Painful Diabetic Neuropathy Anxiety Rasch-Transformed Questionnaire (PART-Q30((c)))

The association between painful diabetic neuropathy (PDN) and anxiety has been acknowledged using various anxiety scales capturing various fear entities. It has never been examined whether these generally applied anxiety questionnaires could be pooled to construct one overall anxiety metric. After completion by a cohort of 151 patients with PDN, data obtained from seven generally applied fear scales were stacked (n = 88 items) and subjected to Rasch analyses (pre-PART-Q88) to create the PDN overall Anxiety Questionnaire (PART-Q30((c))). We subsequently examined the impact of the final constructed PART-Q30((c)) on disability and Quality of Life (QoL) using the Rasch-Transformed Pain Disability Index (RT-PDI) and the Norfolk Quality of Life Questionnaire, Diabetic Neuropathy version (RT-Norfolk). The pre-PART-Q88 data did not meet Rasch model's expectations. Through stepwise examination for model fit, disordered thresholds, local dependency and item bias, we succeeded in reducing the data and constructing a 30 items overall anxiety scale (PART-Q30((c))) that fulfilled all model's expectations, including unidimensionality. An acceptable internal reliability was found (person-separation-index: 0.90). PART-Q30((c)) explained 36% of disability and combined with RT-PDI 63% of QoL (assessed with RT-Norfolk).