Strategies for the management of hypercholesterolaemia: a systematic review of the cost-effectiveness literature

OBJECTIVE: To review research addressing the management of cholesterol in the prevention of coronary heart disease in order to assess the cost-effectiveness of such interventions. METHODS: A systematic review of economic evaluations identified through searches of MEDLINE and the Social Sciences Citation Index revealed 38 studies addressing the cost-effectiveness of cholesterol management. They were distinguished according to screening approaches, dietary advice and drug treatment. Most studies were not associated directly with clinical trial results, but adopted economic modelling approaches. RESULTS: Whilst there is general agreement among the majority of analyses, studies of cholesterol management concerned with screening strategies were extremely sensitive to changes in their assumptions; so much so that only a limited emphasis may be placed on specific cost-effectiveness ratios and the conclusions drawn from them. All studies considered direct costs, though many were limited to drug costs. The cost-effectiveness of primary prevention by cholesterol-lowering drugs is highly variable, depending on age at initiation of treatment and cardiovascular risk profile. Pharmacological intervention is least cost-effective in the young and the elderly. The cost-effectiveness of cholesterol-reducing agents improves when they are targeted at those at high risk. HMG-CoA reductase inhibitors are generally more effective and more cost-effective at reducing cholesterol-related coronary events than other medications. CONCLUSION: The methods and economic data upon which these studies are based need to be improved if robust policy conclusions are to be formulated.     

Reduction of Family Violence in Aboriginal Communities: A Systematic Review of Interventions and Approaches

Many efforts to reduce family violence are documented in the published literature. We conducted a systematic review of interventions intended to prevent family violence in Aboriginal communities. We retrieved studies published up to October 2009; 506 papers included one systematic review, two randomized controlled trials, and fourteen nonrandomized studies or reviews. Two reviews discussed interventions relevant to primary prevention (reducing the risk factors for family violence), including parenting, role modelling, and active participation. More studies addressed secondary prevention (where risk factors exist, reducing outbreaks of violence) such as restriction on the trading hours for take away alcohol and home visiting programs for high risk families. Examples of tertiary prevention (preventing recurrence) include traditional healing circles and group counselling. Most studies contributed a low level of evidence.     

Economic Evaluations of Remote Patient Monitoring for Chronic Disease: A Systematic Review

ObjectivesThis study aimed to systematically review and summarize economic evaluations of noninvasive remote patient monitoring (RPM) for chronic diseases compared with usual care.MethodsA systematic literature search identified economic evaluations of RPM for chronic diseases, compared with usual care. Searches of PubMed, Embase, CINAHL, and EconLit using keyword synonyms for RPM and economics identified articles published from up until September 2021. Title, abstract, and full-text reviews were conducted. Data extraction of study characteristics and health economic findings was performed. Article reporting quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards checklist.ResultsThis review demonstrated that the cost-effectiveness of RPM was dependent on clinical context, capital investment, organizational processes, and willingness to pay in each specific setting. RPM was found to be highly cost-effective for hypertension and may be cost-effective for heart failure and chronic obstructive pulmonary disease. There were few studies that investigated RPM for diabetes or other chronic diseases. Studies were of high reporting quality, with an average Consolidated Health Economic Evaluation Reporting Standards score of 81%. Of the final 34 included studies, most were conducted from the healthcare system perspective. Eighteen studies used cost-utility analysis, 4 used cost-effectiveness analysis, 2 combined cost-utility analysis and a cost-effectiveness analysis, 1 used cost-consequence analysis, 1 used cost-benefit analysis, and 8 used cost-minimization analysis.ConclusionsRPM was highly cost-effective for hypertension and may achieve greater long-term cost savings from the prevention of high-cost health events. For chronic obstructive pulmonary disease and heart failure, cost-effectiveness findings differed according to disease severity and there was limited economic evidence for diabetes interventions.     

Economic evaluation of lifestyle interventions for preventing diabetes and cardiovascular diseases

Lifestyle interventions (i.e., diet and/or physical activity) are effective in delaying or preventing the onset of diabetes and cardiovascular disease. However, policymakers must know the cost-effectiveness of such interventions before implementing them at the large-scale population level. This review discusses various issues (e.g., characteristics, modeling, and long-term effectiveness) in the economic evaluation of lifestyle interventions for the primary and secondary prevention of diabetes and cardiovascular disease. The diverse nature of lifestyle interventions, i.e., type of intervention, means of provision, target groups, setting, and methodology, are the main obstacles to comparing evaluation results. However, most lifestyle interventions are among the intervention options usually regarded as cost-effective. Diabetes prevention programs, such as interventions starting with targeted or universal screening, childhood obesity prevention, and community-based interventions, have reported favorable cost-effectiveness ratios.     

