Exploring the implementation of a long COVID rehabilitation intervention: a mixed-methods process evaluation

Long COVID is recognised as a global public health concern, creating demand for rehabilitation. Despite a growing evidence base on long COVID rehabilitation interventions, knowledge of the implementation of these interventions remains limited, constraining adaptation and transfer across health care settings. In a previous study, the programme theory of a Danish community-based long COVID rehabilitation intervention was refined. However, uncertainties regarding its implementation remain. This study therefore aimed to explore the delivery and implementation of The Long COVID Rehabilitation Intervention.

This convergent mixed-methods process evaluation focused on what was delivered (reach, fidelity, and dose) and how it was delivered (implementation processes and adaptations). Quantitative data comprised baseline patient questionnaires and routine rehabilitation patient records. Qualitative data comprised a focus group interview with health professionals and an individual interview with the rehabilitation centre manager. Quantitative data were analysed descriptively, and qualitative data were analysed using content analysis. Findings were integrated narratively.

In total, 336 patients were included of whom 325 patients were referred for rehabilitation and 321 initiated the programme. Most patients were female, had a long education and were employed or enrolled in education prior to their COVID-19 disease. Median rehabilitation length was 183 days (IQR 131-261), and the patients received a median of 13 sessions (IQR 8-22). Overall, key intervention activities were consistently delivered. Most rehabilitees received a combination of individual and group-based sessions, with the energy management group being the most common. Variation over time was observed in median rehabilitation length and number of sessions delivered, reflecting adaptations to the intervention over time. Adaptations and implementation were influenced by contextual conditions concerning flexible delivery within a clear structure, knowledge of long COVID, space for reflection and adaptation, and organisational recognition and legitimacy.

This paper reports the implementation and delivery of The Long COVID Rehabilitation Intervention and highlights key contextual conditions that shaped these processes. These findings may inform adaptation and transfer of similar rehabilitation interventions to other health care settings. Future development and adaptation of long COVID rehabilitation should explicitly consider equity in access to ensure rehabilitation services reach diverse patient groups.

ClinicalTrials.gov, NCT06544382. Registered retrospectively on 9 August 2024.