RESUMO
BACKGROUND: Limited health resources necessitate prioritization for access to elective cholecystectomy in New Zealand. We aimed to develop and validate a patient questionnaire for determining the effect of gallstone disease on quality of life (QOL) and evaluate its potential role in appraising prioritization and outcomes from surgery. METHODS: The Otago gallstones condition-specific questionnaire (CSQ) was designed based on review of published reports, structural equation modelling, input from experts and patient feedback. Fifty-four patients with symptomatic gallstone disease completed the CSQ including a single question asking about global condition impact, along with other QOL measures: the Gallstone Impact Checklist and the Short Form-36 Health Survey. Validity and reliability of the CSQ were assessed using standard psychometric criteria and patient acceptance was explored in a semistructured interview. Patients' priority status for surgery was determined by two participating surgeons and resulting scores were correlated with the QOL measures. RESULTS: Average CSQ completion time was 2.7 (range 1-5) min and patients found its content concise and comprehensive. Validity was supported through high correlations with the Gallstone Impact Checklist (r = 0.74), the global condition impact (r = 0.69) and related dimensions of the Short Form-36 Health Survey. CSQ questions showed satisfactory internal consistency (Cronbach's alpha = 0.94) and reproducibility (ICC = 0.93, where ICC is intraclass coefficient). Of all the QOL measures, the CSQ was the most clinically relevant, showing the strongest relationship with surgeon-rated priority (r = 0.62). CONCLUSION: Evidence is provided to support the validity of the CSQ for assessing the effect of gallstone disease on QOL. The CSQ could be particularly valuable in aiding priority decisions surgeons make and may be useful in tracking subsequent outcomes.