Propensity score methods (PSMs) such as matching and weighting have become a mainstay for the estimation of treatment effects from observational data. PSMs require the choice of a treatment effect of interest given a specific target population or subpopulation. The most commonly used treatment effects in observational studies are the average treatment effect (ATE) and the average treatment effect among the treated population (ATT). While the traditional matching approach usually discards observations that cannot be matched and is therefore mainly used for estimation of the ATT, the weighting approach utilizes all observations in most cases and can be used for estimation of both, the ATE and ATT. One concern when using the weighting approach is the occurrence of large weights which may disproportionately influence the results and yield estimates with high variance. Recently several newer approaches, including matching weights and overlap weights have been proposed to overcome these limitations. However, this may complicate the interpretation of the results as the population to be inferred depends on the PS estimate itself.

116 Background: As mCRC and its treatment can adversely impact quality of life (QoL), maintaining QoL is an important treatment goal in addition to improving survival outcomes, particularly as patients progress through lines of therapy. In the global, randomized, double-blind, phase 3 FRESCO-2 trial (NCT04322539), fruquintinib (F) + BSC vs placebo (P) + BSC demonstrated significantly improved overall survival (OS) (median 7.4 months vs 4.8 months; HR 0.66, 95% confidence interval [CI] 0.55–0.80) and progression-free survival, with a manageable safety profile and without deterioration of QoL in heavily pretreated patients with refractory mCRC. The objective of this post-hoc Q-TWiST analysis was to assess the quality-adjusted survival benefit of F + BSC in the context of the FRESCO-2 trial. Methods: The Q-TWiST analysis was applied to all 691 randomized patients from FRESCO-2 (F + BSC n=461 vs P + BSC n=230). Survival time of each patient was partitioned into 3 health states: time spent with treatment-emergent adverse events of CTCAE grade 3 or 4 before disease progression (TOX), time before disease progression without toxicity (TWiST), and time between disease progression and death or censoring (REL). Assuming utility coefficients of 1 for TWIST and 0.5 for TOX and REL, Q-TWiST was calculated as the utility-weighted sum of the time spent in each health state. The mean time spent in each of the 3 health states was calculated for each treatment group using Kaplan-Meier analysis, and a 95% CI for the difference between treatment was calculated using the nonparametric bootstrap method. Results: Q-TWiST was 6.25 months for F + BSC and 4.21 months for P + BSC, a difference of 2.04 (95% CI 1.51–2.57) months longer with F + BSC vs P + BSC. This difference in Q-TWiST was mainly driven by the difference in the TWiST component (2.14 months [95% CI 1.78–2.49]; F + BSC 4.06 months vs P + BSC 1.92 months). The relative Q-TWiST gain, calculated as the difference in Q-TWiST divided by the mean OS time of the P + BSC group, was 31.4% in favor of F + BSC. Conclusions: In the FRESCO-2 trial, F + BSC demonstrated a clinically meaningful quality-adjusted survival benefit compared with P + BSC in heavily pretreated patients with refractory mCRC. Clinical trial information: NCT04322539 .

OBJECTIVES:Emerging treatments for relapsed or refractory multiple myeloma (rrMM) have led to increasing options for many patients. This study aimed to assess changes in utilization of these options in Germany with a focus on modern triplet regimens including new agents, such as carfilzomib, ixazomib, elotuzumab and daratumumab, and to evaluate whether this had an impact on rrMM-related outcomes over time.METHODS:The study population consisted of 1255 rrMM patients who were assigned to one of the following 6 treatment groups: immunomodulatory drug (IMiD)-based doublets, proteasome inhibitor (PI)-based doublets, daratumumab monotherapy, PI-IMiD-based triplets, monoclonal antibodies (mAbs)-based triplets, or other treatment.RESULTS:Use of triplet-based therapy regimens increased from 5.9% in 2014 to 31.4% in 2017. In parallel, use of IMiD-based doublets decreased from 74.3% in 2014 to 37.6% in 2017. Over the same time period, the risk of death decreased by 32% and the risk of hospitalization which was reduced by 30%. The risk for serious adverse events remained unchanged.CONCLUSIONS:Between 2014 and 2017, the use of triplet-based therapy regimens for rrMM in Germany has significantly increased and this was associated with a significant decline in deaths and hospitalizations without an increased incidence of serious adverse events.

