How microsimulation translates outcome estimates to patient lifetime event occurrence in the setting of heart valve disease.

Treatment decisions in healthcare often carry lifelong consequences that can be challenging to foresee. As such, tools that visualize and estimate outcome after different lifetime treatment strategies are lacking and urgently needed to support clinical decision-making in the setting of rapidly evolving healthcare systems, with increasingly numerous potential treatments. In this regard, microsimulation models may prove to be valuable additions to current risk-prediction models. Notable advantages of microsimulation encompass input from multiple data sources, the ability to move beyond time-to-first-event analysis, accounting for multiple types of events and generating projections of lifelong outcomes. This review aims to clarify the concept of microsimulation, also known as individualized state-transition models, and help clinicians better understand its potential in clinical decision-making. A practical example of a patient with heart valve disease is used to illustrate key components of microsimulation models, such as health states, transition probabilities, input parameters (e.g. evidence-based risks of events) and various aspects of mortality. Finally, this review focuses on future efforts needed in microsimulation to allow for increasing patient-tailoring of the models by extending the general structure with patient-specific prediction models and translating them to meaningful, user-friendly tools that may be used by both clinician and patient to support clinical decision-making.

Benefits of sphingosine-1-phosphate receptor modulators in relapsing MS estimated with a treatment sequence model.

BACKGROUND: Three sphingosine-1-phosphate receptor (S1PR) modulators are currently available as disease-modifying therapies (DMTs) for relapsing MS in the Netherlands (i.e. fingolimod, ozanimod and ponesimod). We aimed to identify which S1PR modulator yields the highest benefit from a health-economic and societal perspective during a patient's lifespan. METHODS: Incorporating Dutch DMT list prices, we used the ErasmusMC/iMTA MS model to compare DMT sequences, including S1PR modulators and eight other DMT classes, for treatment-naïve patients with relapsing MS in terms of health outcomes (number of lifetime relapses, time to Expanded Disability Status Scale (EDSS) 6, lifetime quality-adjusted life years (QALYs)) and cost-effectiveness (net health benefit (NHB)). We estimated the influence of list price and EDSS progression on cost-effectiveness outcomes. RESULTS: In deterministic and probabilistic analysis, DMT sequences with ponesimod have lower lifetime costs and higher QALYs resulting in a higher average NHB compared to sequences with other S1PR modulators. Ponesimod remains the most cost-effective S1PR modulator when EDSS progression is class-averaged. Given the variable effects on disability progression, list price reductions could make fingolimod but not ozanimod more cost-effective than ponesimod. CONCLUSION: Our model favours ponesimod among the S1PR modulators for the treatment of relapsing MS. This implies that prioritizing ponesimod over other S1PR modulators translates into a more efficacious spending of national healthcare budget without reducing benefit for people with MS. Prioritizing cost-effective choices when counselling patients contributes to affordable and accessible MS care.

Effectiveness and Cost-Effectiveness of 360 Disease-Modifying Treatment Escalation Sequences in Multiple Sclerosis.

OBJECTIVES: The rapid expansion in treatment options for relapsing-remitting multiple sclerosis (RRMS) of the past decade requires clinical decision making on the sequential prescription of these treatments. Here, we compare 360 treatment escalation sequences for patients with RRMS in terms of health outcomes and societal costs in The Netherlands. METHODS: We use a microsimulation model with a societal perspective, developed in collaboration with MS neurologists, to estimate the effectiveness and cost-effectiveness of 360 treatment sequences starting with first-line therapies in RRMS. This model integrated data on disease progression, disease-modifying treatment efficacy, clinical decision rules, age-dependent relapse rates, quality of life, healthcare, and societal costs. RESULTS: Costs and health outcomes were overlapping among different treatment escalation sequences. In our model for RRMS treatment, optimal lifetime health outcomes (20.24 ± 1.43 quality-adjusted life-years [QALYs], 6.11 ± 0.30 relapses) were achieved with the sequence peginterferon-dimethyl fumarate-ocrelizumab-natalizumab-alemtuzumab. The most cost-effective sequence (peginterferon-glatiramer acetate-ocrelizumab-cladribine-alemtuzumab) yielded numerically worse health outcomes per patient (19.59 ± 1.43 QALYs, 6.64 ± 0.43 relapses), but resulted in €98 127 ± €19 134 less costs than the most effective treatment sequence. CONCLUSIONS: Effectiveness estimates of treatments have overlapping confidence intervals but the treatment sequence that yields most QALYs is not the most cost-effective option, also when taking uncertainty into account. It is important that neurologists are aware of cost constraints and its relationship with prescription behavior, but treatment decisions should be individually tailored.

