Translation, Cross-Cultural Adaptation, Validation and Reliability of the Northwestern Dysphagia Patient Check Sheet (NDPCS) in Iran

Introduction Speech and language therapists (SLTs) require proper tools to detect dysphagia in the early stages. One of these screening tools is the Northwestern Dysphagia Patient Check Sheet (NDPCS). However, this tool needs to be adapted, validated, and shown to be reliable for the Persian culture. The aim of the present study was to report the validity and reliability of the Persian NDPCS (P-NDPCS). Materials and Methods The NDPCS has 28 items and five sections. Beaton's guidelines were followed in terms of the translation process. To report the content validity index (CVI) and the content validity ratio (CVR), eight SLTs experienced in swallowing disorders examined the content and face validities of the P-NDPCS in terms of the quality of translation, fluency, understandability, and the cultural context. In total, 140 patients with neurogenic and mechanical dysphagia were evaluated using the P-NDPCS. Internal consistency reliability was investigated using the Kuder-Richardson formula 20. The interclass correlation coefficient (ICC) was used for test-retest reliability. Results The P-NDPCS preserved the 28 items and the five categories of the original version. However, semantic and food adjustments were applied due to cultural differences. The scoring system was changed from safe/unsafe to yes/no for four subsections and to normal/abnormal for the oromotor section. Food requirements were also changed. The CVR and CVI were both 75%. The P-NDPCS was shown to have good content validity. The internal reliability was 0.95, indicating excellent reliability. Conclusion The equivalence between the original version of the NDPCS and the P-NDPCS was preserved. Our findings indicate that the P-NDPCSis a valid and reliable screening tool for the diagnosis of dysphagia in the early phase.