Clinical and economic burdens experienced by patients with painful diabetic peripheral neuropathy: An observational study using a Japanese claims database

BACKGROUND: Diabetic peripheral neuropathy (DPN) may often be painful. Despite the high prevalence of painful DPN (pDPN) among patients with diabetes mellitus (DM), understanding of its clinical and economic burden is limited. This study aimed to describe the clinical and economic burdens faced by patients with pDPN in Japan, and compared them with those experienced by patients with DPN but without painful symptoms (non-pDPN). METHODS: This retrospective, observational study used data from a large-scale, hospital-based Japanese claims database collected from April 2008 to June 2015. Comorbidities, clinical departments visited, length of hospital stay, and medical costs for the period of ± 6 months from the diagnosis of pDPN or non-pDPN were described for each group. Glycemic control status was examined for each group for patients with glycated hemoglobin data. RESULTS: The data of 8,740 patients with pDPN (mean age 70.0 years, 53.4% male) and 12,592 patients with non-pDPN (mean age 67.7 years, 55.7% male) were analyzed. Patients with pDPN had more comorbidities than patients with non-pDPN; 48.7% and 30.9% of patients in the respective groups had 20 or more comorbidities. The median length of hospital stay was 5 days longer in patients with pDPN. The median total medical costs were higher in patients with pDPN (\517,762) than in patients with non-pDPN (\359,909). Patients with pDPN spent higher median costs for medications, but the costs for glycemic control drugs were similar in both groups. For 3,372 patients with glycated hemoglobin data, glycemic control was similar between the two groups. CONCLUSION: Patients with pDPN experienced greater clinical and economic burdens than patients with non-pDPN, suggesting that patients who develop pDPN may suffer not only from the complications of DM and pain, but also from other comorbid disorders.