Prevalence of other diabetes-associated complications and comorbidities and its impact on health care charges among patients with diabetic neuropathy.

Introduction: Diabetic neuropathy (DN) is a common complication associated with diabetes. This study assesses the prevalence of other diabetes-related complications or comorbidities among DN patients and its marginal contribution to health care charges.
Methods: Using administrative claims database, we studied commercially insured patients below 65 years old with at least one claim of DN anytime from July 2004 through June 2005 (Year 1). Using propensity scoring, a 10:1 ratio of demographically matched controls with diabetes but no DN was constructed. Both DN patients and controls had 12 months of continuous enrollment in Year 1 and Year 2 (July 2005-June 2006). We compared the Year 1 prevalence of other diabetes-associated complications or comorbidities between DN patients and diabetic controls. Controlling for comorbidities, we used multivariate regressions to examine the incremental impact of DN or any other diabetes-related complication or comorbidity on Year 2 health care charges.
Results: A higher percentage of DN patients had at least one other diabetes-related complication or comorbidity than diabetic controls. Individuals with DN had a higher prevalence of each individual other diabetes-related complication or comorbidity. Controlling for comorbidities, the presence of any other diabetes-related complication or comorbidity was statistically associated with higher outpatient pharmacy and total charges for both DN patients and controls. Total and outpatient pharmacy charges were also significantly higher for DN patients than for controls, among those with or without any other diabetes-related complications or comorbidities.
Conclusions: DN can occur in the absence of other diabetes-related complications or comorbidities. The presence of DN and any other diabetes-related complications or comorbidities significantly increases health care charges.