Painful Diabetic Peripheral Neuropathy Study of Chinese Outpatients (PDNSCOPE): A Multicentre Cross-Sectional Registry Study of Clinical Characteristics and Treatment in Mainland China

Introduction This aim of this study was to delineate current clinical scenarios of painful diabetic peripheral neuropathy (PDN) and associated anxiety and depression among patients in Mainland China, and to report current therapy and clinical practices. Methods A total of 1547 participants were enrolled in the study between 14 June 2018 and 11 November 2019. Recruitment was conducted using a multilevel sampling method. Participants' demographics, medical histories, glucose parameters, Douleur Neuropathique 4 Questionnaire (DN4) scores, visual analogue scale (VAS) pain scores, Patient Health Questionnaire 9 (PHQ-9) scores, Generalised Anxiety Disorder 7 (GAD-7) scores and therapies were recorded. Results The male-to-female ratio was 1.09:1 (807:740), and the mean age at onset was 61.28 +/- 11.23 years. The mean DN4 score (+/- standard deviation) was 4.91 +/- 1.88. The frequencies of DN4 sub-item phenotypes were: numbness, 81%; tingling, 68.71%; pins and needles, 62.90%; burning, 53.59%; hypoaesthesia to touch, 50.16%; electronic shocks, 43.31%; hypoaesthesia to pinprick, 37.94%; brushing, 37.82%; painful cold, 29.61%; and itching, 25.86%. Age, diabetic duration, depression history, PHQ-9 score and GAD-7 score were identified as risk factors for VAS pain score. Peripheral artery disease (PAD) was a protective factor for VAS pain score. For all participants currently diagnosed with PDN and for those previously diagnosed PDN, fasting blood glucose (FBG) was a risk factor for VAS; there was no association between FBG and VAS pain score for PDN diagnosed within 3 months prior to recruitment. Utilisation rate of opium therapies among enrolled participants was 0.71% , contradiction of first-line guideline recommendation for pain relief accounted for 9.43% (33/350) and contradiction of second-line guideline recommendation for opium dosage form was 0.57% (2/350). Conclusion Moderate to severe neuropathic pain in PDN was identified in 73.11% of participants. Age, diabetic duration, depression history, PHQ-9 score, GAD-7 score and FBG were risk factors for VAS pain scores. PAD was protective factor. The majority of pain relief therapies prescribed were in accordance with guidelines.