Using Real World Evidence to Describe Pulmonary Arterial Hypertension Treatment Patterns, Healthcare Resource Utilization, and Costs Associated with PDE-5 Inhibitor Monotherapy

Adherence and Discontinuation of Disease-Specific Therapies for Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

In patients with pulmonary arterial hypertension (PAH), the use of disease-specific therapies (i.e., endothelin receptor antagonists, phosphodiesterase type-5 inhibitors, soluble guanylate cyclase stimulators, prostacyclins, and prostanoids) has been associated with disease improvement and decreased mortality risk. We aimed to quantify the adherence and discontinuation rates for patients prescribed PAH-specific therapies.

METHODS

We performed a systematic review via searching MEDLINE, EMBASE, and the Cochrane Library from their inception to 4 March 2022 for observational studies published in English that reported data on adherence to and persistence with PAH-targeted therapies. Random-effects meta-analysis was performed to explore average adherence and discontinuation rates.

RESULTS

In all, 14 studies involving 14,861 individuals prescribed PAH-targeted therapies were included. The overall pooled proportion of patients adherent to their PAH-targeted medications was 60.9% (95% confidence interval [CI] 52.3-69.1%). The pooled proportions of patients adherent in questionnaire-based studies and in studies using prescription/dispensing data were 52.9% (95% CI 48.9-56.9%) and 62.9% (95% CI 53.1-72.2%), respectively. The pooled proportion of patients who discontinued their PAH-targeted medications was 42.3% (95% CI 31.6-53.3). Factors reported to impact adherence included administration frequency, length of time on treatment, co-payment, and occurrence of adverse events.

CONCLUSIONS

In the real world, a considerable proportion of patients prescribed PAH-specific therapies were non-adherent or discontinued. As diverse factors may influence treatment adherence, multifaceted interventions are needed to address this trend in order to improve patient outcomes.

REGISTRATION

The systematic review protocol was registered in the PROSPERO database (CRD42022316638).

Medication adherence, hospitalization, and healthcare resource utilization and costs in patients with pulmonary arterial hypertension treated with endothelin receptor antagonists or phosphodiesterase type-5 inhibitors

Adherence to therapy for pulmonary arterial hypertension is essential to optimize patient outcomes, but data on real-world adherence to different pulmonary arterial hypertension drug classes are limited. This retrospective database analysis evaluated relationships between adherence, hospitalization, and healthcare costs in pulmonary arterial hypertension patients treated with endothelin receptor antagonists or phosphodiesterase type-5 inhibitors. From the IQVIA Adjudicated Health Plan Database, patients with pulmonary arterial hypertension were identified based on diagnostic codes and prescriptions for endothelin receptor antagonists (ambrisentan, bosentan, macitentan) or phosphodiesterase type-5 inhibitors (sildenafil, tadalafil) approved for pulmonary arterial hypertension. Patients were assigned to the class of their most recently initiated (index) pulmonary arterial hypertension therapy between 1 January 2009 and 30 June 2015. Medication adherence was measured by proportion of days covered; patients with proportion of days covered ≥80% were considered adherent. The proportion of adherent patients was higher for endothelin receptor antagonists (571/755; 75.6%) than for phosphodiesterase type-5 inhibitors (970/1578; 61.5%; P < 0.0001). In both groups, hospitalizations declined as proportion of days covered increased. Among adherent patients, those on endothelin receptor antagonists had a significantly lower hospitalization rate than those on phosphodiesterase type-5 inhibitors (23.1% versus 28.5%, P = 0. 0218), fewer hospitalizations (mean (standard deviation) 0.4 (0.8) versus 0.5 (0.9); P = 0.02), and mean hospitalization costs during the six-month post-index ($9510 versus $15,726, P = 0.0318). Increasing adherence reduced hospitalization risk more for endothelin receptor antagonists than for phosphodiesterase type-5 inhibitors (hazard ratio 0.176 versus 0.549, P = 0.001). Rates and numbers of rehospitalizations within 30 days post-discharge were similar between groups. Mean total costs were higher with endothelin receptor antagonists than phosphodiesterase type-5 inhibitors in all patients ($91,328 versus $72,401, P = 0.0003) and in adherent patients ($88,867 versus $56,300, P < 0.0001), driven by higher drug costs.