Aim: To describe and compare nurses' perceptions of the quality of fundamental care and related factors before and after a clinical development project, and to describe patients' perceptions of the quality of fundamental care.

Design: A descriptive, comparative study design.

Methods: Data were collected online from nurses in 2015 and 2021 with a structured questionnaire exploring fundamental care through 12 areas at the beginning and the end of a clinical developmental project. Patient experiences were collected with a paper-based questionnaire in 2021. A STROBE checklist was used as the reporting guideline.

Results: The nurses assessed the overall quality of fundamental care as high at both data collection timepoints. However, the quality deteriorated in general and in specific areas, including skin condition and cleansing, elimination, nutrition and blood circulation, during the follow-up period according to the nurses' experiences. A correlation was found between the areas of the quality of fundamental care. The registered nurses and the nurse managers expressed that not all areas of fundamental care were part of their work. The patients' experiences were mostly good. A small number of patients expressed a need to deal with issues related to their wellness of mind during their care.

Conclusions: The quality of fundamental care was perceived as high by nurses and patients, but the quality deteriorated during the follow-up period. It may be that the Covid-19 pandemic and a general shortage of nurses in the hospital contributed to nurses having to decide how to prioritise their tasks between fundamental and specialised care. It is therefore recommended to further develop fundamental care in the hospital.

Relevance to clinical practice: Nursing roles and practices need to be reviewed and developed further to better support nurses in their work to provide high-quality fundamental care. A systematic evaluation of the quality of fundamental care is recommended.

Patient or public contribution: Patients responded to the research questionnaire.