Protocol of the digital long COVID study: A single-center, registry-based, feasibility and clinical evaluation study to investigate a 12-week digital intervention program for people affected by post-COVID-19 condition Stefan Rohner, Rebekka Schnepper, Andrea Meienberg, Katrin Bopp, Michael Mayr, Gunther Meinlschmidt, Rainer Schaefert Plos One, 2026 Up to 400 million individuals globally are estimated to experience persistent symptoms, including fatigue, muscle pain, and brain fog, following severe acute respiratory syndrome coronavirus type 2 infection. These persistent symptoms are referred to as Post-COVID-19 condition if they last for more than 12 weeks after infection and persist for at least 8 weeks and often causing significant distress and burden. The underlying pathological mechanisms have not yet been fully elucidated. Due to the heterogeneity of the disease a multifactorial origin is highly likely. Overall, evidence on optimal management is limited, and no medication has yet proven to be effective. Current symptom management and treatment guidelines suggest a biopsychosocial perspective and emphasize multidisciplinary approaches. Comprehensive interventions, adequate treatment access, and appropriate resources remain insufficiently available and implementing digital interventions might help mitigate these limitations. This protocol details a single-site feasibility and clinical evaluation study aiming to bridge this gap. By implementing an exploratory, open-label, digital interventional approach this study investigates the feasibility and efficacy of a 12-week program delivered by a cloud-based application. The program consists of 13 modules encompassing a wide range of topics (e.g., energy management, self-care, stress management) and includes informational (e.g., psychoeducational content) and interactive (e.g., exercises, self-reflection diaries) components. Customization options align the material with participant needs. A dedicated feedback section in each module captures feedback regarding usability and feasibility. Participants are monitored and checked for adherence throughout the study. The primary outcome is the post-intervention change in functional capacity measured by the World Health Organization Disability Assessment Schedule 2.0. All participants provide written informed consent. Key results from the study will be published in peer-reviewed journals.
Basel Long COVID Cohort Study (BALCoS): protocol of a prospective cohort study Stefan Rohner, Rebekka Schnepper, Gunther Meinlschmidt, Rainer Schaefert, Michael Mayr, Katrin Bopp, Andrea Meienberg BMJ Open, 2025 Introduction The recent pandemic caused by SARS-CoV-2 had a profound global impact. While many individuals recovered from COVID-19, some developed long-lasting symptoms that significantly disrupted daily life. The WHO defines this condition as post-COVID-19 condition (PCC). Common symptoms include fatigue, dyspnoea, sleep disturbances and cognitive difficulties. Increasing evidence suggests that PCC is a multifactorial condition, shaped not only by biomedical but also psychological and social factors. This article presents the protocol of the Basel Long COVID Cohort Study (BALCoS), which aims to improve understanding of PCC by capturing clinical, functional and psychosocial aspects through repeated assessments over the course of 1 year. Methods and analysis BALCoS is a prospective, single-site cohort study. Inclusion criteria include either a probable or confirmed history of SARS-CoV-2 infection with persistent symptoms consistent with the WHO definition of PCC, sufficient German language skills and age ≥18 years. At baseline, we collected detailed information on previous SARS-CoV-2 infections, symptom history, reinfections, COVID-19 vaccination status and pre-existing medical conditions. The study includes standardised psychometric assessments, physical performance tests, ecological momentary assessments (EMAs), neurocognitive testing and blood sample collection. Assessments are scheduled at baseline and at 3-month, 6-month and 12-month follow-up. All participants complete psychometric assessments at each time point. Blood samples are only collected at baseline. Neurocognitive testing and physical performance measures are collected at baseline and 12-month follow-up for in-person participants only. Participants who are unable to attend in person complete a remote version of the study, excluding these in-clinic assessments. EMAs are initiated the day after each time point and consist of eight questions over 10 consecutive days. The study is exploratory in nature, with a target sample size of 120 participants. BALCoS is part of the Horizon Europe Long COVID project, a multinational interdisciplinary research consortium integrating mechanistic, clinical and interventional studies. Ethics and dissemination The study was approved by the Ethics Commission of Northwest and Central Switzerland (BASEC-ID: 2023–00359) and is registered at ClinicalTrials.gov (ID: NCT05781893). All participants provide written informed consent. Study findings will be disseminated through peer-reviewed publications. Trial registeration number NCT05781893.
