Background: Orofacial pain, headaches, and neck pain are very common pain conditions in
the general population and might be associated in their pathophysiology, although this is not
yet clarified. The development and validation of a prediction inventory is important to minimize
risks. Most recent questionnaires have not focused on pain, but pain is the common symptom
in temporomandibular disorders, headaches, and neck pain. It is necessary to provide tools for
these conditions.
Objectives: The purpose of this study is to present the development and analysis of the
factorial structure and psychometric properties of a new self-administered questionnaire
(Craniofacial Pain and Disability Inventory [CF-PDI]) designed to measure pain, disability, and
functional status of the mandibular and craniofacial regions.
Study Design: Multicenter, prospective, cross-sectional, descriptive survey design. A
secondary 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 pain
patients. A sub-sample of 106 patients was asked to answer the questionnaire a second
time, to assess the test-retest reliability. The development and validation of the CF-PDI were
conducted using the standard methodology, which included item development, cognitive
debriefing, and psychometric validation. The questionnaire was assessed for the following
psychometric properties: internal consistency (Cronbach’s α); floor and ceiling effects; testretest reliability (Intraclass Correlation Coefficient [ICC]; Bland and Altman method); construct
validity (exploratory factor analysis); responsiveness (standard error of measurement [SEM] and
minimal detectable change [MDC]); and convergent validity (Pearson correlation coefficient),
by comparing visual analog scale (VAS), the Tampa Scale for Kinesiophobia (TSK-11), the Pain
Catastrophizing 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 associations
with theoretically similar constructs.
Results: The final version of the CF-PDI consists of 21 items. Exploratory factor analysis revealed
2 factors (“pain and disability” and “jaw functional status”), both with an eigenvalue greater
than one, explaining 44.77% of the variance. Floor or ceiling effects were not observed. High
internal consistency of the CF-PDI (Cronbach’s α: 0.88) and also of the 2 subscales (Cronbach’s
α: 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 2.4
and 7 points, respectively. The total CF-PDI score showed a moderate correlation with most of
the 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. Future
research 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 in
research 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