Systematic review of rotavirus vaccination cost-effectiveness in high income settings utilising dynamic transmission modelling techniques

PurposeThis systematic review presents cost-effectiveness studies of rotavirus vaccination in high-income settings based on dynamic transmission modelling to inform policy decisions about implementing rotavirus vaccination programmes.MethodsWe searched CEA Registry, MEDLINE, Embase, Health Technology Assessment Database, Scopus, and the National Health Service Economic Evaluation Database for studies published since 2002. Full economic evaluation studies based on dynamic transmission models, focusing on high-income countries, live oral rotavirus vaccine and children ≤ 5 years of age were eligible for inclusion. Included studies were appraised for quality and risk of bias using the Consensus on Health Economic Criteria (CHEC) list and the Philips checklist. The review protocol was prospectively registered with PROSPERO (CRD42020208406).ResultsA total of four economic evaluations were identified. Study settings included England and Wales, France, Norway, and the United States. All studies compared either pentavalent or monovalent rotavirus vaccines to no intervention. All studies were cost-utility analyses that reported incremental cost per quality-adjusted life year (QALY) gained. Included studies consistently concluded that rotavirus vaccination is cost-effective compared with no vaccination relative to the respective country’s willingness to pay threshold when herd protection benefits are incorporated in the modelling framework.ConclusionsRotavirus vaccination was found to be cost-effective in all identified studies that used dynamic transmission models in high-income settings where child mortality rates due to rotavirus gastroenteritis are close to zero. Previous systematic reviews of economic evaluations considered mostly static models and had less conclusive findings than the current study. This review suggests that modelling choices influence cost-effectiveness results for rotavirus vaccination. Specifically, the review suggests that dynamic transmission models are more likely to account for the full impact of rotavirus vaccination than static models in cost-effectiveness analyses.     

Child maltreatment prevention: a systematic review of reviews

Objective

To synthesize recent evidence from systematic and comprehensive reviews on the effectiveness of universal and selective child maltreatment prevention interventions, evaluate the methodological quality of the reviews and outcome evaluation studies they are based on, and map the geographical distribution of the evidence.

Methods

A systematic review of reviews was conducted. The quality of the systematic reviews was evaluated with a tool for the assessment of multiple systematic reviews (AMSTAR), and the quality of the outcome evaluations was assessed using indicators of internal validity and of the construct validity of outcome measures.

Findings

The review focused on seven main types of interventions: home visiting, parent education, child sex abuse prevention, abusive head trauma prevention, multi-component interventions, media-based interventions, and support and mutual aid groups. Four of the seven – home-visiting, parent education, abusive head trauma prevention and multi-component interventions – show promise in preventing actual child maltreatment. Three of them – home visiting, parent education and child sexual abuse prevention – appear effective in reducing risk factors for child maltreatment, although these conclusions are tentative due to the methodological shortcomings of the reviews and outcome evaluation studies they draw on. An analysis of the geographical distribution of the evidence shows that outcome evaluations of child maltreatment prevention interventions are exceedingly rare in low- and middle-income countries and make up only 0.6% of the total evidence base.

Conclusion

Evidence for the effectiveness of four of the seven main types of interventions for preventing child maltreatment is promising, although it is weakened by methodological problems and paucity of outcome evaluations from low- and middle-income countries.     

Economic evaluation and catheter-related bloodstream infections

Catheter-related bloodstream infections are a serious problem. Many interventions reduce risk, and some have been evaluated in cost-effectiveness studies. We review the usefulness and quality of these economic studies. Evidence is incomplete, and data required to inform a coherent policy are missing. The cost-effectiveness studies are characterized by a lack of transparency, short time-horizons, and narrow economic perspectives. Data quality is low for some important model parameters. Authors of future economic evaluations should aim to model the complete policy and not just single interventions. They should be rigorous in developing the structure of the economic model, include all relevant economic outcomes, use a systematic approach for selecting data sources for model parameters, and propagate the effect of uncertainty in model parameters on conclusions. This will inform future data collection and improve our understanding of the economics of preventing these infections.     