Being Transparent About Brilliant Failures: An Attempt to Use Real-World Data in a Disease Model for Patients with Castration-Resistant Prostate Cancer.

BACKGROUND: Real-world disease models spanning multiple treatment lines can provide insight into the (cost) effectiveness of treatment sequences in clinical practice. OBJECTIVE: Our objective was to explore whether a disease model based solely on real-world data (RWD) could be used to estimate the effectiveness of treatments for patients with castration-resistant prostate cancer (CRPC) that could then be suitably used in a cost-effectiveness analysis. METHODS: We developed a patient-level simulation model using patient-level data from the Dutch CAPRI registry as input parameters. Time to event (TTE) and overall survival (OS) were estimated with multivariate regression models, and type of event (i.e., next treatment or death) was estimated with multivariate logistic regression models. To test internal validity, TTE and OS from the simulation model were compared with the observed outcomes in the registry. RESULTS: Although patient characteristics and survival outcomes of the simulated data were comparable to those in the observed data (median OS 20.6 vs. 19.8 months, respectively), the disease model was less accurate in estimating differences between treatments (median OS simulated vs. observed population: 18.6 vs. 17.9 [abiraterone acetate plus prednisone], 24.0 vs. 25.0 [enzalutamide], 20.2 vs. 18.7 [docetaxel], and 20.0 vs. 23.8 months [radium-223]). CONCLUSIONS: Overall, the disease model accurately approximated the observed data in the total CRPC population. However, the disease model was unable to predict differences in survival between treatments due to unobserved differences. Therefore, the model is not suitable for cost-effectiveness analysis of CRPC treatment. Using a combination of RWD and data from randomised controlled trials to estimate treatment effectiveness may improve the model.

Methodological Challenges in the Economic Evaluation of a Gene Therapy for RPE65-Mediated Inherited Retinal Disease: The Value of Vision.

The emergence of gene therapies challenge health economists to evaluate interventions that are often provided to a small patient population with a specific gene mutation in a single dose with high upfront costs and uncertain long-term benefits. The objective of this study was to illustrate the methodological challenges of evaluating gene therapies and their implications by discussing four economic evaluations of voretigene neparvovec (VN) for the treatment of RPE65-mediated inherited retinal disease. The checklist for economic evaluations of gene therapies of Drummond et al. was applied to the economic evaluations of VN performed by US Institute for Clinical and Economic Review, two country adaptations of the company model in the UK and the Netherlands, and another US publication. The main differences in methodological choices and their impact on cost-effectiveness results were assessed and further explored with sensitivity analyses using the Dutch model. To enable comparison between the economic evaluations, costs were converted to US dollars. Different methodological choices were made in the economic evaluations of VN resulting in large differences in the incremental cost-effectiveness ratio varying from US$79,618 to US$643,813 per QALY. The chosen duration of treatment effect, source of utility values, discount rate and model structure had the largest impact on the cost-effectiveness. This study underlines the findings from Drummond et al. that standard methods can be used to evaluate gene therapies. However, given uncertainty about (particularly long-term) outcomes of gene therapies, guidance is required on the acceptable extrapolation of treatment effect of gene therapies and on how to handle the uncertainty around this extrapolation in scenario and sensitivity analyses to aid health technology assessment research and align submissions of future gene therapies.

Early cost-utility analysis of tissue-engineered heart valves compared to bioprostheses in the aortic position in elderly patients.

