According to the World Health Organization, more than 770 million people worldwide have been infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), with approximately 6.9 million deaths [1]. While symptoms often subside within 14 days, many patients continue to have symptoms after the acute illness [2,3]. The generally used term ‘long COVID,’ medically described as post-COVID-19 condition (PCC) is defined as the presence of symptoms that persist or newly develop three months after a SARS-CoV-2 infection and last for at least two months without an alternative explanation [4]. The symptoms experienced by patients with PCC are highly diverse and reflect the multifaceted nature of the condition. These symptoms can affect multiple systems of the body, further highlighting the complexity of the condition [3,5,6]. However, there are certain symptoms that occur more frequently. These include fatigue, myalgia, neurological symptoms such as cognitive impairment, loss of smell and taste, as well as headaches, mental health issues, including depression and anxiety, and cardiopulmonary symptoms like dyspnea, chest pain, and palpitations [5,7-11].

The broad range and duration of these symptoms, combined with the diverse nature and unpredictability of PCC, often lead to increased and prolonged health care utilization in both ambulatory and hospital settings, as demonstrated in several studies [12-15]. The increase in utilization has a major impact on the health care system, which is faced with rising costs and increasing demand for specialized treatment [14,16,17]. A study from the United States showed that SARS-CoV-2 infection was associated with an overall 4% increase in health care utilization within six months of infection, primarily driven by virtual contacts and emergency department visits [18]. Specifically for the ambulatory setting, recent studies on PCC health care utilization have mainly focused on treatment by specialists or consultation with primary care physicians. However, many of these studies are limited by follow-up periods of less than six months [5,8,10,11]. At the same time, international research is increasingly addressing potential barriers to care and patient experiences in accessing PCC-related health care services. These studies indicate that access to care is often limited by long waiting times, a shortage of specialists, and a lack of specialized treatment services. They also underscore the urgent need for patient-centered approaches to improve care for those affected [19-23].

Evidence on long-term health care utilization, particularly with respect to different types of physician services, remains limited. Gaining a more comprehensive understanding of health care utilization and the specific needs of patients following a SARS-CoV-2 infection is essential for policymaking and clinical management of affected patients.

To improve the understanding of both objective care pathways and subjective patient experiences, claims data derived from the routine records of the Bavarian Association of Statutory Health Insurance Physicians (KVB) will be analyzed, and qualitative interviews and a focus group will be conducted to examine the individual care experiences of people affected by PCC. The aim of the study is to systematically examine health care utilization among patients after an acute SARS-CoV-2 infection, in Bavaria, Germany, with a particular focus on PCC. The study combines claims data analysis with qualitative interviews to improve the understanding of objective care pathways and patients’ subjective experiences within the health care system.

To ensure a high scientific standard and transparency, the reporting of this study protocol and the study results will adhere to the following guidelines: the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guideline and the Consolidated criteria for reporting qualitative research (COREQ) Checklist [24-26]. The study is registered in the German Clinical Trials Register (registration number DRKS00038446).

The study was funded by the German Federal Joint Committee Innovation Fund in October 2024 and is progressing according to the planned timeline, with data collection and analysis set to commence thereafter to generate meaningful results. Subproject 1: Statutory health insurance claims data covering the period from 2019 to 2022 were provided by the KVB. The first access to the routine data was in March 2025, with corrections made in April 2025. Analysis of the routine data began in July 2025 with quality control and descriptive analyses, with the first results expected by May 2026. Further analyses will be conducted until April 2027. Subproject 2: The recruitment of participants for the qualitative interviews and focus groups began in May 2025, and data collection and recruitment are expected to be finished by June 2026. As of manuscript submission, study preparation and ethics approvals have been completed, and 14 participants have been recruited for the qualitative interviews. First results of the qualitative interviews and focus group are expected in August 2026. The synthesis of the results and the development of recommendations are expected to be finished in August 2027.

This mixed-methods study will contribute to deepening and expanding the current state of research by combining systematic evidence synthesis, qualitative and quantitative approaches of subjective care experiences and objective care pathways of patients with PCC. The mixed-methods design was chosen to capture individual experiences of care that can be triangulated with the results of the routine data analysis, interpreted and embedded in the current state of research. The combination of different methods is a strength of this study, as it offers the opportunity to gain a deeper and more comprehensive understanding of ambulatory care practices for PCC. While there may be different descriptions or explanations, they complement each other and contribute to a broader picture [27,36].

It is expected that patients with PCC will show increased health care utilization. The wide range of symptoms observed in this population, combined with the heterogeneity of available health care services, presents a major challenge in identifying appropriate care pathways. Therefore, this study determines, in comparison with control cohorts, which services were utilized and what outcomes were achieved. In addition, it seeks to identify approaches that could improve care delivery. While the expected findings are currently limited to COVID-19 and PCC, they may offer valuable insights for managing other post-infectious conditions and for supporting patients with still persistent PCC symptoms. This could lead to a more efficient use of resources in the ambulatory sector and support earlier improvements in patients’ health. Through the integration of the systematic review, as well as subjective and objective care pathways and experiences, the study offers a substantial opportunity for an improved care provision.

As for all studies, some limitations need to be considered. First, in analyzing claims data, it must be acknowledged that clinical information is only available to a limited extent, as coding is primarily based on billing-related aspects. This can result in inaccuracies, particularly regarding ICD codes, due to the lack of mandatory coding standards, especially in general practice settings [37]. In addition, the dataset is limited to the region of Bavaria, which may introduce regional bias in observed health care utilization patterns. Temporal inaccuracies can also occur, as the recorded dates often reflect billing processes rather than the exact time of care provision [38].

Second, for the qualitative study, interviews capture subjective perspectives rather than objective realities. Recruitment via support groups and snowball sampling may lead to an overrepresentation of individuals who are more engaged or better connected within patient networks. Individuals with PCC who are less socially connected or socioeconomically disadvantaged may be underrepresented. While qualitative research does not aim for statistical representativeness, it seeks to provide in-depth insights into experiences, perceptions, and contextual factors [39]. The interview setting may introduce selectivity or artificiality, especially with personal topics like health. Moreover, the interpretative nature of the method involves a degree of subjectivity, and inherent trade-offs, such as between narrative depth and comparability which must be carefully managed [40]. The methodology for preparing and conducting the interviews will therefore be carefully designed to ensure consistency, taking into account all aspects of the research to enhance both the validity of the interviews and the overall understanding of the study. Furthermore, the focus only on patients in the Munich region may not fully capture health care experiences and developments in other geographical or more rural areas. A potential bias may also arise among focus group participants, as individuals involved in such networks may be more proactive or reflective about their situation.

Based on the expected results, this study is intended to provide concrete evidence for decision-makers in health care policy, particularly with regard to the future planning and organization of care structures. The more systematic inclusion of the patient-centered perspective can improve the relevance and effectiveness of future care concepts.