Development and content validity testing of a colonoscopy-specific patient-reported experience measure: the Patient...

In endoscopic care, favourable patient experiences before, during and after a colonoscopy are essential for the patient's willingness to repeat the procedure. To ensure that significant experiences are measured, patients should be involved in creating the measurement instruments. Thus, the aim of the present study was to develop a colonoscopy-specific PREM by (1) operationalising patient experiences before, during and after a colonoscopy procedure and (2) evaluating its content validity.

The colonoscopy-specific PREM was developed in two stages: (1) operationalisation with item generation and (2) content validity testing. A previously developed conceptual model, based on a systematic literature review that illustrates patients' (n = 245) experiences of undergoing a colonoscopy, formed the theoretical basis. To assess the degree to which the PREM reflected patients' experiences before, during and after a colonoscopy procedure, content validity was tested-through face validity with healthcare professionals (n = 4) and cognitive interviews with patients (n = 14) having experienced a colonoscopy. Content validity index (CVI) was calculated to investigate the relevance of the items.

The Patient Experience Colonoscopy Scale (PECS) is a colonoscopy-specific PREM consisting of five different constructs: health motivation, discomfort, information, a caring relationship and understanding. Each construct was defined and generated into a pool of items (n = 77). After face-validity assessment with healthcare professionals, a draft 52-item version of the PECS was ready for content validity testing by the patients. During cognitive interviews the patients contributed valuable insights that led to rewording and removal of items. Results from the CVI suggest that the PECS and its content are relevant (I-CVI range 0.5-1, S-CVI/Ave = 0.86). The final PECS consists of 30 items representing a colonoscopy-specific PREM.

The PECS is a new 30-item PREM instrument designed for adult elective colonoscopy patients after they have undergone the procedure. Each item in the PECS derives from a conceptual model based on a systematic literature review. Patients and healthcare professionals were involved in developing the PECS, which measures colonoscopy-specific patient experiences before, during and after the procedure. The content validity testing positively contributed to the development of the PECS. Psychometric properties need to be evaluated further.