OBJECTIVES: Aortic valve disease is the most frequent indication for heart valve replacement with the highest prevalence in elderly. Tissue-engineered heart valves (TEHV) are foreseen to have important advantages over currently used bioprosthetic heart valve substitutes, most importantly reducing valve degeneration with subsequent reduction of re-intervention. We performed early Health Technology Assessment of hypothetical TEHV in elderly patients (≥ 70 years) requiring surgical (SAVR) or transcatheter aortic valve implantation (TAVI) to assess the potential of TEHV and to inform future development decisions. METHODS: Using a patient-level simulation model, the potential cost-effectiveness of TEHV compared with bioprostheses was predicted from a societal perspective. Anticipated, but currently hypothetical improvements in performance of TEHV, divided in durability, thrombogenicity, and infection resistance, were explored in scenario analyses to estimate quality-adjusted life-year (QALY) gain, cost reduction, headroom, and budget impact. RESULTS: Durability of TEHV had the highest impact on QALY gain and costs, followed by infection resistance. Improved TEHV performance (- 50% prosthetic valve-related events) resulted in lifetime QALY gains of 0.131 and 0.043, lifetime cost reductions of €639 and €368, translating to headrooms of €3255 and €2498 per hypothetical TEHV compared to SAVR and TAVI, respectively. National savings in the first decade after implementation varied between €2.8 and €11.2 million (SAVR) and €3.2-€12.8 million (TAVI) for TEHV substitution rates of 25-100%. CONCLUSIONS: Despite the relatively short life expectancy of elderly patients undergoing SAVR/TAVI, hypothetical TEHV are predicted to be cost-effective compared to bioprostheses, commercially viable and result in national cost savings when biomedical engineers succeed in realising improved durability and/or infection resistance of TEHV.

Outcomes after surgery for functional tricuspid regurgitation: a systematic review and meta-analysis.

AIMS: This study aims to provide a contemporary overview of outcomes after tricuspid valve (TV) surgery for functional tricuspid regurgitation (TR). METHODS AND RESULTS: The literature was systematically searched for papers published between January 2005 and December 2017 reporting on clinical/echocardiographic outcomes after TV surgery for functional TR. A random effects meta-analysis was conducted for outcome variables, and late outcomes are visualized by pooled Kaplan-Meier curves. Subgroup analyses were performed for studies with a within-study comparison of suture vs. ring repair and flexible vs. rigid ring repair. Eighty-seven publications were included, encompassing 13 184 patients (mean age: 62.1 ± 11.8 years, 55% females). A mitral valve procedure was performed in 92% of patients. Pooled mean follow-up was 4.0 ± 2.8 years. Pooled early mortality was 3.9% (95% CI: 3.2-4.6), and late mortality rate was 2.7%/year (95% CI: 2.0-3.5), of which approximately half was cardiac-related 1.2%/year (95% CI: 0.8-1.9). Pooled risk of early moderate-to-severe TR at discharge was 9.4% (95% CI: 7.0-12.1). Late moderate-to-severe TR rate after discharge was 1.9%/year (95% CI: 1.0-3.5). Late reintervention rate was 0.3%/year (95% CI: 0.2-0.4). Mortality and overall (early and late) TR rate were comparable between suture vs. ring annuloplasty (14 studies), whereas overall TR rate was higher after flexible ring vs. rigid ring annuloplasty (6 studies) (7.5%/year vs. 3.9%/year, P = 0.002). CONCLUSION: This study shows that patients undergoing surgery for functional tricuspid regurgitation (FTR) have an acceptable early and late mortality. However, TR remains prevalent after surgery. The results of this study can be used to inform patients and clinicians about the expected outcome after surgery for FTR and can results serve as a benchmark for the performance of emerging transcatheter TV interventions.

Bioprosthetic Aortic Valve Replacement in Nonelderly Adults: A Systematic Review, Meta-Analysis, Microsimulation

