Insurance Claims Data Emerges as a Cornerstone of Swiss Health Research

Every time a Swiss patient visits a doctor, fills a prescription, or is admitted to a hospital, an electronic trace is generated somewhere in the machinery of the country’s health insurance system. Those traces, known collectively as claims data, have quietly become one of the most powerful tools available to researchers studying how health care is actually delivered and paid for. A new scoping review published in BMC Health Services Research has now mapped, for the first time in a comprehensive way, just how far this transformation has gone. Led by Mélanie Lötscher-Stamm and colleagues at the ZHAW Zurich University of Applied Sciences, the study documents a twenty-five-year arc in which claims data evolved from a rarely tapped resource into a mainstream pillar of Swiss health research, growing twenty-two-fold in scientific output between the turn of the millennium and today.

The scale of the growth is striking. Between 2000 and 2004, the review identified only five publications using Swiss claims data. By the period from 2020 to 2024, that number had climbed to 110 publications, an increase by a factor of 22. In total, 256 individual sources met the review’s inclusion criteria out of 1,922 records initially identified. The trajectory reflects both a rising demand for real-world evidence and a gradual loosening of the technical and legal barriers that once made insurance records difficult to access for scientific purposes. In a country like Switzerland, which lacks the centralized administrative health databases found in nations with national public health care systems, claims data have filled a gap that would otherwise leave researchers largely blind to patterns of care outside clinical trials.

The methodology behind the review was deliberately rigorous. The research team searched five bibliographic databases, namely Medline, Scopus, CINAHL, Business Source Premier, and EconLit, and supplemented these with a manual search of the gray literature, capturing reports and studies that never appeared in peer-reviewed journals. Screening was carried out independently by two researchers using the CADIMA platform, a web-based tool designed to support systematic and scoping reviews, and data extraction proceeded through a standardized charting form built in REDCap, a secure electronic data capture system. Eligibility criteria covered source language, publication type, the health-related nature of the research, and, crucially, the use of Swiss claims data. The review followed the PRISMA-ScR extension for scoping reviews, ensuring transparent reporting of how records were identified, screened, and included.

What emerges from the analysis is a detailed portrait of who uses claims data and how. Health services research dominates the field, accounting for 42.6 percent of the included studies, followed by health economics at 29.7 percent. This distribution makes intuitive sense: claims records capture exactly the variables that these disciplines prize, including diagnoses coded for billing, procedures performed, drugs dispensed, durations of hospital stays, and the costs attached to each encounter. For economists tracking the drivers of health care expenditure or for services researchers evaluating pathways of care, the billing record is not merely an administrative artifact but a longitudinal window into the behavior of patients, providers, and insurers across the entire country.

The technical character of the data itself helps explain its appeal. In 74.2 percent of the reviewed studies, claims data served as the main data source, and in 81.6 percent of studies, patient-level data were used, meaning researchers could follow individuals rather than working with aggregated statistics. Perhaps most tellingly, 44.9 percent of studies enriched their claims data with additional sources, linking insurance records to survey responses, clinical registries, or other administrative datasets. This practice of record linkage is where claims data reveal their greatest scientific value, because billing records alone say little about outcomes, lifestyle, or patient experience. By joining claims to other data, researchers can construct far richer pictures of disease trajectories and treatment effectiveness than either source could provide alone.

Access arrangements, however, reveal a structural peculiarity of the Swiss system. In 78.9 percent of studies, researchers obtained claims data directly from health insurers, and among those, 64.9 percent received their data from a single company, the Helsana Group. Switzerland’s mandatory health insurance is provided by competing private insurers, and there is no single national repository that pools billing records across all of them. As a result, the practical gateway to Swiss claims data has often run through one dominant insurer, which shapes what research is possible. Studies based on a single insurer’s portfolio inherit that insurer’s market share and client demographics, a constraint that recurs throughout the literature and that the review identifies as one of the field’s most persistent limitations.

Indeed, the limitations catalogued by the reviewed studies form a consistent pattern. The most frequently mentioned shortcoming, cited in 30.9 percent of studies, was the lack of diagnostic information, since claims records contain billing codes rather than the full clinical detail found in medical charts, laboratory results, or imaging. Limited population coverage, a consequence of relying on single-insurer data, was flagged in 28.1 percent of studies. Missing invoices paid directly by patients, which escape the insurance system entirely, were noted in 22.7 percent. Each of these gaps introduces potential bias: analyses may undercount certain conditions, miss segments of the population, or overlook out-of-pocket care. For researchers, the message is that claims data are powerful but partial, and that conclusions drawn from them must be interpreted with an explicit understanding of what the billing process does and does not record.

Another notable finding concerns where the research is published. Among the included studies that appeared in journals, 90.0 percent were published in international outlets rather than domestic ones. This suggests that Swiss claims data research has matured into a field of global relevance, contributing to international debates on health care utilization, cost containment, and comparative health system performance. It also signals that the methodological lessons learned in Switzerland, a decentralized system with competing insurers, may be transferable to other countries grappling with fragmented data landscapes. The review’s authors, who also include Rebecca Duewell, Andreas Kohler, Xavier Schärer, Michael Stucki, and Simon Wieser, position their work as a foundation for future efforts, noting that ongoing initiatives to address the identified limitations may push the boundaries of health-related research in Switzerland.

The broader significance of the review lies in what it says about the future of real-world evidence. Health systems everywhere are under pressure to demonstrate value, and the gold standard of randomized controlled trials cannot answer every question about how care performs in routine practice. Claims data, with their population scale, longitudinal depth, and relative affordability, offer a complementary evidence stream, provided their blind spots are acknowledged and mitigated. The Swiss experience documented in this review shows both the promise and the peril: a data source that multiplied twenty-two-fold in research use over a quarter century, yet one still constrained by missing diagnostics, fragmented coverage, and dependence on individual insurers. As Switzerland develops new data infrastructures and linkage capabilities, the trajectory mapped by Lötscher-Stamm and her colleagues suggests that the country’s insurance records will only grow in importance, transforming routine billing paperwork into an increasingly refined instrument for understanding and improving health care.

Subject of Research: From claim to evidence: a scoping review of the use of claims data for health research in Switzerland

Article Title: From claim to evidence: a scoping review of the use of claims data for health research in Switzerland

Article References: Lötscher-Stamm, M., Duewell, R., Kohler, A., Schärer, X., Stucki, M., & Wieser, S. (2026). From claim to evidence: a scoping review of the use of claims data for health research in Switzerland. BMC Health Services Research. https://doi.org/10.1186/s12913-026-15806-2

Image Credits: AI Generated

DOI: 10.1186/s12913-026-15806-2

Keywords: claim, evidence, scoping, review, claims, data, health, research, Switzerland, scientific research