Comparison of all-cause, stroke, and bleed-specific healthcare resource utilization among patients with non-valvular atrial fibrillation (NVAF) and newly treated with dabigatran or warfarin

Real-world persistence to direct oral anticoagulants in patients with atrial fibrillation: a systematic review and network meta-analysis

OBJECTIVE

To conduct a systematic review and network meta-analysis of real-world evidence comparing adherence, persistence, cost, and utilization between oral anticoagulant (OAC) in non-valvular atrial fibrillation (NVAF) patients.

METHODS

A systematic search of MEDLINE and Embase (inception-July 2019) was conducted for published observational cohort studies comparing outcomes between ≥2 OACs. A network meta-analysis was performed to estimate odds ratios for non-persistence using a random-effects model.

RESULTS

There were 80 studies evaluating the outcomes of interest. However, due to a paucity in adherence studies and heterogeneity in adherence, cost, and utilization definitions, persistence was the focus of this network meta-analysis. There were 36 studies evaluating non-persistence in 395,593 participants, 24 of which used 3 gap definitions (30-, 60-, and 90-days); 18 unique studies evaluating non-persistence at 12 months were included in the network meta-analysis. Using 30- and 90-day gaps, all NOACs, when compared with VKAs, had lower odds of non-persistence (30-day OR (95%CI): apixaban: 0.63 (0.58, 0.69); rivaroxaban: 0.69 (0.62, 0.76); dabigatran: 0.89 (0.82, 0.97); 90-day OR (95%CI): apixaban: 0.33 (0.22, 0.47); rivaroxaban: 0.47 (0.36, 0.61); dabigatran 0.61 (0.44, 0.85)). When using a 60-day gap, dabigatran had higher odds of non-persistence vs VKAs (OR: 1.35; 95%CI: 1.12, 1.61), but there were no significant differences for apixaban and rivaroxaban. Apixaban had the lowest probability of non-persistence across the 3-gap definitions (95.7% with 30-day gap, 76.9% with 60-day gap, 98.4% with 90-day gap).

CONCLUSIONS

The current findings, despite multiple limitations, can raise awareness and understanding of real-world persistence associated with OAC therapy in NVAF patients.

Methodological considerations for investigating oral anticoagulation persistence in atrial fibrillation

Aims 

Reports of long-term oral anticoagulant (OAC) therapy for atrial fibrillation (AF) reveal highly variable, and generally suboptimal estimates of medication persistence. The objective of this review is to summarize current literature and highlight important methodological considerations for interpreting persistence research and designing studies of persistence on OAC treatment.

Methods and results 

We summarize differences in study methodology, setting, timing, treatment, and other factors associated with reports of better or worse persistence. For example, prospective compared with retrospective study designs are associated with higher reported persistence. Similarly, patient factors such as permanent AF or high stroke risk, and treatment with non-vitamin K oral antagonists relative to vitamin K antagonists are associated with higher persistence. Persistence has also been reported to be higher in Europe compared with North America and higher when the treating physician is a general practitioner compared with a specialist. We propose a framework for assessing and designing persistence studies. This framework includes aspects of patient selection, reliability and validity of measures, persistence definitions, clinical utility of measurements, follow-up periods, and analytic approaches.

Conclusions 

Differences in study design, patient selection, treatments, and factors such as the countries/regions where studies are conducted or the type of treating physician may help explain the variability in OAC persistence estimates. A framework is proposed to assess persistence studies. This may have utility to compare and interpret published studies as well as for planning of future studies.

All-Cause, Stroke-, and Bleed-Specific Healthcare Costs: Comparison among Patients with Non-Valvular Atrial Fibrillation (NVAF) Newly Treated with Dabigatran or Warfarin

OBJECTIVE

Our objective was to compare all-cause and stroke- and bleed-specific healthcare costs among patients with non-valvular atrial fibrillation (NVAF) treated with dabigatran or warfarin.

METHODS

Administrative claims data from the MarketScan® Databases for 2009-2014 were used. Patients with NVAF newly treated with dabigatran were matched 1:1 to those treated with warfarin. All-cause and stroke- and bleed-specific costs per patient per month (PPPM) ($US, year 2015 values) up to a 12-month follow-up period were analyzed. Stroke- or bleed-specific costs were defined as hospitalizations with stroke or bleed as the primary discharge diagnosis and outpatient claims with stroke or bleed diagnosis in any position. Differences in costs between dabigatran and warfarin users were assessed using descriptive and multivariate analyses.

RESULTS

A total of 18,980 dabigatran-treated patients were matched to corresponding warfarin-treated patients. Adjusted all-cause total healthcare, inpatient, and outpatient costs were significantly lower for the dabigatran cohort ($US3053 vs. 3433; $US904 vs. 1194; $US1594 vs. 1894, respectively; all p < 0.001), but mean pharmacy costs were significantly higher ($US556 vs. 345, p < 0.001). Stroke-specific total healthcare and outpatient costs were significantly lower for the dabigatran than for the warfarin cohort ($US30.37 vs. 40.99 and $US7.36 vs. 12.20, respectively; p < 0.05 for both values). Similarly, bleed-specific total healthcare and inpatient costs were significantly lower for the dabigatran than for the warfarin cohort ($US50.00 vs. 73.49 and $US27.75 vs. 48.66, respectively; p < 0.01 for both values).

CONCLUSION

Patients receiving dabigatran had significantly lower total all-cause, inpatient, and outpatient costs but higher pharmacy costs than those receiving warfarin. In addition, stroke-specific total and outpatient costs and bleed-specific total and inpatient costs were significantly lower in dabigatran users compared with warfarin users.