Development of Multidimensional Nil Hallux Valgus Scale: a reliability and validity study

Objective: The aim of this study was to develop a disease-specific multidimensional hallux valgus(HV) scale, as well as to establish the validity and reliability thereof.Methods: The 14-item Multidimensional Nil Hallux Valgus Scale was developed. The scale has ascore range of 0–60, with higher score indicating increased HV symptoms, complaints, and functionaldisorder. Among the patients referred to our clinic with HV diagnosis based on anterior-posteriornon-weight-bearing radiography of the affected foot, 129 feet of 66 patients (63 bilateral, 3 unilateral)were included in the study. In clinical evaluations of these HV patients, American OrthopaedicFoot and Ankle Society Hallux Metatarsophalangeal Interphalangeal Joints Scale (AOFAS-MTFIF),Manchester Scale, and Short Form 36 Health Survey (SF-36) were used to test the validity andreliability of the new scale.Results: From factor analyses, it was observed that the items clustered in 5 factors, which explained73.2% of the variance. Floor and ceiling effects were observed to be within normal limits (floor effect:3.1%; ceiling effect: 0.8%). The Cronbach’s alpha level related with the overall internal consistency ofthe scale was estimated as 83.3%, and the Cronbach’s alpha for the subheadings of the scale variedbetween 33.9% and 74.2%. High correlation was observed regarding test-retest reliability of the scale.Conclusion: This newly developed scale allows for the holistic evaluation of HV including the condition-specific parameters and is a valid and reliable scale that can be conveniently used by health careprofessionals.