Development and validation of a Greek language version of the Manchester Foot Pain and Disability Index

BACKGROUND: The Manchester Foot Pain and Disability Index (MFPDI) is a 19 item questionnaire used to assess the severity and impact of foot pain. The aim of this study was to develop a Greek-language version of the MFPDI and to assess the instrument's psychometric properties. METHODS: The MFPDI was translated into Greek by three bilingual content experts and two bilingual language experts, and then back-translated into English to assess for equivalence. The final Greek version was administered, along with a questionnaire consisting medical history and the Medical Outcomes Study Short Form 36 (SF-36), to 104 Greek-speaking, community-dwelling people (64 female, 40 male), aged between 64 and 90 years (mean 73.00, SD 5.26) with disabling foot pain. RESULTS: The Greek translation of the MFPDI was found to have high internal consistency (Cronbach's α= 0.89, and item-total correlation coefficients from 0.33 to 0.72). Principal components analysis revealed a four-factor structure representing the constructs of functional limitation, pain intensity, concern with appearance and activity restriction, which explained 60.8% of the variance, with 38.9% of the variance explained by the first construct (functional limitation). Six items demonstrated different factor loadings to the original English version. CONCLUSION: The Greek-language version of the MFPDI appears to be a valid tool in assessing foot pain in Greek-speaking older people. The total MFPDI scores are comparable between the Greek and English version, however due to differences in the factor loadings of some items, between-language comparisons of MFPDI should be undertaken with some caution.