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

Abstract

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. The 14-item Multidimensional Nil Hallux Valgus Scale was developed. The scale has a score range of 0-60, with higher score indicating increased HV symptoms, complaints, and functional disorder. Among the patients referred to our clinic with HV diagnosis based on anterior-posterior non-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 Orthopaedic Foot and Ankle Society Hallux Metatarsophalangeal Interphalangeal Joints Scale (AOFAS-MTF-IF), Manchester Scale, and Short Form 36 Health Survey (SF-36) were used to test the validity and reliability of the new scale. From factor analyses, it was observed that the items clustered in 5 factors, which explained 73.2% 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 of the scale was estimated as 83.3%, and the Cronbach's alpha for the subheadings of the scale varied between 33.9% and 74.2%. High correlation was observed regarding test-retest reliability of the scale. 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 care professionals.