Abstract
International guidelines recommend percutaneous coronary intervention (PCI) to treat acute myocardial infarction (AMI) if PCI can be performed within two hours. PCI is a centralized treatment, and therefore a common trade-off is whether to send AMI patients directly to a hospital that performs PCI, or postponing a potential PCI-treatment by first receiving acute treatment at a non-PCI-hospital. In this paper, we estimate the effect of sending patients directly to a PCI-hospital on AMI mortality. Since the underlying health of patients may affect both hospital assignment and mortality, estimates from traditional multivariate risk adjustment models are likely biased. We therefore apply an instrumental variable (IV) model using the historical municipal share that is sent directly to a PCI-hospital as an instrument for being sent directly to a PCI-hospital. Our results disclose that patients sent directly to a PCI-hospital are younger and have fewer comorbidities than patients who are first sent to a non-PCI-hospital. Our IV results suggest that those initially sent to PCI-hospitals have 4.8 percentage points decrease (95% CI (-18.1)-8.5) in mortality after one month compared to those initially sent to non-PCI-hospitals. However, the estimates are too imprecise to conclude that health personnel should change their practice.
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
This paper has received funding from the Research Council of Norway (grant \#256678 and \#256570), as well as our respective employers.
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
Permission to use patient data from Norwegian Regional Ethics Committee was given(#2017/373).
I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.
Yes
I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).
Yes
I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.
Yes
Data Availability
The datasets that support the findings of this study contain sensitive information and are not publicly available due to privacy laws. Individual-level data for research are generally available within Norway upon application conforming with strict regulations and procedures.