Latar Belakang: Pelayanan rumah sakit masih menghadapi tantangan dalam mendeteksi secara dini penurunan kondisi klinis pasien yang berisiko menimbulkan kegawatan dan mengancam keselamatan pasien. Early Warning System (EWS) dikembangkan sebagai alat bantu klinis berbasis skor fisiologis untuk mendukung deteksi dini dan respons klinis yang tepat waktu. RS Roemani Muhammadiyah Semarang telah mengimplementasikan EWS sejak tahun 2022, namun kejadian Code Blue dan angka kematian pasien rawat inap masih menunjukkan pola fluktuatif dan belum menurun secara konsisten. Selain itu, evaluasi menyeluruh terhadap pelaksanaan EWS belum pernah dilakukan, sehingga terdapat kesenjangan antara kebijakan, implementasi, dan luaran keselamatan pasien. Metode: Penelitian ini menggunakan desain kualitatif dengan pendekatan studi kasus, yang dianalisis menggunakan kerangka struktur–proses–outcome. Pengumpulan data dilakukan melalui wawancara mendalam dan focus group discussion (FGD) terhadap tenaga kesehatan yang terlibat langsung dalam implementasi EWS, dengan pemilihan informan secara purposive. Selain itu, dilakukan telaah dokumen terhadap rekam medis, formulir EWS, laporan kejadian Code Blue, serta dokumen kebijakan dan prosedur rumah sakit untuk menilai aspek struktur dan proses implementasi EWS serta luaran keselamatan pasien. Penelitian dilaksanakan di RS Roemani Muhammadiyah pada November–Desember 2025. Analisis data dilakukan secara tematik melalui proses pengodean, pengelompokan tema, dan interpretasi, dengan penerapan triangulasi sumber dan metode untuk menjaga keabsahan data. Hasil: Implementasi EWS belum berjalan optimal. Pada aspek struktur, dukungan kepemimpinan dan mekanisme pendukung klinis telah tersedia, namun masih terdapat keterbatasan pada kesiapan sistem dan sumber daya dalam mendukung pelaksanaan EWS secara konsisten. Pada aspek proses, kepatuhan terhadap dokumentasi dan eskalasi klinis masih bervariasi, serta komunikasi antarprofesi berbasis skor EWS belum terstandar dan masih bergantung pada inisiatif individu. Pada aspek outcome, kejadian Code Blue masih terjadi secara fluktuatif meskipun EWS telah diterapkan, disertai angka kematian pasien rawat inap yang belum menunjukkan penurunan yang konsisten. Kondisi ini mengindikasikan adanya kesenjangan antara implementasi EWS dan luaran keselamatan pasien. Kesimpulan: EWS di RS Roemani Muhammadiyah Semarang belum sepenuhnya berfungsi sebagai sistem deteksi dini yang efektif dalam mencegah kejadian Code Blue. Permasalahan utama tidak hanya terletak pada kepatuhan individu, tetapi juga pada aspek sistemik, termasuk tata kelola klinis, integrasi sistem, dan budaya komunikasi berbasis skor. Diperlukan pendekatan berpikir sistem yang menekankan penguatan struktur, standardisasi proses, serta monitoring dan evaluasi berkelanjutan untuk meningkatkan keselamatan pasien.

Background: Hospitals continue to face challenges in the early detection of clinical deterioration that may lead to acute emergencies and threaten patient safety. The Early Warning System (EWS) was developed as a physiology-based scoring tool to support early detection and timely clinical responses. RS Roemani Muhammadiyah has implemented EWS since 2022; however, Code Blue events and in-hospital mortality rates remain fluctuating and have not shown a consistent decline. Moreover, a comprehensive evaluation of EWS implementation has not yet been conducted, resulting in a gap between policy, practice, and patient safety outcomes. Methods: This study employed a qualitative case study design analyzed using the structure–process–outcome framework. Data were collected through in-depth interviews and focus group discussions (FGDs) with healthcare professionals directly involved in EWS implementation, selected purposively. Document reviews of medical records, EWS forms, Code Blue reports, and hospital policies and procedures were also conducted to assess structural and process aspects as well as patient safety outcomes. The study was conducted at RS Roemani Muhammadiyah from November to December 2025. Data were analyzed thematically through coding, theme development, and interpretation, with source and method triangulation applied to ensure trustworthiness. Results: EWS implementation was not yet optimal. In terms of structure, leadership support and basic clinical support mechanisms were in place; however, limitations remained in system readiness and resource capacity to ensure consistent implementation. Regarding process, compliance with documentation and clinical escalation varied, and interprofessional communication based on EWS scores was not standardized and often relied on individual initiative. In terms of outcomes, Code Blue events continued to occur in a fluctuating pattern despite EWS implementation, accompanied by in-hospital mortality rates that did not demonstrate a consistent decline. These findings indicate a gap between EWS implementation and patient safety outcomes. Conclusion: EWS at RS Roemani Muhammadiyah Semarang has not yet functioned optimally as an effective early detection system to prevent Code Blue events. The challenges identified are not limited to individual compliance but reflect broader systemic issues, including clinical governance, system integration, and a culture of score-based communication. A systems-thinking approach that emphasizes structural strengthening, process standardization, and continuous monitoring and evaluation is required to enhance patient safety.