Evidence-based decision-making in infectious diseases epidemiology, prevention and control: matching research questions to study designs and quality appraisal tools

Interpretation of coefficients in segmented regression for interrupted time series analyses

Background Segmented regression, a common model for interrupted time series (ITS) analysis, primarily utilizes two equation parametrizations. Interpretations of coefficients vary between the two segmented regression parametrizations, leading to occasional user misinterpretations. Methods To illustrate differences in coefficient interpretation between two common parametrizations of segmented regression in ITS analysis, we derived analytical results and present an illustration evaluating the impact of a smoking regulation policy in Italy using a publicly accessible dataset. Estimated coefficients and their standard errors were obtained using two commonly used parametrizations for segmented regression with continuous outcomes. We clarified coefficient interpretations and intervention effect calculations. Results Our investigation revealed that both parametrizations represent the same model. However, due to differences in parametrization, the immediate effect of the intervention is estimated differently under the two approaches. The key difference lies in the interpretation of the coefficient related to the binary indicator for intervention implementation, impacting the calculation of the immediate effect. Conclusions Two common parametrizations of segmented regression represent the same model but have different interpretations of a key coefficient. Researchers employing either parametrization should exercise caution when interpreting coefficients and calculating intervention effects.

Implementation approaches for leprosy prevention with single-dose rifampicin: A support tool for decision making

BACKGROUND

In the past 15 years, the decline in annually detected leprosy patients has stagnated. To reduce the transmission of Mycobacterium leprae, the World Health Organization recommends single-dose rifampicin (SDR) as post-exposure prophylaxis (PEP) for contacts of leprosy patients. Various approaches to administer SDR-PEP have been piloted. However, requirements and criteria to select the most suitable approach were missing. The aims of this study were to develop an evidence-informed decision tool to support leprosy programme managers in selecting an SDR-PEP implementation approach, and to assess its user-friendliness among stakeholders without SDR-PEP experience.

METHODOLOGY

The development process comprised two phases. First, a draft tool was developed based on a literature review and semi-structured interviews with experts from various countries, organisations and institutes. This led to: an overview of existing SDR-PEP approaches and their characteristics; understanding the requirements and best circumstances for these approaches; and, identification of relevant criteria to select an approach. In the second phase the tool's usability and applicability was assessed, through interviews and a focus group discussion with intended, inexperienced users; leprosy programme managers and non-governmental organization (NGO) staff.

PRINCIPAL FINDINGS

Five SDR-PEP implementation approaches were identified. The levels of endemicity and stigma, and the accessibility of an area were identified as most relevant criteria to select an approach. There was an information gap on cost-effectiveness, while successful implementation depends on availability of resources. Five basic requirements, irrespective of the approach, were identified: stakeholder support; availability of medication; compliant health system; trained health staff; and health education. Two added benefits of the tool were identified: its potential value for advocacy and for training.

CONCLUSION

An evidence-informed SDR-PEP decision tool to support the selection of implementation approaches for leprosy prevention was developed. While the tool was evaluated by potential users, more research is needed to further improve the tool, especially health-economic studies, to ensure efficient and cost-effective implementation of SDR-PEP.

Hyperbaric Oxygenation in the Treatment of Fournier's Gangrene: A Systematic Review

INTRODUCTION

Fournier's gangrene (FG) is a sporadic, life-threatening, necrotizing infection affecting the perineum, perineal region, and genitals. Hyperbaric oxygenation (HBO) improves tissue perfusion and promotes angiogenesis and collagen synthesis. Despite these positive effects of HBO, the indication and the effects on outcome as adjunct therapy in FG remain controversial. Consequently, we decided to perform a systematic review to compare the treatment of FG with or without the use of HBO as an adjunct therapy.

MATERIALS AND METHODS

We performed a systematic review following the recommendations provided in the Cochrane Handbook of systematic Reviews and the PRISMA reporting guidelines. Due to the paucity of data and a suspected lack of randomized controlled trials, we considered all the available information for this systematic review.

RESULTS

The literature search for primary studies yielded 79 results. Finally, 13 studies were considered, which included a total of 376 patients with FG, of whom 202 received HBO therapy. Five of these studies had a retrospective case-control design. However, these 5 studies included a total of 319 patients; 145 of these patients were treated with adjunct HBO therapy. Overall, this leads to a mortality rate of 16.6% in the HBO group and 25.9% in the non-HBO group. Overall, risk of bias was assessed as moderate to high.