Background To support decision-making in aortic valve replacement in nonelderly adults, we aim to provide a comprehensive overview of reported outcome after bioprosthetic aortic valve replacement and to translate this to age-specific patient outcome estimates. Methods and Results A systematic review was conducted for papers reporting clinical outcome after aortic valve replacement with currently available bioprostheses in patients with a mean age <55 years, published between January 1, 2000, and January 9, 2016. Pooled reported event rates and time-to-event data were pooled and entered into a microsimulation model to calculate life expectancy and lifetime event risk for the ages of 25, 35, 45, and 55 years at surgery. Nineteen publications were included, encompassing a total of 2686 patients with 21 117 patient-years of follow-up (pooled mean follow-up: 7.9±4.2 years). Pooled mean age at surgery was 50.7±11.0 years. Pooled early mortality risk was 3.30% (95% CI, 2.39-4.55), late mortality rate was 2.39%/y (95% CI, 1.13-2.94), reintervention 1.82%/y (95% CI, 1.31-2.52), structural valve deterioration 1.59%/y (95% CI, 1.21-2.10), thromboembolism 0.53%/y (95% CI, 0.42-0.67), bleeding 0.22%/y (95% CI, 0.16-0.32), endocarditis 0.48%/y (95% CI, 0.37-0.62), and 20-year pooled actuarial survival was 58.7% and freedom from reintervention was 29.0%. Median time to structural valve deterioration was 17.3 years and median time to all-cause first reintervention was 16.9 years. For a 45-year-old adult, for example, this translated to a microsimulation-based estimated life expectancy of 21 years (general population: 32 years) and lifetime risk of reintervention of 78%, structural valve deterioration 71%, thromboembolism 12%, bleeding 5%, and endocarditis 9%. Conclusions Aortic valve replacement with bioprostheses in young adults is associated with high structural valve deterioration and reintervention rates and low, though not absent, hazards of thromboembolism and bleeding. Foremostly, most patients will require one or more reinterventions during their lifetime and survival is impaired in comparison with the age- and sex-matched general population. Prosthesis durability remains the main concern in nonelderly patients.

What Is the Potential of Tissue-Engineered Pulmonary Valves in Children?

BACKGROUND: As a living heart valve substitute with growth potential and improved durability, tissue-engineered heart valves (TEHVs) may prevent reinterventions that are currently often needed in children with congenital heart disease. We performed early health technology assessment to assess the potential cost-effectiveness of TEHVs in children requiring right ventricular outflow tract reconstruction (RVOTR). METHODS: A systematic review and meta-analysis was conducted of studies reporting clinical outcome after RVOTR with existing heart valve substitutes in children (mean age ≤12 years or maximum age ≤21 years) published between January 1, 2000, and May 2, 2018. Using a patient-level simulation model, costs and effects of RVOTR with TEHVs compared with existing heart valve substitutes were assessed from a health care perspective applying a 10-year time horizon. Improvements in performance of TEHVs, divided in durability, thrombogenicity, and infection resistance, were explored to estimate quality-adjusted life year (QALY) gain, cost reduction, headroom, and budget impact associated with TEHVs. RESULTS: Five-year freedom from reintervention after RVOTR with existing heart valve substitutes was 46.1% in patients less than or equal to 2 years of age and 81.1% in patients greater than 2 years of age. Improvements in durability had the highest impact on QALYs and costs. In the improved TEHV performance scenario (durability ≥5 years and -50% other valve-related events), QALY gain was 0.074 and cost reduction was €10,378 per patient, translating to maximum additional costs of €11,856 per TEHV compared with existing heart valve substitutes. CONCLUSIONS: This study showed that there is room for improvement in clinical outcomes in children requiring RVOTR. If TEHVs result in improved clinical outcomes, they are expected to be cost-effective compared with existing heart valve substitutes.

Bioprosthetic aortic valve replacement in elderly patients: Meta-analysis and microsimulation.

OBJECTIVE: To support decision-making in aortic valve replacement (AVR) in elderly patients, we provide a comprehensive overview of outcome after AVR with bioprostheses. METHODS: A systematic review was conducted of studies reporting clinical outcome after AVR with bioprostheses in elderly patients (mean age ≥70 years; minimum age ≥65 years) published between January 1, 2000, to September 1, 2016. Reported event rates and time-to-event data were pooled and entered into a microsimulation model to calculate life expectancy and lifetime event risks. RESULTS: Forty-two studies reporting on 34 patient cohorts were included, encompassing a total of 12,842 patients with 55,437 patient-years of follow-up (pooled mean follow-up 5.0 ± 3.3 years). Pooled mean age was 76.5 ± 5.5 years. Pooled early mortality risk was 5.42% (95% confidence interval [CI], 4.49-6.55), thromboembolism rate was 1.83%/year (95% CI, 1.28-3.61), and bleeding rate was 0.75%/year (95% CI, 0.50-1.11). Structural valve deterioration (SVD) was based on pooled time to SVD data (Gompertz; shape: 0.124, rate: 0.003). For a 75-year-old patient, this translated to an estimated life expectancy of 9.8 years (general population: 10.2 years) and lifetime risks of bleeding of 7%, thromboembolism of 17%, and reintervention of 9%. CONCLUSIONS: The low risks of SVD and reintervention support the use of bioprostheses in elderly patients in need of AVR. The estimated life expectancy after AVR was comparable with the general population. The results of this study inform patients and clinicians about the expected outcomes after bioprosthetic AVR and thereby support treatment decision-making. Furthermore, our results can be used as a benchmark for long-term outcomes after transcatheter aortic valve implantation in patients who were eligible for surgery and other (future) alternative treatments (eg, tissue-engineered heart valves).