Background In Germany, several triplet therapies for treating relapsed or refractory multiple myeloma (rrMM) patients have recently been approved. While most of them are administered intravenously, ixazomib-based combination is the only orally bioavailable regimen. Objective To conduct a 1-year and 3-year budget impact analysis (BIA) of different novel triplets to treat patients with rrMM in second or subsequent therapy lines accounting for costs covered by German statutory health insurance (SHI). Methods A 3-state partitioned survival model (PSM) was developed to evaluate the budget impact of the following regimens: carfilzomib plus lenalidomide plus dexamethasone (KRd), elotuzumab plus lenalidomide plus dexamethasone (ERd), daratumumab plus lenalidomide plus dexamethasone (DRd), and ixazomib plus lenalidomide plus dexamethasone (IRd). The analysis included direct medical costs such as drug acquisition, comedication and preparation for parenteral solutions, drug administration and other 1-time costs, adverse event management costs and direct non-medical costs, such as transportation costs. Results Based on current drug market shares in German healthcare market, the estimated costs after 1 year of treatment was €551 million (KRd), €163 million (ERd), €584 million (DRd), and €95 million (IRd). The total budget impact of €1393 million is mainly driven by drug acquisition and subsequent therapy costs. Conclusion Among the regimens of interest, the oral-based therapy regimens offered cost advantages over intravenous-based therapy regimens. The higher overall costs of intravenous therapy regimens were attributed primarily to higher drug acquisition costs.

Background Underuse of oral anticoagulation (OAC) for stroke prevention in atrial fibrillation (AF) results in thousands of preventable strokes in Germany each year. This study aimed to assess changes in antithrombotic therapy in AF patients after increased use of direct oral anticoagulants (DOACs) in Germany and to evaluate whether the adoption of DOAC therapy was associated with changes in AF-related stroke and bleeding over time. Methods Analyses were carried out on a large claims-based dataset of 4 million health-insured Germans. The study population consisted of 601,261 prevalent AF patients between 2011 and 2016 who were assigned to one of the following four treatment groups: DOAC, VKA, antiplatelets or no antithrombotic treatment. Treatment patterns were descriptively analysed and represented by cohort and CHA(2)DS(2)-VASc score. Clinical outcomes before and after the adoption of DOAC therapy were assessed using Poisson regression models. Results Use of OAC increased from 42 to 61% between 2011 and 2016, mainly due to more frequent prescription of DOACs. However, some underuse of OAC therapy remained even in high risk AF patients. In parallel with the increased prescription rate of OAC, there was an overall 24% incidence reduction in stroke between 2011 and 2016 which was mainly driven by reductions in ischemic strokes. Over the same time period the risk for major bleeding remained unchanged. Conclusion Between 2011 and 2016, the use of guideline-conform antithrombotic therapy in Germany has significantly increased. This was associated with a significant decline in strokes without an increased incidence of bleeding complications.

Background This study assessed changes in anticoagulation therapy over time in patients with atrial fibrillation (AF). Methods Analyses were performed on a claims-based dataset of 4 million health-insured individuals. The study population consisted of patients newly initiating a non-vitamin-K oral anticoagulants (NOACs) or vitamin K antagonist (VKA) for AF between 2013 and 2016. The study outcomes consisted of the proportion of patients who had (1) discontinued OAC treatment, (2) switched from VKA to NOAC, (3) switched from NOAC to VKA or (4) switched from one NOAC to another. Predictors of discontinuation or switching of OAC treatment were determined by Cox proportional hazards regression models with time-independent and time-dependent covariates. Results The study population comprised 51,606 AF patients initiating VKA ( n =21,468, 41.6%), apixaban ( n =8,832, 17.1%), dabigatran ( n =3,973, 7.7%) or rivaroxaban ( n =17,333, 33.6%). After 1year, 29.9% of VKA and 29.5% of NOAC patients had discontinued OAC treatment without switching to another anticoagulant. A total of 10.7% of VKA patients switched to NOACs within 1year, whereas 4.9% NOAC patients had switched to VKA. Of AF patients who were initiated on a NOAC, 5.2% switched to another NOAC. Treatment changes among NOAC starters were strongly associated with occurrence of stroke, myocardial infarction and gastrointestinal bleeding after treatment initiation. For VKA starters switching to a NOAC, stroke and bleeding events were associated with an increased likelihood of switching. Conclusion Overall discontinuation rates of VKA and NOACs are comparable over the first year of therapy, while switching from VKA to NOAC was more common than from NOAC to VKA. The majority of treatment changes were associated with clinical events.

