Assessment of musculoskeletal pain in school children:Development and validation of a locally applicable pain tool

摘要

Introduction Musculoskeletal pain is not a variable, which can be observed and measured directly. Therefore, assessment invariably relies up on self-report. This is even difficult when dealing with children. Objective assessment is essential in epidemiological research. A pain tool should be both context and language specific. It is essential to ensure that a pain tool measures only musculoskeletal pain, not something else. Many tools evaluating pain in children are available internationally. But it is harder to find context-specific validated musculoskeletal pain assessment tools. Objective To develop and validate a musculoskeletal pain assessment tool for school children to be used in ergonomic contexts. Method An expert panel (n=10) participated in the development process of the Adolescent Musculoskeletal Pain Assessment Tool (AMPAT). Musculoskeletal pain was defined. Based on three hypothesised constructs of the pain experience (Sensory, Affective and Evaluative), relevant subclasses of each construct were identified. Sinhala word descriptors of pain were pooled and categorized under each construct of pain experience. In each subclass, five most suitable words were chosen and re-arranged assigning an intensity level of 1-5 in a Likert scale. Specific body locations were identified. A visual analogue scale quantified the intensity of pain. A composite pain score was formulated. Face, content and consensual validities of the AMPAT were established based on the opinion of the expert panel as the gold standard. A validation study was conducted among two groups, study (with pain n=88) and control (no pain n=87), of school-going adolescents attending clinics at a larger hospital. Construct validity was appraised by comparing pain scores of the study group before and after intervention to reduce pain and comparing pain scores of the control group. Convergent validity was established by comparing pain scores of study group with AMPAT and Adolescent Paediatric Pain Tool. Discriminant validity was appraised comparing pain scores and scores of Child Medical Fear Scale of the study group. A reliability analysis was carried out to assess the relationships between individual items in the scale in evaluating musculoskeletal pain. Results Construct validity was supported by the significant reduction in composite scores of the study group before and after an intervention (p<0.001) and also in comparison with the control group (p<0.001). A positive linear correlation between composite scores of the AMPAT and APPT with a Pearson Correlation Co-efficient of 0.68 (p<0.001) was reported to establish convergent validity. No significant linear correlation was found between composite scores of AMPAT and CMFS to appraise discriminant validity. The reliability analysis showed a Cronbach's alpha of 0.773. Conclusions AMPAT showed high validity and reliability in assessing musculoskeletal pain among adolescents. A similar methodology could be applied in different contexts to develop valid musculoskeletal pain assessment tools.