Beyond the clinical impact of aortic and pulmonary valve implantation: health-related quality of life, informal care and productivity†.

OBJECTIVES: Our aim was to provide estimates of patient-reported health-related quality of life (HRQoL), use of informal care and productivity in patients after surgical aortic and pulmonary valve replacement and transcatheter aortic valve implantation. METHODS: Consecutive cohorts of 1239 adult patients who had surgical aortic valve replacement or surgical pulmonary valve replacement and 433 patients who had transcatheter aortic valve implantation at 2 Dutch heart centres were cross-sectionally surveyed at a median time of 2.9 and 3.2 years after the intervention, respectively. The survey included questions on HRQoL (EQ-5D-5L and SF-12-v2), use of informal care and productivity in paid and unpaid work. All outcomes were compared with age and sex-matched individuals from the general population. RESULTS: The response rate was 56% (n = 687) of patients who had surgical valve replacement and 59% (n = 257) of those who had transcatheter aortic valve implantation. Compared with the general population, patients reported poorer HRQoL on physical health domains, whereas their scores were comparable for mental health domains. After a heart valve implantation, patients reported using informal care more frequently than the general population, but labour participation was comparable. Patients with late complications [antibiotic treatment for endocarditis (n = 4), stroke (n = 11), transient ischaemic attack (n = 15)] reported lower HRQoL, greater use of informal care and greater productivity loss than patients without complications. CONCLUSIONS: Patients who had aortic and pulmonary valve implantations experience relatively mild limitations in daily life compared to the general population. The consequences of a heart valve implantations beyond clinical outcomes should be considered to create realistic patient expectations of life after a heart valve implantation and unbiased resource allocation decisions at national levels.

The Ross Procedure: A Systematic Review, Meta-Analysis, and Microsimulation.

BACKGROUND: To support decision-making in aortic valve replacement in children and adults, we provide a comprehensive overview of outcome after the Ross procedure. METHODS AND RESULTS: A systematic search was conducted for publications reporting clinical outcome after the Ross procedure, published between January 1, 2000, and November 22, 2017. Reported event rates and time-to-event data were pooled and entered into a microsimulation model to calculate life expectancy and lifetime event risk. Ninety-nine publications were included (13 129 patients; total follow-up: 93 408 patient-years, pooled mean follow-up: 7.9±5.3 years). Pooled mean age at surgery was 9.4±5.5 years for children and 41.9±11.4 for adults. For children and adults, respectively, pooled early mortality risk was 4.19% (95% CI, 3.21-5.46) and 2.01% (95% CI, 1.44-2.82), late mortality rate was 0.54%/y (95% CI, 0.42-0.70) and 0.59%/y (95% CI, 0.46-0.76), autograft reintervention 1.28%/y (95% CI, 0.99-1.66) and 0.83%/y (95% CI, 0.68-1.01), and right ventricular outflow tract reintervention 1.97%/y (95% CI, 1.64-2.36) and 0.47%/y (95% CI, 0.37-0.59). Pooled thromboembolism and bleeding rates were low and comparable to the general population. Lifetime risks of autograft and right ventricular outflow tract reintervention were, respectively, 94% and 100% for children and 49% and 19% for a 45-year-old. Estimated life expectancy after surgery was 59 years for children (general population: 64 years) and 30 years for a 45 years old (general population: 31 years). CONCLUSIONS: Through excellent survival and avoidance of the burden of anticoagulation, the Ross procedure provides a unique opportunity for patients whose preferences do not align with the outcome provided by mechanical valve replacement and for growing children who also benefit from autograft diameter increase along with somatic growth. On the downside, almost all pediatric and many adult Ross patients will require a reintervention in their lifetime.

