Massive German Study Will Mine a Decade of Psychiatric Records to Expose Diversity Gaps in Care

A sweeping new research project is set to ask one of the most uncomfortable questions in modern mental health care: does the treatment you receive in a psychiatric hospital depend on who you are? PSY-DIVER, a participatory mixed-methods study led by the LVR Institute for Research and Education in Cologne, has published its study protocol in BMC Psychiatry, laying out an ambitious three-year plan to determine how gender and other diversity-related factors shape the use, acceptance and effectiveness of psychiatric inpatient care in Germany. The project runs from 1 November 2025 to 31 October 2028 and is funded by the Innovation Committee of the Federal Joint Committee (G-BA), Germany, under funding number 01VSF25022, with the funding organization having no influence on the study design, data collection and analysis, decision to publish, or preparation of the manuscript.

The scale of the undertaking is what sets it apart. Psychiatric hospital care is inherently multimodal, typically combining pharmacotherapy, psychotherapy, social therapy, occupational therapy, exercise therapy and various forms of creative therapies. Whether a patient receives one of these interventions rather than another, and whether that intervention works as intended, may be shaped by a constellation of diversity-related factors including age, migration background, sexual orientation, religious beliefs and socioeconomic status. Yet, as the research team notes, the impact of such factors on psychiatric inpatient care processes and outcomes has never been comprehensively examined in German psychiatric hospitals. PSY-DIVER is designed to close that gap with an evidence base large enough to withstand scrutiny.

At the heart of the quantitative component lies an extraordinary data resource: routine data from the nine psychiatric hospitals of the LVR, the Rhineland Regional Council. The researchers will analyze approximately 500,000 inpatient and day-care clinic cases and 1.7 million outpatient cases spanning 2015 to 2024, with a planned extension to more recent retrospective data during the project period. This decade-long window allows the team to examine not just isolated treatment decisions but entire care trajectories, from admission through treatment allocation to discharge outcomes, across an extraordinarily diverse patient population treated in a real-world network of hospitals.

One of the study’s most technically interesting elements is how it plans to extract diversity-related information that structured hospital records simply do not capture. Structured routine data will be enriched by automated extraction of additional diversity-related variables from clinical free text using a rule-based natural language processing pipeline combined with locally hosted large language models operating in a secure local environment. This hybrid approach matters for two reasons. First, factors such as migration background, sexual orientation or religious beliefs are often documented only in narrative clinical notes rather than coded fields. Second, hosting the language models locally addresses the privacy concerns that inevitably arise when sensitive psychiatric records are processed computationally, keeping patient data inside the hospital network rather than sending it to external services.

The natural language processing pipeline represents a growing trend in health services research, where named entity recognition and related techniques are increasingly used to unlock the clinical richness buried in free text. By combining rule-based methods, which offer transparency and reproducibility, with large language models, which offer flexibility in understanding varied clinical phrasing, the PSY-DIVER team aims to construct diversity variables at a scale and granularity that manual chart review could never achieve across two million cases. The resulting dataset will allow statistical analyses of whether treatment allocation, treatment processes and treatment outcomes differ systematically across patient groups defined by gender and other diversity characteristics.

But numbers alone cannot explain why disparities might exist, and this is where the study’s qualitative and participatory design comes in. Primary data collection will include 31 semi-structured interviews with mental health service users, relatives and professionals, capturing lived experience and clinical perspective on how diversity-related factors play out in everyday ward life. These interviews will be followed by quantitative online surveys with approximately 300 service users, 100 relatives and 100 professionals, allowing the team to test whether themes emerging from the interviews hold across larger samples of stakeholders.

Participation is not merely a data collection strategy for PSY-DIVER; it is built into the project’s governance. The study includes participatory project governance featuring a co-creation workshop, and the team thanks the members of its participatory steering group and scientific advisory board, along with its project partner, the German Association for Psychiatry, Psychotherapy and Psychosomatics (DGPPN). This architecture reflects a broader movement in mental health research toward involving those with lived experience of psychiatric care not as subjects but as collaborators, on the premise that service users and relatives are best placed to identify the questions that matter and to interpret findings in ways that resonate with real clinical realities.

The final phase of the project translates integrated findings into actionable guidance. A two-round Delphi process will bring together approximately 40 professional experts and experts by experience in a structured consensus process to formulate recommendations for more diversity-sensitive psychiatric hospital care. The Delphi method, which iterates anonymous feedback rounds until participants converge on shared judgments, is well suited to contested topics where empirical evidence must be weighed alongside values and practical feasibility. By including experts by experience alongside clinicians in the consensus panel, the study ensures that its final recommendations reflect the perspectives of the people the recommendations are meant to serve.

The protocol has passed the formal safeguards expected of clinical research. The study was approved by the Ethics Committee of the North Rhine Medical Association under number 2026038, and data collection and analysis follow the Declaration of Helsinki. The trial was registered with the German Clinical Trials Register on April 30, 2026, under number DRKS00040088. The authors declare no competing interests, and the article is published open access under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, meaning the protocol itself is freely available to researchers, clinicians and patient advocates worldwide.

Why does this matter beyond Germany’s Rhineland? Psychiatric care systems across high-income countries face persistent questions about equity, and the intersectional interplay of gender, age, migration background, sexual orientation, religion and socioeconomic status is increasingly recognized as central to understanding why some patients receive effective care while others do not. PSY-DIVER’s combination of large-scale routine data, primary stakeholder data and a participatory consensus process offers a template that other health systems could adapt. If the study confirms that diversity-related factors are associated with differences in treatment allocation, treatment processes or outcomes, its recommendations could push psychiatric hospitals toward more equitable and diversity-sensitive services. If it finds no such associations, that too would be a valuable, publishable result. Either way, the project signals a maturing of health services research in psychiatry: an era in which the question is no longer whether diversity matters in mental health care, but precisely how, for whom, and what should be done about it. The study is led by a team including Sönke Johann Peters, Svenja Kratzke, Marwan Ahmed, Ana Staninska, Altina Aliu, Marisa Felicitas Flaspöler, Jürgen Zielasek, Carolin Schuster and corresponding author Euphrosyne Gouzoulis-Mayfrank, based at the LVR Institute for Research and Education in Cologne, with affiliations extending to the LVR Clinics Cologne, Heinrich Heine University Düsseldorf, Leuphana University Lüneburg and the University of Cologne.

Subject of Research: Diversity-related factors in psychiatric hospital care examined through a participatory mixed-methods study protocol

Article Title: Gender and other diversity-related factors in psychiatric hospital care: protocol for the participatory mixed-methods PSY-DIVER study

Article References: Peters, S. J., Kratzke, S., Ahmed, M., Staninska, A., Aliu, A., Flaspöler, M. F., Zielasek, J., Schuster, C., & Gouzoulis-Mayfrank, E. (2026). Gender and other diversity-related factors in psychiatric hospital care: protocol for the participatory mixed-methods PSY-DIVER study. BMC Psychiatry, 26(1), Article 744. https://doi.org/10.1186/s12888-026-08630-9

Image Credits: AI Generated

DOI: 10.1186/s12888-026-08630-9

Keywords: psychiatric hospital care, diversity, gender, intersectionality, mixed methods, participatory research, clinical routine data, natural language processing, health services research, Delphi, mental health, health equity