Background Venous thromboembolism (VTE) mainly manifests as deep vein thrombosis (TVT) or pulmonary embolism (LE), and is the third most common cardiovascular disease worldwide. However, robust evidence on the incidence of VTE in Germany is lacking. Objective Estimation and comparison of the incidence of VTE based on different routine data sources of the German healthcare system. Methods Estimates and comparisons of the incidence of VTE, TVT and LE were made using two databases that both covered the inpatient and the outpatient setting; the DaTraV database comprising information of all persons subject to compulsory health insurance, and the Health Risk Institute (HRI) database derived from approximately 70 statutory health insurance funds. In addition, IMS Disease Analyzer, a medical record database comprising information from the outpatient setting, was used as a data source. Results Patterns of age- and sex-specific VTE incidence estimates were comparable between all databases used. However, estimates based on the medical record database were comparatively high. Analyses of DaTraV data led to a VTE incidence of 0.14%. Use of HRI data yielded comparable results (0.17–0.20%). VTE incidence based on data of the IMS Disease Analyzer was comparatively high (0.32%). Discussion Results on the VTE incidence based on DaTraV or HRI date are comparable to international evidence, whereas the use of the IMS Disease Analyzer data presumably led to an overestimation due to double-counting of VTE cases. Different types of routine healthcare data sources can therefore lead to very heterogeneous results. Thus, the selection of adequate data sources strongly depends on the study question and the quality of the dataset.

All pivotal trials have evaluated non-vitamin K oral antagonists (NOACs) against warfarin. However, in some regions of the world, phenprocoumon is the most widely used vitamin K antagonist (VKA). There is little evidence documenting effectiveness and safety of NOACs compared with phenprocoumon in atrial fibrillation (AF). Aretrospective cohort study using a German claims database was conducted to assess effectiveness (stroke, systemic embolism [SE]) and safety (bleeding leading to hospitalization) during therapy with NOACs and phenprocoumon in 61,205 AF patients. Hazard ratios (HRs) for effectiveness and safety outcomes were derived from Cox proportional hazard models, adjusting for baseline characteristics. Propensity score matching was performed as a sensitivity analysis. As a prespecified subgroup analysis, the effects of reduced NOAC dosing were compared with phenprocoumon. A total of 61,205 patients were identified in whom phenprocoumon (n = 23,823, 38.9%), apixaban (n = 10,117, 16.5%), dabigatran (n = 5,122, 8.4%), or rivaroxaban (n = 22,143, 36.2%) was initiated. After adjusting for baseline confounders, all three NOACs tested had significantly lower risks of stroke/SE compared with phenprocoumon (apixaban-HR: 0.77, 95% CI: 0.66-0.90; dabigatran-HR: 0.74, 95% CI: 0.60-0.91; rivaroxaban-HR: 0.86, 95% CI: 0.76-0.97). Apixaban (HR: 0.58, 95% CI: 0.49-0.69) and dabigatran (HR: 0.64, 95% CI: 0.50-0.80) were associated with lower bleeding risks than phenprocoumon, whereas the risk was similar for rivaroxaban and phenprocoumon. All threeNOACs showed reduced riskof intracranial bleeding compared with phenprocoumon. Reduced doses of NOACs were predominantly used in patients with advanced age and comorbidities with generally similar effectiveness and safety benefits compared with phenprocumon as standard-dose NOACs.

Background: Venous thromboembolism (VTE) mainly manifests as deep vein thrombosis (TVT) or pulmonary embolism (LE), and is the third most common cardiovascular disease worldwide. However, robust evidence on the incidence of VTE in Germany is lacking. Objective: Estimation and comparison of the incidence of VTE based on different routine data sources of the German healthcare system. Methods: Estimates and comparisons of the incidence of VTE, TVT and LE were made using two databases that both covered the inpatient and the outpatient setting; the DaTraV database comprising information of all persons subject to compulsory health insurance, and the Health Risk Institute (HRI) database derived from approximately 70 statutory health insurance funds. In addition, IMS Disease Analyzer, a medical record database comprising information from the outpatient setting, was used as a data source. Results: Patterns of age-and sex-specific VTE incidence estimates were comparable between all databases used. However, estimates based on the medical record database were comparatively high. Analyses of DaTraV data led to a VTE incidence of 0.14%. Use of HRI data yielded comparable results (0.17-0.20%). VTE incidence based on data of the IMS Disease Analyzer was comparatively high (0.32%). Discussion: Results on the VTE incidence based on DaTraV or HRI date are comparable to international evidence, whereas the use of the IMS Disease Analyzer data presumably led to an overestimation due to double counting of VTE cases. Different types of routine healthcare data sources can therefore lead to very heterogeneous results. Thus, the selection of adequate data sources strongly depends on the study question and the quality of the dataset.

Non-vitamin K antagonist oral anticoagulants (NOACs) are at least as effective and safe as vitamin K antagonists (VKAs) for stroke prevention in atrial fibrillation (AF). All pivotal trials have compared NOACs to warfarin. However, other VKAs are commonly used, for instance phenprocoumon.