The Effects of Isocaloric Intermittent Fasting vs Daily Caloric Restriction on Weight Loss and Metabolic Risk Factors for Noncommunicable Chronic Diseases: A Systematic Review of Randomized Controlled or Comparative Trials

BackgroundIntermittent fasting (IF) has gained favor as an alternative regimen to daily caloric restriction (DCR). Therefore, there is a need for systematic reviews of randomized controlled/comparison trials examining the effects of isocaloric IF vs DCR on metabolic risk factors for noncommunicable chronic diseases.ObjectiveTo systematically investigate the effects of isocaloric IF vs DCR on metabolic risk factors for noncommunicable chronic diseases in adults with overweight and obesity.MethodsFive online databases (PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar) were searched for articles published from January 2000 through April 2022. The updated Cochrane Risk of Bias Assessment tool for randomized controlled/comparison trials was used to assess risk of bias in the included studies. This review includes randomized controlled/comparison trials with matched energy intakes (isocaloric) between IF and DCR among adults with overweight and obesity with ≥8-week durations, that assessed risk factors related to obesity and for diabetes, cardiovascular diseases, and cancers.ResultsThirteen randomized controlled/comparison trials with matched energy intakes (isocaloric) between IF and DCR were identified. The effects of IF on weight loss and metabolic risk markers of diabetes, cardiovascular diseases, and cancers were varied but generally comparable with DCR. IF (4:3 and 5:2 diets) was superior to DCR for improving insulin sensitivity in two studies. Reductions in body fat were significantly greater with IF (5:2 diet and time-restricted eating) than DCR in two studies of isocaloric diets.ConclusionsWith matched energy intakes, IF interventions produced similar beneficial effects for weight loss and chronic disease risk factors compared with DCR. Very limited evidence suggests that IF may be more effective vs DCR for fat loss and insulin sensitivity, but conclusions cannot be drawn based on the current evidence. Future clinical studies with larger populations and longer durations are needed for further elucidation of any potential effects of IF regimens for prevention of noncommunicable chronic diseases.     

Economic Evaluation of Interventions to Address Opioid Misuse: A Systematic Review of Methods Used in Simulation Modeling Studies

ObjectivesSeveral evidence-based interventions exist for people who misuse opioids, but there is limited guidance on optimal intervention selection. Economic evaluations using simulation modeling can guide the allocation of resources and help tackle the opioid crisis. This study reviews methods employed by economic evaluations using computer simulations to investigate the health and economic effects of interventions meant to address opioid misuse.MethodsWe conducted a systematic mapping review of studies that used simulation modeling to support the economic evaluation of interventions targeting prevention, treatment, or management of opioid misuse or its direct consequences (ie, overdose). We searched 6 databases and extracted information on study population, interventions, costs, outcomes, and economic analysis and modeling approaches.ResultsEighteen studies met the inclusion criteria. All of the studies considered only one segment of the continuum of care. Of the studies, 13 evaluated medications for opioid use disorder, and 5 evaluated naloxone distribution programs to reduce overdose deaths. Most studies estimated incremental cost per quality-adjusted life-years and used health system and/or societal perspectives. Models were decision trees (n = 4), Markov (n = 10) or semi-Markov models (n = 3), and microsimulations (n = 1). All of the studies assessed parameter uncertainty though deterministic and/or probabilistic sensitivity analysis, 4 conducted formal calibration, only 2 assessed structural uncertainty, and only 1 conducted expected value of information analyses. Only 10 studies conducted validation.ConclusionsFuture economic evaluations should consider synergies between interventions and examine combinations of interventions to inform optimal policy response. They should also more consistently conduct model validation and assess the value of further research.     

Systematic reviews of economic evaluations: utility or futility?

