Τόμος 34 (2020) – Τεύχος 1 –Άρθρο 4 – Review of Clinical Pharmacology and Pharmacokinetics – Διεθνής Έκδοση – Volume 34 (2020) – Issue 1 – Article 4 – Review of Clinical Pharmacology and Pharmacokinetics – International Edition

Chrisi Vlachou and Theofanis Katostaras

Faculty of Nursing, School of Health Sciences, National and Kapodestrian University of Athens, Greece

Introduction: Diabetic neuropathy (DNU) and nephropathy (DNP) are frequent diabetes mellitus (DM) complications, and incidence increases with diabetes duration: patients with DM for 20 years have 90% probability for DNU and 40% for DNP.

Aim: This study was conducted to measure how diabetic patients value risk reduction of DNU and DNP, and estimate the maximum amount of money and percentage of monthly income these patients would pay for reduction of DNU and DNP risk.

Methods: All patients gave written consent. 419 DM patients, aged ≥60 years were evaluated using «willingness to pay» (WTP) for cost-benefit analysis. After receiving background information, patients were asked how much money they would pay per month for a drug that would reduce their DNU risk by 30%, 60% or 90% and DNP risk by 20% or 40%. Patients also indicated the importance of risk reduction on a 10-degree scale (0 = not important, 10 = extremely important). Data collected included demographic information, diabetes duration and treatment, presence of DNU, DNP or symptoms, and whether patients knew someone with DNU or DNP.

Data normality was assessed with the Kolmogorov-Smirnov test. Differences between more groups (by education level, diabetes duration or monthly income) were evaluated with the Kruskal-Wallis test. The Mann-Whitney test was used to compare groups (men vs. women, knowing vs. not knowing someone with DM, having vs. not having DNU or DNP) and for post-hoc comparisons. Factors influencing “WTP” were identified with logistic regression, using “WTP” > a certain income percentage as binary dependent variable. P values <0.05 were considered significant.

Results: Patients having DNU were willing to pay more for risk reduction (p=0.002, p=0.002 and p=0.001 for reduction by 30, 60 and 90%, respectively). Patients having DM for >10 years were willing to pay more (DNP: p=0.000, p=0.000 for risk reduction by 20 and 40% respectively, DNU: p=0.031, p=0.028 and p=0.003 for risk reduction by 30, 60 or 90% respectively). Diabetics using insulin were willing to pay more for risk reduction to 0% (p=0.002 for DNP, p=0.003 for DNU). Diabetics knowing other diabetics were also willing to pay more (DNP: p=0.047 and p=0.004 for reduction by 20% and 40%, respectively; DNU: p=0.025 for 30% and 90% reduction and p=0.019 for 60% reduction). Higher education and income were associated with willingness to pay more for risk reduction.

Conclusions: DNU and DNP risk reduction is important to DM patients, especially those having DM for >10 years, suffering from DNU and DNP or knowing someone with DM. Education and monthly income significantly influence the perceived value of DNU and DNP risk reduction.

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