I believed that data saves lives

I Once Believed Data Would Save Lives is a personal and unsparing account a long struggle with digital health, told from the perspective of someone who has spent decades working at the intersection of medicine, technology, and policy. Drawing on her own biography, from early encounters with computing in the 1980s to leadership roles in national and European health data infrastructures, Sylvia Thun reflects on why digitalization in healthcare so often fails to deliver on its promises. The book traces the gap between technical possibility and institutional reality: brilliant standards that are ignored, successful European projects, and political decisions that prioritize compromise over coherence. Rather than celebrating technology for its own sake, this book insists on responsibility: responsibility for meaning, for interoperability, and for the people behind the data. Thun shows why artificial intelligence without standards is dangerous, why data spaces without shared semantics cannot scale, and why trust, not innovation is the scarcest resource in modern healthcare. At its core, this is not a book about technology. It is a book about people, power, governance, and the human cost of fragmented systems. It argues that digital health will only succeed if it serves those who are sick, supports those who care for them, and never forgets that behind every data point stands a human life.