Development and validation of a condition-specific quality of life instrument for adults with esophageal atresia: the SQEA questionnaire

Abstract

The importance of multidisciplinary long-term follow-up for adults born with esophageal atresia (EA) is increasingly recognized. Hence, a valid, condition-specific instrument to measure health-related quality of life (HRQoL) becomes imperative. This study aimed to develop and validate such an instrument for adults with EA. The Specific Quality of life in Esophageal atresia Adults (SQEA) questionnaire was developed through focus group-based item generation, pilot testing, item reduction and a multicenter, nationwide field test to evaluate the feasibility, reliability (internal and retest) and validity (structural, construct, criterion and convergent), in compliance with the consensus-based standards for the selection of health measurement instruments guidelines. After pilot testing (n = 42), items were reduced from 144 to 36 questions. After field testing (n = 447), three items were discarded based on item-response theory results. The final SQEA questionnaire (33 items) forms a unidimensional scale generating an unweighted total score. Feasibility, internal reliability (Cronbach’s alpha 0.94) and test–retest agreement (intra-class coefficient 0.92) were good. Construct validity was discriminative for esophageal replacement (P < 0.001), dysphagia (P < 0.001) and airway obstruction (P = 0.029). Criterion validity showed a good correlation with dysphagia (area under the receiver operating characteristic 0.736). SQEA scores correlated well with other validated disease-specific HRQoL scales such as the GIQLI and SGRQ, but poorly with the more generic RAND-36. Overall, this first condition-specific instrument for EA adults showed satisfactory feasibility, reliability and validity. Additionally, it shows discriminative ability to detect disease burden. Therefore, the SQEA questionnaire is both a valid instrument to assess the HRQoL in EA adults and an interesting signaling tool, enabling clinicians to recognize more severely affected patients.