We aimed to assess usage and explore factors influencing the suitability of British Medical Journal (BMJ) Rapid Recommendations—a set of international guidelines meeting standards of trustworthiness—for adaptation and implementation, further defined as implementability.

Qualitative descriptive study with a multimethod approach.

We used citation screening and a survey to identify groups that had used any of a sample of 14 BMJ Rapid Recommendations in adoption, adaptation, de novo guideline development or implementation.

12 participants from a range of country income levels were interviewed, using semistructured interviews.

Interviews were analysed using thematic analysis to identify themes related to implementability of the guidelines. We compared these findings with those from a critical appraisal conducted using three different appraisal tools.

BMJ Rapid Recommendations are used in high-income, middle-income and low-income countries. We identified 33 instances of use. Our thematic analysis of the interviews uncovered 14 challenges to implementability, categorised under perceived trustworthiness, comprehensibility and practical relevance. The critical appraisals gave the BMJ Rapid Recommendations high scores on validity, but low scores on implementability and measurability. The challenges found in the interviews were generally corroborated by the appraisals, but the comparison also exposed tensions such as the complex interaction between methodological rigour and perceived credibility, the balance between novelty and compatibility with current practice, and the difficulty of offering globally applicable yet locally practical guidance.

Implementability challenges may limit effective use of international guidelines globally. Recognising and reflecting on tensions between rigour, credibility and contextual feasibility may help improve their uptake and value. The next phase of this research will explore strategies to enhance guideline implementability during their development.