How much does a heart valve implantation cost and what are the health care costs afterwards?

Objective: In the era of limited healthcare budgets, healthcare costs of heart valve implantations need to be considered to inform cost-effectiveness analyses. We aimed to provide age group-specific costs estimates of heart valve implantations, related complications and other healthcare utilisation following the intervention. Methods: We performed retrospective analyses of healthcare costs of patients who had undergone heart valve implantations in 2010-2013 and controls using claims data from Dutch health insurers. Heart valve implantations included surgical valve replacement and transcatheter valve implantation in all heart valve positions. Patients were divided in four age groups. Control groups were created by taking random samples of the Dutch population stratified by age, gender, socioeconomic status and comorbidities. We applied non-parametric bootstrapping to address uncertainty of the cost estimates. The association of patient and intervention characteristics with costs was determined by (multilevel) generalised linear models. Results: The baseline characteristics of 18 903 patients and 188 925 controls were comparable. The annual healthcare costs were substantially higher for surgical heart valve replacement patients than for controls, especially in the year of heart valve implantation. Factors associated with increased annual healthcare costs for patients were older age, female gender, comorbidities, low socioeconomic status and complications. Conclusions: We provided a comprehensive overview of age group-specific incidence of heart valve implantations, subsequent survival and complications as well as associated healthcare costs of all patients in the Netherlands. Our results provide real-world costs estimates that can be used as a benchmark for costs of future innovative heart valve implantations.

Systematic review of model-based economic evaluations of heart valve implantations.

OBJECTIVE: To review the evidence on the cost-effectiveness of heart valve implantations generated by decision analytic models and to assess their methodological quality. METHODS: A systematic review was performed including model-based cost-effectiveness analyses of heart valve implantations. Study and model characteristics and cost-effectiveness results were extracted and the methodological quality was assessed using the Philips checklist. RESULTS: Fourteen decision-analytic models regarding the cost-effectiveness of heart valve implantations were identified. In most studies transcatheter aortic valve implantation (TAVI) was cost-effective compared to standard treatment (ST) in inoperable or high-risk operable patients (ICER range 18,421-120,779 €) and in all studies surgical aortic valve replacement (SAVR) was cost-effective compared to ST in operable patients (ICER range 14,108-40,944 €), but the results were not consistent on the cost-effectiveness of TAVI versus SAVR in high-risk operable patients (ICER range: dominant to dominated by SAVR). Mechanical mitral valve replacement (MVR) had the lowest costs per success compared to mitral valve repair and biological MVR. The methodological quality of the studies was moderate to good. CONCLUSION: This review showed that improvements can be made in the description and justification of methods and data sources, sensitivity analysis on extrapolation of results, subgroup analyses, consideration of methodological and structural uncertainty, and consistency (i.e. validity) of the models. There are several opportunities for future decision-analytic models of the cost-effectiveness of heart valve implantations: considering heart valve implantations in other valve positions besides the aortic valve, using a societal perspective, and developing patient-simulation models to investigate the impact of patient characteristics on outcomes.

Conceptual model for early health technology assessment of current and novel heart valve interventions.

OBJECTIVE: The future promises many technological advances in the field of heart valve interventions, like tissue-engineered heart valves (TEHV). Prior to introduction in clinical practice, it is essential to perform early health technology assessment. We aim to develop a conceptual model (CM) that can be used to investigate the performance and costs requirements for TEHV to become cost-effective. METHODS: After scoping the decision problem, a workgroup developed the draft CM based on clinical guidelines. This model was compared with existing models for cost-effectiveness of heart valve interventions, identified by systematic literature search. Next, it was discussed with a Delphi panel of cardiothoracic surgeons, cardiologists and a biomedical scientist (n=10). RESULTS: The CM starts with the valve implantation. If patients survive the intervention, they can remain alive without complications, die from non-valve-related causes or experience a valve-related event. The events are separated in early and late events. After surviving an event, patients can experience another event or die due to non-valve-related causes. Predictors will include age, gender, NYHA class, left ventricular function and diabetes. Costs and quality adjusted life years are to be attached to health conditions to estimate long-term costs and health outcomes. CONCLUSIONS: We developed a CM that will serve as foundation of a decision-analytic model that can estimate the potential cost-effectiveness of TEHV in early development stages. This supports developers in deciding about further development of TEHV and identifies promising interventions that may result in faster take-up in clinical practice by clinicians and reimbursement by payers.