Systematic reviews of studies of effectiveness are the centrepiece of evidence‐based medicine and policy making. Increasingly, systematic reviews of economic evaluations are also an expected input into much evidence‐based policy making, with some health economists even calling for ‘an economics approach to systematic review’. This paper questions the value of conducting systematic reviews of economic evaluations to inform decision making in health care. It argues that the value of systematic reviews of economic evaluations is usually undermined by three things. Firstly, compared with effectiveness studies, there is a much wider range of factors that limit the generalisability of cost–effectiveness results, over time and between health systems and service settings, including the context‐dependency of resource use and opportunity costs, and different decision contexts and budget constraints. Secondly, because economic evaluations are more explicitly intended to be decision‐informing, the requirements for generalisability take primacy, and considerations of internal validity become more secondary. Thirdly, since one of the two main forms of economic evaluation – decision analytic modelling – is itself a well‐developed method of evidence synthesis, in most cases the need for a comprehensive systematic review of previous economic evaluations of a particular health technology or policy choice is unwarranted. I conclude that apparent ‘meta‐analytic expectations’ for clear and widely applicable cost–effectiveness conclusions from systematic reviews of economic evaluations are optimistic and generally futile. For more useful insights and knowledge from previous economic studies in evidence‐based policy making, a more limited range of reasons for conducting systematic reviews of health economic studies is proposed. Copyright © 2009 John Wiley & Sons, Ltd.     

Does physical activity modify the risk of obesity for type 2 diabetes: a review of epidemiological data

Obesity and physical inactivity are both risk factors for type 2 diabetes. Since they are strongly associated, it has been suggested that they might interact. In this study, we summarized the evidence on this interaction by conducting a systematic review. Two types of interaction have been discerned, statistical and biological interaction, which could give different results. Therefore, we calculated both types of interaction for the studies in our review. Cohort studies, published between 1999 and 2008, that investigated the effects of obesity and physical activity on the risk of type 2 diabetes were included. We calculated both biological and statistical interaction in these studies. Eight studies were included of which five were suitable to calculate interaction. All studies showed positive biological interaction, meaning that the joint effect was more than the sum of the individual effects. However, there was inconsistent statistical interaction; in some studies the joint effect was more than the product of the individual effects, in other studies it was less. The results show that obesity and physical inactivity interact on an additive scale. This means that prevention of either obesity or physical inactivity, not only reduces the risk of diabetes by taking away the independent effect of this factor, but also by preventing the cases that were caused by the interaction between both factors. Furthermore, this review clearly showed that results can differ depending on what method is used to assess interaction.     

Parenting interventions: a systematic review of the economic evidence

Conduct disorder (CD) places huge costs on the individual, family and society. Parenting programmes can reduce CD symptomatology, but economic evaluations of their cost-effectiveness are rarely undertaken. The objective of this paper was to conduct the first specific systematic review of the published economic evidence of parenting programmes as a means to support families with children with or at risk of developing CD. A systematic search of 12 electronic databases was conducted. We identified 93 papers, of which six fulfilled the inclusion criteria. The search found one review article, mainly focusing upon clinical evidence with secondary focus on cost-effectiveness, one cost-effectiveness study, two partial economic evaluations and two cost studies. The costs of group parenting programme delivery ranged from ￡629.00 to ￡3839.00. Cost-effectiveness was influenced by intervention type and delivery method, i.e. individual versus group programme. The review highlights a need for a more standardized approach towards the comparison of the cost-effectiveness of parent programmes. In future studies it may be helpful to adopt a 'complex intervention approach', exploring in detail the attribution of cause and effect, the role of socio-economic setting and ripple effects, e.g. benefits to other family members.     

Kosteneffektivit?t der Prim?rpr?vention des Typ-2-Diabetes

Background

Worldwide the number of adults suffering from type 2 diabetes mellitus (T2DM) is increasing. Since the disease represents a large burden for patients and society, its primary prevention is a major issue of public health. There is strong evidence that T2DM can be delayed or prevented by adequate interventions (pharmacological and lifestyle interventions) in individuals with pre-diabetes. However, the question emerges whether the implementation of these interventions is cost-effective or not.

Objective

This work presents the results of a systematic review of studies concerning the cost-effectiveness of interventions targeting primary prevention of T2DM.

Results

Eleven cost-effectiveness analyses were identified and included in this review. In all of them primary prevention of T2DM was shown to be potentially cost-effective. Differences in reported cost-effectiveness ratios could be explained by varying study design and target population.     