Development of the international prolonged grief disorder scale for the ICD-11: Measurement of core symptoms and culture items adapted for chinese and german-speaking samples Clare Killikelly, Ningning Zhou, Mariia Merzhvynska, Eva-Maria Stelzer, Tenzin Dotschung, Stefan Rohner, Lea Han Sun, Andreas Maercker Journal of Affective Disorders, 2020 BACKGROUND: Prolonged grief disorder (PGD) is a new mental health disorder included in the WHO ICD-11 however, the operationalization of the guidelines still needs to be empirically validated, particularly in different cultural contexts. Here we provide a preliminary validation study of the new International Prolonged Grief Disorder Scale (IPGDS) that serves to be the first self-report questionnaire directly based on the ICD-11 PGD and contains culturally adapted items. METHODS: In addition to core symptom items new culturally specific items were developed in two phases. Phase 1: key informant interviews with 10 German-speaking and 14 Chinese experts in grief and mental health, followed by a focus group with four bereaved German-speaking participants. Phase 2: 214 German-speaking and 325 Chinese bereaved participants completed self-report questionnaires. RESULTS: Phase 1 resulted in 19 potential culturally relevant items (e.g. feeling stuck in grief). Phase 2 exploratory factor analysis confirmed the one-dimensional nature of the IPGDS, additionally the 32-item scale revealed two factors (core grief and culturally specific symptoms). Psychometric analysis revealed strong internal consistency, concurrent validity and criterion validity. LIMITATIONS: The German-speaking and Chinese samples significantly differed in terms of several demographic variables including age, gender and type of loss. CONCLUSIONS: This preliminary validity study confirms that the IPGDS is a valid and reliable measure of the new ICD-11 PGD guidelines. This is the first scale of disordered grief to contain both core items and culturally specific supplementary items and aims to improve the clinical utility of the ICD-11 narrative approach.
Clinical Utility and Global Applicability of Prolonged Grief Disorder in the ICD-11 from the Perspective of Chinese and German-Speaking Health Care Professionals Eva-Maria Stelzer, Ningning Zhou, Mariia Merzhvynska, Stefan Rohner, Han Sun, Birgit Wagner, Andreas Maercker, Clare Killikelly Psychopathology, 2020 <b><i>Background:</i></b> Prolonged grief disorder (PGD) is included in the ICD-11 (11th edition of the International Classification of Diseases). The new PGD criteria reflect the requirements and recommendations of the World Health Organization for improved clinical utility and international applicability. Even though the ICD classification system is globally used, no research has investigated how healthcare professionals (HP) in non-Western countries may adopt this change for their own practice. <b><i>Objective:</i></b> The present study explored the extent to which the new PGD criteria were accepted and perceived to meet the standards for clinical utility and international applicability among Chinese and German-speaking HP. <b><i>Methods:</i></b> Individual semistructured interviews were conducted in person, by phone, or online (e.g., via Skype), with 24 Chinese (<i>n</i> = 10) and German-speaking (<i>n</i> = 14) HP working with bereaved populations in China and Switzerland, and analyzed using a qualitative framework analysis. Questions included “what items are currently missing from the PGD criteria?”. <b><i>Results:</i></b> Across all HP, the majority supported the inclusion of PGD and were generally aligned with the current criteria. HP found that the criteria distinguished between normal and abnormal grief and considered the criteria easy to use if their modifications were considered. Merits included, among others, improved clinical decision making, research promotion, and social acknowledgment. Main concerns included misdiagnosis, pathologization, and a lack of specificity of criteria. The importance of international applicability was emphasized across Chinese and German-speaking HP. Different grief-specific symptoms were identified by German-speaking and Chinese HP. <b><i>Conclusions:</i></b> These findings provide evidence for the clinical utility and international applicability of ICD-11 PGD criteria among German-speaking and Chinese HP, as well as cultural similarities and differences in the barriers to implementation of these criteria.
