Authors:
Cerebral palsy (CP) is the most common childhood physical disability, affecting 1.6/1000 live births globally. Up to 76% of people with CP experience pain, yet it is often poorly assessed and ineffectively managed. Best-practice chronic pain interventions are underutilised in CP, partly due to few valid and accessible tools for those with diverse cognitive and communication abilities. This thesis identified, adapted and validated tools for assessing pain interference with function, including emotional functioning, in all children and young people with CP, regardless of ability. A systematic review (Study 1) identified tools for assessing chronic pain interference in children and adults unable to self-report. The Paediatric Pain Profile was recommended for children and adolescents due to its strong psychometric properties. Importantly, the review found many young people with diverse needs can self-report but have lacked accessible tools. To address this, young people with CP, parents and clinicians participated in a mixed methods study (Study 2) and a Delphi study (Study 3). An online survey (, = 61) identified chronic pain tools with strong potential for modification. The modified Brief Pain Inventory (mBPI) and Fear of Pain Questionnaire for Children-Short Form (FOPQ-C-SF) rated highest. A qualitative study ( +10 more
= 61) identified chronic pain tools with strong potential for modification. The modified Brief Pain Inventory (mBPI) and Fear of Pain Questionnaire for Children-Short Form (FOPQ-C-SF) rated highest. A qualitative study (, = 44) reached consensus on key changes. Seven modifications were made to the FOPQ-C-SF and 21 to the mBPI, including visual, wording and scoring changes. Talking Mats, a visual communication tool, was recommended to improve accessibility. Two administration methods were developed: standard pen/paper and Talking Mats. The comprehensibility and feasibility of the adapted tools were confirmed in 22 children and young people with CP through cognitive interviews (Study 4), including those with cognitive impairment or communication needs. Studies 2 to 4 provided evidence of content validity, the most important psychometric property according to the COnsensus-based Standards for Measurement INstruments (COSMIN). The tools were renamed the Fear of Pain Questionnaire for Cerebral Palsy (FOPQ-CP) and Pain Interference Questionnaire for Cerebral Palsy (PIQ-CP). Study 5 examined structural validity of the FOPQ-CP and PIQ-CP in a cross-sectional study (, = 128). Results supported their validity (CFI > 0.96 or SRMR < 0.09). Self-report was possible for 79% of participants, including up to 37% who would have otherwise required proxy-report. The FOPQ-CP and PIQ-CP are valid and accessible tools for young people with CP. They can be used in clinical practice to identify those who may benefit from multidisciplinary pain interventions. They also offer a model for adapting tools for diverse populations.