AUSTIN, TEX. – Adding a long-acting beta2-agonist to long-acting muscarinic antagonist therapy in patients with low- or moderate-complexity chronic obstructive pulmonary disease appeared to increase costs without providing significant benefit, according to findings from a retrospective cohort study.
The mean all-cause drug-related cost was $5,808 among 274 patients who received LAMA/LABA combination therapy between Jan. 1, 2009, and March 31, 2012, according to the MarketScan database, compared with $7,902 among 1,370 patients receiving LAMA monotherapy, Mona Khalid of Epstein Health, New York, reported at the annual meeting of the American College of Chest Physicians.
After adjustment for observed differences in baseline characteristics, such as disease complexity and comorbidities as assessed by Charlson comorbidity index score, the combination and monotherapy patients had similar all-cause health care resource utilization, with comparable rates of inpatient visits, office visits, and emergency department visits.
“Where we did see some difference was in COPD-related office visits. The patients on combination therapy were twice as likely to have an office visit,” Ms. Khalid said, noting that this difference between groups was statistically significant, and resulted in a mean of $92 more in costs in the combination therapy group.
The overall drug-related costs after adjustment were $1,003 higher in the combination therapy group, she said.
As for treatment adherence, 17% of patients in the combination therapy group had 80% or more days covered with therapy, compared with 25% of those in the monotherapy group. The medication possession ratio was 41% in the combination group, compared with 46% in the monotherapy group (adjusted difference about 5%).
The combination therapy patients included all patients receiving LAMA/LABA therapy identified in the database – which includes commercially insured patients and Medicare patients with supplemental coverage through an employer – during the study period. All were older than 40 years, had medical and pharmacy claims data available for at least 1 year before and after the index date, and had at least one COPD-related claim – but no claims for asthma, nonspecified bronchitis, respiratory cancer, cystic fibrosis, or LABA or LAMA use within the past year. LAMA patients were randomly selected using those same criteria and matched in a 5:1 ratio.
Most of the patients had low-complexity or moderate-complexity disease, although a few patients had severe disease, Ms. Khalid noted.
Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines call for the use of LAMA monotherapy early in the course of COPD among patients with low to moderate disease complexity. Some patients, however, initiate combination therapy during that phase of disease. The findings support the GOLD monotherapy recommendation in these patients, Ms. Khalid said, although they are limited by factors associated with the retrospective study design and an inability to control well for disease severity because of the use of “claims history as proxy.”
The study was conducted prior to approval of the single-inhaler LABA/LAMA combination therapy, she cautioned, so the results can’t necessarily be extended to that therapy. In addition, because of the use of the MarketScan database, the study findings can’t necessarily be extended to the uninsured population or the Medicaid population, Ms. Khalid noted.
The study was funded by Forest Laboratories. Ms. Khalid’s employer, Epstein Health, received consulting fees from Forest to conduct the study.