Re-examining the effect of door-to-balloon delay on STEMI outcomes in the context of unmeasured confounders: a retrospective cohort study
View/ Open
Date
2019-12-27Author
Foo, Chee Yoong
Andrianopoulos, Nick
Brennan, Angela
Ajani, Andrew
Reid, Christopher M.
Duffy, Stephen J.
Clark, David J.
Reidpath, Daniel
Chaiyakunapruk, Nathorn
Metadata
Show full item recordCitation
Foo, C.Y., Andrianopoulos, N., Brennan, A., Ajani, A., Reid, C.M., Duffy, S.J., Clark, D.J., Reidpath, D.D. and Chaiyakunapruk, N. (2019) ‘Re-examining the effect of door-to-balloon delay on STEMI outcomes in the context of unmeasured confounders: a retrospective cohort study’, Scientific Reports, 9(1), p. 19978. Available at: https://doi.org/10.1038/s41598-019-56353-7.
Abstract
Literature studying the door-to-balloon time-outcome relation in coronary intervention is limited by the potential of residual biases from unobserved confounders. This study re-examines the time-outcome relation with further consideration of the unobserved factors and reports the population average effect. Adults with ST-elevation myocardial infarction admitted to one of the six registry participating hospitals in Australia were included in this study. The exposure variable was patient-level door-to-balloon time. Primary outcomes assessed included in-hospital and 30 days mortality. 4343 patients fulfilled the study criteria. 38.0% (1651) experienced a door-to-balloon delay of >90 minutes. The absolute risk differences for in-hospital and 30-day deaths between the two exposure subgroups with balanced covariates were 2.81 (95% CI 1.04, 4.58) and 3.37 (95% CI 1.49, 5.26) per 100 population. When unmeasured factors were taken into consideration, the risk difference were 20.7 (95% CI −2.6, 44.0) and 22.6 (95% CI −1.7, 47.0) per 100 population. Despite further adjustment of the observed and unobserved factors, this study suggests a directionally consistent linkage between longer door-to-balloon delay and higher risk of adverse outcomes at the population level. Greater uncertainties were observed when unmeasured factors were taken into consideration.