Statistical validation of the shorter-moldwin food sensitivity questionnaire for patients with interstitial cystitis/bladder pain syndrome

Abstract

Purpose: American Urological Association guidelines suggest dietary changes as first line treatment for interstitial cystitis/bladder pain syndrome. We previously developed a validated survey instrument to determine which foods, beverages and supplements exacerbate the symptoms of this condition. In this study we developed a shortened questionnaire that would provide an easily self-administered food symptom history useful for clinical practice and future research.

Materials and methods: Using data from our previously validated food sensitivity questionnaire we remodeled the original lengthy survey to an abbreviated list including the 35 most problematic comestibles. The instrument was reviewed by a panel of experts for face and content validity, and tested for internal consistency, readability and clarity, and test-retest reliability.

Results: Of the 124 patients who completed a baseline questionnaire 52 (42%) returned the second instrument 1 week after completing the first instrument. Internal consistency was high (α=0.96). A total of 47 patients (90.4%) indicated that they were food sensitive. Questionnaire test-retest reliability assessed by the Spearman correlation coefficient ranged from moderate (ρ=0.48 for Equal®) to very strong (ρ=0.90 for beer). Discrepancies between the survey instruments in individual comestibles occurred only 1% of the time.

Conclusions: Our short form diet history questionnaire based on a previously validated long form is a reliable, newly validated instrument that will help identify comestibles associated with interstitial cystitis/bladder pain syndrome symptoms. Its brevity makes it simple to administer and useful for dietary management in this population.

Keywords: cystitis; diet; interstitial; nutrition; questionnaires; urinary bladder.