HERO - HERnia outcome- a short form pain questionnaire developed for abdominal wall hernia patients-using psychometric methods.

PURPOSE: Outcomes after abdominal wall hernia surgery have traditionally been evaluated by the recurrence rate, which does not fully reflect the patient's perceived health. Patient-Reported Outcome Measures (PROMs) are therefore increasingly being used, but existing hernia-specific instruments are often long, multidimensional, or insufficiently validated for use in large cohorts like quality registries. The aim of this study was to develop and validate a short, reliable, register-adapted PROM, specifically addressing abdominal wall hernias, based on modern psychometric methods.

METHODS

A comprehensive item bank was constructed from existing PROMs, expert consensus and patient opinions to ensure content validity. After successive reduction, the questionnaire was tested in 165 patients (35 women mean age 50.4 years and 130 men mean age 58.2 years) having either an inguinal, umbilical or incisional hernia (74% inguinal, 18% umbilical and 8% incisional). The distribution for women was 31%, 45% and 24% respectively, and for men 84%, 11% and 5%. Data was analyzed using Rasch analysis to evaluate; dimensionality, response categories, precision, item fit, Differential Item Functioning (DIF), targeting and responsiveness. Logit-based measures were linearly transformed to a 0 - 100 scale for clinical interpretation.

RESULTS

The final instrument, HERO (HERnia Outcome), consists of six unidimensional questions with pain as the underlying construct (explained variance 66.3%). The scale shows good precision (person separation 2.58; reliability α = 0.87), well-ordered response categories and good item fit. One item demonstrated DIF related to incisional hernia and gender. Responsiveness after surgery was excellent (effect size 1.53).

CONCLUSION

HERO is a short, Rasch-validated hernia-specific PROM instrument that enables interval measurements of pain-related outcomes. Th instrument may be considered appropriate suited for use in large cohorts such as quality registries, and certain health-economic analyses.