught between Scylla and Charybdis. If preferences are framed in as minimal and deflationary a manner as revealed preference theory recommends, the theory falls prey to objections about its predictiveness and explanatory power. Alternatively, if too many cognitive and causal intricacies are incorporated into the preference concept, revealed preference models will violate pragmatic norms of model construction, surrendering model simplicity and generality. This paper charts a middle course, arguing that the path to salvation lies through an understanding of revealed preference models as program explanations.

Distinctively mathematical explanation and the problem of directionality: A quasi-erotetic solution.

The increasing preponderance of opinion that some natural phenomena can be explained mathematically has inspired a search for a viable account of distinctively mathematical explanation. Among the desiderata for an adequate account is that it should solve the problem of directionality -the reversals of distinctively mathematical explanations should not count as members among the explanatory fold but any solution must also avoid the exclusion of genuine explanations. In what follows, I introduce and defend what I refer to as a quasi-erotetic solution which provides a remedy to the problem in the form of an additional necessary condition on explanation.