Cost-Effectiveness of Therapeutic Drug Monitoring in Diagnosing Primary Aldosteronism in Patients With Resistant Hypertension.

Primary aldosteronism (PA) is present in up to 20% of patients with treatment-resistant hypertension (TRH). Investigation for PA in patients with TRH is recommended by current guidelines after medication nonadherence is excluded. Studies using therapeutic drug monitoring (TDM) have shown that >50% of patients with TRH are nonadherent to their prescribed antihypertensive medications. However, the relationship between the prevalence of PA and medication adherence as confirmed by TDM has not been previously assessed. A retrospective analysis from a hypertension referral clinic showed that prevalence of PA in adherent patients with TRH by TDM was significantly higher than in nonadherent patients (28% vs 8%, P<.05). Furthermore, cost analysis showed that TDM-guided PA screening was $590.69 less expensive per patient, with minimal impact on the diagnostic accuracy. These data support a TDM-guided PA screening approach as a cost-saving strategy compared with routine PA screening for TRH.