Methodological approaches to measuring the incidence of unplanned emergency department presentations by cancer patients receiving systemic anti-cancer therapy: a systematic review.

<bold>Background: </bold>The need to mitigate the volume of unplanned emergency department (ED) presentations is a priority for health systems globally. Current evidence on the incidence and risk factors associated with unplanned ED presentations is unclear because of substantial heterogeneity in methods reporting on this issue. The aim of this review was to examine the methodological approaches to measure the incidence of unplanned ED presentations by patients receiving systemic anti-cancer therapy in order to determine the strength of evidence and to inform future research.<bold>Methods: </bold>An electronic search of Medline, Embase, CINAHL, and Cochrane was undertaken. Papers published in English language between 2000 and 2019, and papers that included patients receiving systemic anti-cancer therapy as the denominator during the study period were included. Studies were eligible if they were analytical observational studies. Data relating to the methods used to measure the incidence of ED presentations by patients receiving systemic anti-cancer therapy were extracted and assessed for methodological rigor. Findings are reported in accordance with the Synthesis Without Meta-Analysis (SWiM) guideline.<bold>Results: </bold>Twenty-one articles met the inclusion criteria: 20 cohort studies, and one cross-sectional study. Overall risk of bias was moderate. There was substantial methodological and clinical heterogeneity in the papers included. Methodological rigor varied based on the description of methods such as the period of observation, loss to follow-up, reason for ED presentation and statistical methods to control for time varying events and potential confounders.<bold>Conclusions: </bold>There is considerable diversity in the population and methods used in studies that measure the incidence of unplanned ED presentations by patients receiving systemic anti-cancer therapy. Recommendations to support the development of robust evidence include enrolling participants at diagnosis or initiation of treatment, providing adequate description of regular care to support patients who experience toxicities, reporting reasons for and characteristics of participants who are lost to follow-up throughout the study period, clearly defining the outcome including the observation and follow-up period, and reporting crude numbers of ED presentations and the number of at-risk days to account for variation in the length of treatment protocols. [ABSTRACT FROM AUTHOR]