Parent Involvement in Diet or Physical Activity Interventions to Treat or Prevent Childhood Obesity: An Umbrella Review

Parents substantially influence children’s diet and physical activity behaviors, which consequently impact childhood obesity risk. Given this influence of parents, the objective of this umbrella review was to synthesize evidence on effects of parent involvement in diet and physical activity treatment and prevention interventions on obesity risk among children aged 3–12 years old. Ovid/MEDLINE, Elsevier/Embase, Wiley/Cochrane Library, Clarivate/Web of Science, EBSCO/CINAHL, EBSCO/PsycInfo, and Epistemonikos.org were searched from their inception through January 2020. Abstract screening, full-text review, quality assessment, and data extraction were conducted independently by at least two authors. Systematic reviews and meta-analyses of diet and physical activity interventions that described parent involvement, included a comparator/control, and measured child weight/weight status as a primary outcome among children aged 3–12 years old were included. Data were extracted at the level of the systematic review/meta-analysis, and findings were narratively synthesized. Of 4158 references identified, 14 systematic reviews and/or meta-analyses (eight treatment focused and six prevention focused) were included and ranged in quality from very low to very high. Our findings support the inclusion of a parent component in both treatment and prevention interventions to improve child weight/weight status outcomes. Of note, all prevention-focused reviews included a school-based component. Evidence to define optimal parent involvement type and duration and to define the best methods of involving parents across multiple environments (e.g., home, preschool, school) was inadequate and warrants further research. PROSPERO registration: CRD42018095360.     

The cost-effectiveness of preventing mother-to-child transmission of HIV in low- and middle-income countries: systematic review

Background

Although highly effective prevention interventions exist, the epidemic of paediatric HIV continues to challenge control efforts in resource-limited settings. We reviewed the cost-effectiveness of interventions to prevent mother-to-child transmission (MTCT) of HIV in low- and middle-income countries (LMICs). This article presents syntheses of evidence on the costs, effects and cost-effectiveness of HIV MTCT strategies for LMICs from the published literature and evaluates their implications for policy and future research.

Methods

Candidate studies were identified through a comprehensive database search including PubMed, Embase, Cochrane Library, and EconLit restricted by language (English or French), date (January 1st, 1994 to January 17^th, 2011) and article type (original research). Articles reporting full economic evaluations of interventions to prevent or reduce HIV MTCT were eligible for inclusion. We searched article bibliographies to identify additional studies. Two authors independently assessed eligibility and extracted data from studies retained for review. Study quality was appraised using a modified BMJ checklist for economic evaluations. Data were synthesised in narrative form.

Results

We identified 19 articles published in 9 journals from 1996 to 2010, 16 concerning sub-Saharan Africa. Collectively, the articles suggest that interventions to prevent paediatric infections are cost-effective in a variety of LMIC settings as measured against accepted international benchmarks. In concentrated epidemics where HIV prevalence in the general population is very low, MTCT strategies based on universal testing of pregnant women may not compare well against cost-effectiveness benchmarks, or may satisfy formal criteria for cost-effectiveness but offer a low relative value as compared to competing interventions to improve population health.

Conclusions and Recommendations

Interventions to prevent HIV MTCT are compelling on economic grounds in many resource-limited settings and should remain at the forefront of global HIV prevention efforts. Future cost-effectiveness analyses can help to ensure that pMTCT interventions for LMICs reach their full potential by focussing on unanswered questions in four areas: local assessment of rapidly evolving HIV MTCT options; strategies to improve coverage and reach underserved populations; evaluation of a more comprehensive set of MTCT approaches including primary HIV prevention and reproductive counselling; integration of HIV MTCT and other sexual and reproductive health services.     

Scientific Evidence of Interventions Using the Mediterranean Diet: A Systematic Review

The Mediterranean Diet has been associated with greater longevity and quality of life in epidemiological studies, the majority being observational. The application of evidence-based medicine to the area of public health nutrition involves the necessity of developing clinical trials and systematic reviews to develop sound recommendations. The purpose of this study was to analyze and review the experimental studies on Mediterranean diet and disease prevention. A systematic review was made and a total of 43 articles corresponding to 35 different experimental studies were selected. Results were analyzed for the effects of the Mediterranean diet on lipoproteins, endothelial resistance, diabetes and antioxidative capacity, cardiovascular diseases, arthritis, cancer, body composition, and psychological function. The Mediterranean diet showed favorable effects on lipoprotein levels, endothelium vasodilatation, insulin resistance, metabolic syndrome, antioxidant capacity, myocardial and cardiovascular mortality, and cancer incidence in obese patients and in those with previous myocardial infarction. Results disclose the mechanisms of the Mediterranean diet in disease prevention, particularly in cardiovascular disease secondary prevention, but also emphasize the need to undertake experimental research and systematic reviews in the areas of primary prevention of cardiovascular disease, hypertension, diabetes, obesity, infectious diseases, age-related cognitive impairment, and cancer, among others. Interventions should use food scores or patterns to ascertain adherence to the Mediterranean diet. Further experimental research is needed to corroborate the benefits of the Mediterranean diet and the underlying mechanisms, and in this sense the methodology of the ongoing PREDIMED study is explained.     

