Table 1 The 10-step process used to translate the PEIRS-22 into Danish

(1) Preparation

We obtained the necessary permissions and established a clinical expert group

Permission was granted by the developer of PEIRS-22, Dr. Hamilton

Specialists in various cancer diagnoses (n = 11); professors (n = 2), senior researchers (n = 5), and doctoral students (n = 4) composed the clinical expert group

(2) Forward translation +( 3) Reconciliation

Key-in-country person and the project manager engaged a professional translator who initially translated PEIRS-22 from English to Danish

The three forward translations were reviewed and compared within the clinical expert group to identify discrepancies, and thus consensus translations were developed in the final reconciled forward translation. In a Danish context, the original English title proved to be too lengthy and general and was adjusted

(4) Back translation

Two additional translators being native speakers of English and fluent in the target language (Danish) translated the Danish version of PEIRS-22 into English

The two back-translated versions, as well as the translator's version, were intended to be conceptual rather than literal translations

(5) Back translation review

The original questionnaire and the two back translations were compared

Some phrases or words in English were found difficult to translate into Danish, for instance, “Convenience”, “Procedural requirements” and “Team Environment and Interaction” because no Danish words correspond to the original meaning. The wording in Danish was discussed until a consensus agreement was reached

(6) Harmonization

The clinical expert group compared the back-translated version against the original PEIRS-22 to examine discrepancies

The developer Dr. Hamilton was involved in clarifying wordings and meanings, for example, the alteration between “Research team members” and “The research project team”, after that we decided to use “research team members” consistently in the Danish version. Following discussions, the clinical expert group agreed on the revised Danish version to be ready for cognitive debriefing interviews

(7) Cognitive debriefing

An interview guide directed the semi-structured cognitive interviews

Interviews were recorded and transcribed verbatim

A total of seven patients agreed to participate after two declined due to lack of time. The patient's characteristics are shown in Table 2, column 1. MGC conducted the interviews and at the beginning of the interviews, the think-aloud [21] procedure was introduced to the patients. The patients were encouraged to express their thoughts and considerations when responding to the items

Overall, the patient partners valued the introduction to the questionnaire and found it easy to respond to. The patient partners highlighted that the items were understandable, however, they did not agree with the Danish words of convenience and the formulation of some of the items. The partners suggested adding a free text box. However, in the original questionnaire, this is not included and therefore it will not be a part of PEIRS-22. The patient partners expressed a suggestion to include a "not relevant" or "not applicable" option. However, after consulting with the clinical expert group and the scale's developer, Dr. Hamilton, we decided against it because it could interfere with the scale's ability to generate an interpretable total score

(8) Review of cognitive debriefing

The clinical expert group compared and discussed the comments and suggestions for improvement of the Danish version of PEIRS-22 to highlight and amend discrepancies

The clinical expert group discussed each item, considering the comments and perspectives shared by the patients. During this process, some of the suggestions were incorporated, while others remained unchanged due to their alignment with the original items. However, item FV3 asking: “I was offered sufficient recognition for my contributions (for example payment, authorship, or gifts)”, led to minor adjustments. The helping text was changed to: (for example catering, writing, lectures, or gifts). Any discrepancies were highlighted and discussed until the expert group reached a consensus

Dr. Hamilton clarified wordings and meanings, for example, the alteration between “Research team members” and “The research project team”. Hence, we decided to use “research team members” consistently in the Danish version

(9) Finalization + 10) Proofreading

The Danish PEIRS-22 was checked for typographical and grammatical errors

Finally, word positions and choices were adjusted based on the findings to fit the questionnaire into Danish, and MCG and KP proofread and finalized the PEIRS-22. The research team then approved the final linguistically validated and equivalent Danish version (Additional file: 3)