Development and pilot testing of a patient-reported outcome measure to assess symptoms of parastomal hernia

The aim was to develop and pilot a patient-reported outcome measure (PROM) to assess symptoms of parastomal hernia (PSH).

Standard questionnaire development was undertaken (phases 1-3). An initial list of questionnaire domains was identified from validated colorectal cancer PROMs and from semi-structured interviews with patients with a PSH and health professionals (phase 1). Domains were operationalized into items in a provisional questionnaire, and 'think-aloud' patient interviews explored face validity and acceptability (phase 2). The updated questionnaire was piloted in patients with a stoma who had undergone colorectal surgery and had a computed tomography scan available for review. Patient-reported symptoms were examined in relation to PSH (phase 3). Three sources determined PSH presence: (i) data about PSH presence recorded in hospital notes, (ii) independent expert review of the computed tomography scan and (iii) patient report of being informed of a PSH by a health professional.

For phase 1, 169 and 127 domains were identified from 70 PROMs and 29 interviews respectively. In phase 2, 14 domains specific to PSH were identified and operationalized into questionnaire items. Think-aloud interviews led to three minor modifications. In phase 3, 44 completed questionnaires were obtained. Missing data were few: 5/660 items. PSH symptom scores associated with PSH presence varied between different data sources. The scale with the most consistent differences between PSH presence and absence and all data sources was the stoma appearance scale.

A PROM to examine the symptoms of PSH has been developed from the literature and views of key informants. Although preliminary testing shows it to be understandable and acceptable it is uncertain if it is sensitive to PSH-specific symptoms and further psychometric testing is needed.