Contemporary outcomes after surgical aortic valve replacement with bioprostheses and allografts: a systematic review and meta-analysis.

Many observational studies have reported outcomes after surgical aortic valve replacement (AVR), but there are no recent systematic reviews and meta-analyses including all available bioprostheses and allografts. The objective of this study is to provide a comprehensive and up-to-date overview of the outcomes after AVR with bioprostheses and allografts reported in the last 15 years. We conducted a systematic literature review (PROSPERO register: CRD42015017041) of studies published between 2000-15. Inclusion criteria were observational studies or randomized controlled trials reporting on outcomes of AVR with bioprostheses (stented or stentless) or allografts, with or without coronary artery bypass grafting (CABG) or valve repair procedure, with study population size n ≥ 30 and mean follow-up length ≥5 years. Fifty-four bioprosthesis studies and 14 allograft studies were included, encompassing 55 712 and 3872 patients and 349 840 and 32 419 patient-years, respectively. We pooled early mortality risk and linearized occurrence rates of valve-related events, reintervention and late mortality in a random-effects model. Sensitivity, meta-regression and subgroup analyses were performed to investigate the influence of outliers on the pooled estimates and to explore sources of heterogeneity. Funnel plots were used to investigate publication bias. Pooled early mortality risks for bioprostheses and allografts were 4.99% (95% confidence interval [CI], 4.44-5.62) and 5.03% (95% CI, 3.61-7.01), respectively. The late mortality rate was 5.70%/patient-year (95% CI, 4.99-5.62) for bioprostheses and 1.68%/patient-year (95% CI, 1.23-2.28) for allografts. Pooled reintervention rates for bioprostheses and allografts were 0.75%/patient-year (95% CI, 0.61-0.91) and 1.87%/patient-year (95% CI, 1.52-2.31), respectively. There was substantial heterogeneity in most outcomes. Meta-regression analyses identified covariates that could explain the heterogeneity: implantation period, valve type, patient age, gender, pre-intervention New York Heart Association class III/IV, concomitant CABG, study design and follow-up length. There is possible publication bias in all outcomes. This comprehensive systematic review and meta-analysis provides an overview of the outcomes after AVR with bioprostheses and allografts reported during the last 15 years. The results of this study can support patients and doctors in the prosthetic valve choice and can be used in microsimulation models to predict patient outcomes and estimate the cost-effectiveness of AVR with bioprostheses or allografts compared with current and future heart valve prostheses.

Exploring the variation in implementation of a COPD disease management programme and its impact on health outcomes: a post hoc analysis of the RECODE cluster randomised trial.

This study aims to (1) examine the variation in implementation of a 2-year chronic obstructive pulmonary disease (COPD) management programme called RECODE, (2) analyse the facilitators and barriers to implementation and (3) investigate the influence of this variation on health outcomes. Implementation variation among the 20 primary-care teams was measured directly using a self-developed scale and indirectly through the level of care integration as measured with the Patient Assessment of Chronic Illness Care (PACIC) and the Assessment of Chronic Illness Care (ACIC). Interviews were held to obtain detailed information regarding the facilitators and barriers to implementation. Multilevel models were used to investigate the association between variation in implementation and change in outcomes. The teams implemented, on average, eight of the 19 interventions, and the specific package of interventions varied widely. Important barriers and facilitators of implementation were (in)sufficient motivation of healthcare provider and patient, the high starting level of COPD care, the small size of the COPD population per team, the mild COPD population, practicalities of the information and communication technology (ICT) system, and hurdles in reimbursement. Level of implementation as measured with our own scale and the ACIC was not associated with health outcomes. A higher level of implementation measured with the PACIC was positively associated with improved self-management capabilities, but this association was not found for other outcomes. There was a wide variety in the implementation of RECODE, associated with barriers at individual, social, organisational and societal level. There was little association between extent of implementation and health outcomes.