The Hausa Northwick Park Neck Pain Questionnaire: translation, cross-cultural adaptation and psychometric assessment in patients with non-specific neck pain

PURPOSE To translate and cross-culturally adapt the Northwick Park Neck Pain Questionnaire (NPQ) into Hausa and assess its psychometric properties. MATERIALS AND METHODS The NPQ was translated and cross-culturally adapted into Hausa using recommended guidelines. A consecutive sample of 92 Hausa-speaking patients with non-specific neck pain recruited from three tertiary hospitals in north-western Nigeria, completed the questionnaire to assess factorial validity (using confirmatory factor analysis), convergent validity (by correlating the Hausa-NPQ with the Numerical Pain Rating Scale [NPRS]), and internal consistency (using Cronbach's α). A subsample of 50 patients completed the questionnaire again 3 days after the first administration to assess relative reliability using intraclass correlation coefficients (ICC) and absolute reliability using standard error of measurement (SEM), smallest detectable change (SDC), and 95% limits of agreement (LOA). RESULTS The factor analysis confirmed a single-factor structure with excellent internal consistency (α = 0.94). The questionnaire showed a strong positive correlation with the NPRS (rho = 0.68). The ICC was 0.86, with SEM and SDC of 6.32 and 17.5, respectively. The LOA was - 29.3 to + 37.1 with no evidence of proportional bias. CONCLUSIONS The Hausa-NPQ is a valid and reliable measure of disability due to neck pain.