Validity of self-assessment of hallux valgus using the Manchester scale

Abstract

BackgroundHallux valgus (HV) is a common condition involving the progressive subluxation of the first metatarsophalangeal joint due to lateral deviation of the hallux and medial deviation of the first metatarsal. The objective of this study was to evaluate the re-test reliability and validity of self-assessment of HV using a simple clinical screening tool involving four standardised photographs (the Manchester scale), in order to determine whether this tool could be used for postal surveys of the condition.MethodsHV was assessed with the Manchester scale in 138 people aged 65 to 93 years of age (102 women and 36 men) as part of a larger randomised controlled trial. At the six month follow-up assessment, HV was reassessed to determine re-test reliability, and participants were asked to self-assess their degree of HV independent of the examiners. Associations between (i) baseline and follow-up assessments of the examiners and (ii) participant and examiner assessments were performed using weighted kappa statistics. Analyses were then repeated after HV was dichotomised as present or absent using unweighted kappa, and sensitivity and specificity of self-assessment of HV was determined.ResultsRe-test reliability of the examiners was substantial to almost perfect (weighted kappa = 0.78 to 0.90), and there was a substantial level of agreement between observations of the participants and the examiners (weighted kappa = 0.71 to 0.80). Overall, there was a slight tendency for participants to rate their HV as less severe than the examiners. When the Manchester scale scores were dichotomised, agreement was substantial to almost perfect for both re-test comparisons (kappa = 0.80 to 0.89) and substantial for comparisons between participants and examiners (kappa = 0.64 to 0.76). The sensitivity and specificity of self-assessment of HV using the dichotomous scale were 85 and 88%, respectively.ConclusionsThe Manchester scale demonstrates high re-test reliability, and self-assessment scores obtained by participants are strongly associated with scores obtained by examiners. These findings indicate that the tool can be used with confidence in postal surveys to document the presence and severity of HV.Trial registrationACTRN12608000065392

Validity and Reliability of Hallux Valgus Angle Measured on Digital Photographs

“…The 4-level Manchester scale has been shown to have good retest reliability (weighted κ = 0.78-0.90) 15 and a strong association with radiographic HV angle measurements (Spearman ρ = 0.73, P<.01). 17 Similarly, a 5-grade scale described by Roddy et al 23 has been shown to have very good observer repeatability (weighted κ = 0.82).…”

Ultrasound evaluation of intrinsic plantar muscles and fascia in hallux valgus

“…An excellent interexaminer repeatability (kappa coefficient κ = 0.86) was showed for this 4-point scale. [24] A high inter-rater reliability and validity of the HV angle between the photographic measurements and radiographs was demonstrated. Their ICC (>0.96) and Pearson correlation coefficient ( r  = 0.96) were excellent, and also their confidence interval (95% CI) limits of agreement were acceptable.…”

Characteristics of foot structure and footwear associated with hallux valgus: a systematic review

“…Associated factors that were reported as categorical variables were collapsed into dichotomous categories for analysis. Subgroups of mild, moderate, and severe HV classified according to the Manchester Scale 33 were collapsed into the following dichotomous groupings: none/mild, or moderate/severe HV 34 . Additional data was requested from authors where means and SDs had not been provided in the original publication.…”