Valuing the Health States Associated with Chlamydia trachomatis Infections and Their Sequelae: A Systematic Review of Economic Evaluations and Primary Studies

ObjectivesEconomic evaluations of interventions to prevent and control sexually transmitted infections such as Chlamydia trachomatis are increasingly required to present their outcomes in terms of quality-adjusted life-years using preference-based measurements of relevant health states. The objectives of this study were to critically evaluate how published cost-effectiveness studies have conceptualized and valued health states associated with chlamydia and to examine the primary evidence available to inform health state utility values (HSUVs).MethodsA systematic review was conducted, with searches of six electronic databases up to December 2012. Data on study characteristics, methods, and main results were extracted by using a standard template.ResultsNineteen economic evaluations of relevant interventions were included. Individual studies considered different health states and assigned different values and durations. Eleven studies cited the same source for HSUVs. Only five primary studies valued relevant health states. The methods and viewpoints adopted varied, and different values for health states were generated.ConclusionsLimitations in the information available about HSUVs associated with chlamydia and its complications have implications for the robustness of economic evaluations in this area. None of the primary studies could be used without reservation to inform cost-effectiveness analyses in the United Kingdom. Future debate should consider appropriate methods for valuing health states for infectious diseases, because recommended approaches may not be suitable. Unless we adequately tackle the challenges associated with measuring and valuing health-related quality of life for patients with chlamydia and other infectious diseases, evaluating the cost-effectiveness of interventions in this area will remain problematic.     

Economic Evaluations of Guideline-Based or Strategic Interventions for the Prevention or Treatment of Chronic Wounds

Background

Costs of chronic wound care are significant, but systematic reviews of cost-effectiveness studies regarding guideline-based or strategic interventions are scarce.

Objectives

Our objectives were to assess/compare the cost effectiveness of new interventions/systems designed to improve the prevention/treatment of chronic wounds in adult populations against current care and provide decision makers with information on which to base future interventions for chronic wound management.

Data Sources

Data sources included PubMed, Scopus, HTA, and NHS EED.

Study Eligibility Criteria, Participants, and Interventions

We included comparative health economic evaluations of interventions published in English designed to prevent or treat adult chronic wounds that were guideline-based or strategic in nature and from which an incremental cost-effectiveness ratio or incremental net health benefit was reported or could be calculated.

Study Appraisal and Synthesis Methods

Study and model characteristics and outcomes were extracted into pre-designed tables. Quality assessment of studies was based on literature-reported methods. Studies were assigned strength of evidence ratings and recommendation level for decision makers.

Results

A total of 16 health economic evaluations were included, of which ten were trial based and six were wholly model based. Only three studies had high, and five studies moderate, strength of evidence and were recommended for decision makers. All studies had some shortcomings regarding time horizon, costs, effectiveness units, and methodological reporting. Two studies had major flaws.

Limitations

Limitations include missed studies published in non-English languages or not cited in searched databases; judgment bias in assessing studies.

Conclusions and Implications of Key Findings

Few well conducted cost-effectiveness studies exist to guide decision makers regarding guideline-based or strategic interventions for chronic wounds.     

Cost-effectiveness of pneumococcal polysaccharide vaccination in adults: A systematic review of conclusions and assumptions

Streptococcus pneumoniae infections in adults are associated with substantial morbidity, mortality, and costs. A literature review was conducted to identify strengths and limitations of the cost-effectiveness of pneumococcal polysaccharide vaccine studies. A comparative analysis of the impact of model parameters on cost-effectiveness ratios was complemented by systematic assessment of the studies. We identified 11 economic evaluations of pneumococcal polysaccharide vaccine (PPV-23) in adults. In general, all 11 studies found that vaccination with PPV-23 is a cost-effective, and in some cases a cost-saving strategy for the prevention of invasive pneumococcal disease (IPD). The systematic assessment indicated that the results of the cost-effectiveness studies of PPV-23 are influenced by the values applied to vaccine efficacy, IPD incidence and case-fatality.