Craniofacial Pain and Disability Inventory (CFPDI): Development and Psychometric Validation of a New Questionnaire

Background: Orofacial pain, headaches, and neck pain are very common pain conditions inthe general population and might be associated in their pathophysiology, although this is notyet clarified. The development and validation of a prediction inventory is important to minimizerisks. Most recent questionnaires have not focused on pain, but pain is the common symptomin temporomandibular disorders, headaches, and neck pain. It is necessary to provide tools forthese conditions.Objectives: The purpose of this study is to present the development and analysis of thefactorial structure and psychometric properties of a new self-administered questionnaire(Craniofacial Pain and Disability Inventory [CF-PDI]) designed to measure pain, disability, andfunctional status of the mandibular and craniofacial regions.Study Design: Multicenter, prospective, cross-sectional, descriptive survey design. Asecondary analysis of the reliability of the measures was a longitudinal, observational study.Setting: A convenience sample was recruited from a hospital and 2 specialty clinics in Madrid,Spain.Methods: The study sample consisted of 192 heterogeneous chronic craniofacial painpatients. A sub-sample of 106 patients was asked to answer the questionnaire a secondtime, to assess the test-retest reliability. The development and validation of the CF-PDI wereconducted using the standard methodology, which included item development, cognitivedebriefing, and psychometric validation. The questionnaire was assessed for the followingpsychometric properties: internal consistency (Cronbach’s α); floor and ceiling effects; testretest reliability (Intraclass Correlation Coefficient [ICC]; Bland and Altman method); constructvalidity (exploratory factor analysis); responsiveness (standard error of measurement [SEM] andminimal detectable change [MDC]); and convergent validity (Pearson correlation coefficient),by comparing visual analog scale (VAS), the Tampa Scale for Kinesiophobia (TSK-11), the PainCatastrophizing Scale (PCS), the Neck Disability Index (NDI), and the Headache Impact Test-6(HIT-6). Multiple linear regression analysis was used to estimate the strength of the associationswith theoretically similar constructs.Results: The final version of the CF-PDI consists of 21 items. Exploratory factor analysis revealed2 factors (“pain and disability” and “jaw functional status”), both with an eigenvalue greaterthan one, explaining 44.77% of the variance. Floor or ceiling effects were not observed. Highinternal consistency of the CF-PDI (Cronbach’s α: 0.88) and also of the 2 subscales (Cronbach’sα: 0.80 – 0.86) was confirmed. ICC was found to be 0.90 (95% confidence interval [CI] 0.86 –0.93), which was considered to be excellent test-retest reliability. The SEM and MDC were 2.4and 7 points, respectively. The total CF-PDI score showed a moderate correlation with most ofthe assessed questionnaires (r = 0.36 – 0.52) and a strong correlation with the NDI (r = 0.65; P< 0.001). The NDI, VAS, and TSK-11 were predictors of CF-PDI.Limitations: Only self-reported measures were considered for convergent validity. Futureresearch should use physical tests to explore the clinical signs relating to pain and disability. Conclusion: The CF-PDI showed good psychometric properties. Based on the findings of this study, the CF-PDI can be used inresearch and clinical practice for the assessment of patients with craniofacial pain.Key words: Craniofacial pain, temporomandibular disorders, headache, neck pain, disability, development, questionnaire,reliability, psychometric validation, minimal detectable change