UCSF

Background

Guidelines for management of small adrenal incidentalomas are mutually inconsistent. No cost-effectiveness analysis has been performed to evaluate rigorously the relative merits of these strategies.

Methods

We constructed a decision-analytic model to evaluate surveillance strategies for <4cm, nonfunctional, benign-appearing adrenal incidentalomas. We evaluated 4 surveillance strategies: none, one-time, annual for 2 years, and annual for 5 years. Threshold and sensitivity analyses assessed robustness of the model. Costs were represented in 2016 US dollars and health outcomes in quality-adjusted life-years.

Results

No surveillance has an expected net cost of $262 and 26.22 quality-adjusted life-years. One-time surveillance costs $158 more and adds 0.2 quality-adjusted life-years for an incremental cost-effectiveness ratio of $778/quality-adjusted life-years. The strategies involving more surveillance were dominated by the no surveillance and one-time surveillance strategies less effective and more expensive. Above a 0.7% prevalence of adrenocortical carcinoma, one-time surveillance was the most effective strategy. The results were robust to all sensitivity analyses of disease prevalence, sensitivity, and specificity of diagnostic assays and imaging as well as health state utility.

Conclusion

For patients with a < 4cm, nonfunctional, benign-appearing mass, one-time follow-up evaluation involving a noncontrast computed tomography and biochemical evaluation is cost-effective. Strategies requiring more surveillance accrue more cost without incremental benefit.