Variation in prehospital ACS care within a single city: a bicentric observational study (MONAH-1 subgroup analysis).

MD1 showed substantially higher documented rates of 12-lead ECG acquisition compared to MD2 in prehospital ACS care.

• 12-lead ECG documentation rate was 76.9% at MD1 versus 43.5% at MD2
• Adjusted odds ratio of 4.24 (95% CI 3.36–5.35) favoring MD1
• Total sample included 1,438 emergency physician interventions (MD1: n=661; MD2: n=777)
• Analysis adjusted for age and gender only, described as 'partially adjusted exploratory models'

ASA (aspirin) administration was documented more frequently at MD1 than at MD2.

• ASA administration rate was 91.4% at MD1 versus 70.9% at MD2
• Adjusted odds ratio of 4.38 (95% CI 3.19–6.00) favoring MD1
• Study period covered prehospital physician missions with typical ACS diagnoses from 2014 to 2018 in Magdeburg
• MD1 comprised one EMS physician base; MD2 comprised two EMS physician bases

Heparin administration was documented more frequently at MD1 than at MD2.

• Heparin administration rate was 92.6% at MD1 versus 68.0% at MD2
• Adjusted odds ratio of 5.86 (95% CI 4.21–8.16) favoring MD1
• This was the largest adjusted odds ratio among the process indicators examined

In the indication-positive subgroup with documented pain scores ≥4, morphine was documented more often at MD1 than at MD2.

• Morphine documentation rate was 70.6% at MD1 versus 54.5% at MD2 in the VAS ≥4 subgroup
• Adjusted odds ratio of 2.67 (95% CI 2.04–3.50) in the exploratory adjusted model
• The exploratory adjusted morphine model was based on missions with documented pain assessment
• Authors note this is a descriptive indication-positive subgroup analysis

No significant differences were found between MD1 and MD2 for indication-based nitroglycerin and oxygen administration.

• Nitroglycerin and oxygen administration rates did not differ significantly between the two provider structures
• These were among the selected prehospital ACS process indicators examined
• This contrasts with the significant differences observed for ECG, ASA, heparin, and morphine

Prehospital dwell time was significantly longer at MD1 compared to MD2.

• Median prehospital dwell time was 34 minutes at MD1 versus 29 minutes at MD2
• Difference was statistically significant (p < 0.001)
• Authors note 'the possibility of reverse causation for dwell time' as a limitation precluding causal inference
• Longer dwell time at the site with higher process indicator documentation rates raises the question of whether more interventions extended scene time or whether more complex patients were attended

The study used a retrospective, diagnosis-targeted case retrieval method from archived protocols, which introduced notable methodological limitations.

• Case retrieval was diagnosis-targeted from archived protocols rather than based on a prospectively maintained screening registry
• A full flow diagram of all EMS missions could not be reconstructed reliably
• Endpoint-specific denominators are reported in text and tables rather than a unified denominator
• Multivariable analyses were adjusted for age and gender only, described as 'partially adjusted exploratory models'
• Retrospective design, heterogeneous documentation formats, and limited case-mix adjustment preclude causal inference or conclusions about patient benefit

The study was conducted as a prespecified intra-urban subgroup analysis of the larger MONAH-1 retrospective bicentric observational study.

• All prehospital physician missions with typical ACS diagnoses in Magdeburg between 2014 and 2018 were analysed
• The subgroup compared one EMS physician base (MD1) with two EMS physician bases (MD2) within the same municipal EMS system
• The study was registered retrospectively in the German Clinical Trials Register (DRKS00036944) on 27 August 2025
• Authors characterize findings as 'hypothesis-generating and primarily relevant for local quality assurance and prospective validation'