Direct and indirect costs of nephrolithiasis in an employed population: opportunity for disease management?

Abstract

Background: More than 5% of the United States population has been diagnosed with nephrolithiasis and about one half of (first-time) stone formers will have a recurrence within 5 years. The prevalence of nephrolithiasis is concentrated among working age adults, yet little prior work has examined the economic burden of the disease on employers and their employees. We sought to estimate the direct and indirect costs of nephrolithiasis for working age adults (18-64) with employer-provided insurance.

Methods: This was an observational study using retrospective claims data. Detailed medical and pharmacy claims from 25 large employers and absentee data from a subset of firms were used to estimate the direct and indirect costs associated with nephrolithiasis in a privately insured, non-elderly population. Multivariate regression models were used to predict health care expenditures for persons with and without the condition, controlling for differences in patient (health status) and plan characteristics.

Results: More than 1% of working-age adults were treated for nephrolithiasis in 2000. Prevalence was considerably higher among men and employees age 55 to 64. About one third of employees treated for nephrolithiasis in 2000 missed work due to the condition, with an average work loss for the entire treated population of 19 hours per person. Conditional on receiving treatment, the incremental costs of nephrolithiasis were 3,494 US dollars per person in 2000.

Conclusion: The direct and indirect costs of nephrolithiaisis are substantial among working-age adults. Interventions that prevent recurrence among known stone formers may be a cost-effective component of disease management programs.