CONCLUSIONS

We conclude that despite the risk of bias, HBO has potential as an adjunct in FG treatment, but it is challenging to carry out further studies, mainly due to the rareness of FG and availability of HBO.

Leflunomide in the treatment of BK polyomavirus associated nephropathy in kidney transplanted patients - A systematic review

BK polyomavirus (BKPyV) associated nephropathy (BKVAN) is seen in about 5% of renal transplant patients and can lead to chronic graft failure or graft loss. No effective therapy is available. Leflunomide has shown promising results in BKVAN. We performed a systematic review about the use of leflunomide for the treatment of BKVAN. The recommendations of the Cochrane Handbook of systematic Reviews were followed. Due to different study designs and endpoints no meta-analysis was performed. The literature search for primary studies yielded 274 results. Finally, twelve studies were included with a total of 267 patients. Clearance of BKPyV viremia was reported in 33.3% to 92.3% of cases and 27 graft losses (10.1%). The included studies were very heterogeneous, especially in terms of leflunomide dosing. Pharmacokinetics seem to have an important impact on the efficacy of leflunomide in BKVAN. There was no correlation between leflunomide serum levels and virus reduction. New adverse events of leflunomide have been described, e.g. haemolytic anaemia and thrombotic microangiopathy. Overall, the risk of bias in the studies was assessed as high and the quality of evidence was rated low. The role of leflunomide in BKVAN remains unclear, but further studies seem reasonable and should address pharmacokinetic aspects.

Immune surveillance for vaccine-preventable diseases

INTRODUCTION

Immunesurveillance is an important tool to monitor the protection of the population against vaccine-preventable diseases, which is currently mostly based on the detection of specific serum antibodies. However, the landscape of immune surveillance is changing, driven by emerging and evolving pathogens, changes in the age distribution of the population and scientific understanding of protective immunity, necessitating a comprehensive review.

AREAS COVERED

To anticipate these changes, reliable and high-throughput detection of antibody levels is desired to enable screening in larger population settings. Antibody levels alone do not always equate with protection and may require additional functional testing of the antibodies or immune cell-based assays. In addition, the location (systemic or locally mucosal) of the infection and whether the antibodies are induced through infection or vaccination have implications for both immune protection and assessing immune status.

EXPERT COMMENTARY

In order to perform multicenter studies on many samples for multiple antigens, more validated reference materials and wider adoption of high-throughput techniques are needed. The field of serosurveillance will also benefit from better correlates of protection and understanding of (local) mechanisms of protection. Here we give an overview of the current state-of-the-art of serosurveillance and how the field could move forward.

Antimicrobial Stewardship Programs in Long-Term Care Settings: A Meta-Analysis and Systematic Review

BACKGROUND

Antimicrobial stewardship programs have been established in hospitals, but less studied in long‐term care facilities (LTCFs), a setting with unique challenges related to patient populations and available resources. This systematic review sought to provide a comprehensive assessment of antimicrobial stewardship interventions implemented in LTCFs, using meta‐analysis to examine their impact on overall antimicrobial use.

METHODS

Electronic searches of MEDLINE, Embase, and CINAHL (1990 to July 2018) identified any antimicrobial stewardship interventions in LTCFs, with no restriction on patient population, study design, or outcomes. Intervention components were categorized using the Cochrane Effective Practice and Organization of Care taxonomy on implementation strategies. Random‐effects meta‐analysis used ratio of means to facilitate pooling of different metrics of antimicrobial use.

RESULTS

Eighteen studies (one randomized controlled trial [RCT], four cluster RCTs, four controlled pre/post studies, and nine uncontrolled pre/post studies) met inclusion, using 13 different antimicrobial stewardship intervention strategies; 15 studies used multifaceted (maximum, seven; median, four) interventions. The three most commonly implemented strategies were educational materials, educational meetings, and guideline implementation. Intervention labor intensity and resource requirements varied considerably among interventions. Meta‐analysis of 11 studies demonstrated that antimicrobial stewardship strategies were associated with a 14% reduction in overall antimicrobial use (95% confidence interval = −8% to −20%; P < .0001), with similar results by study design but high heterogeneity (I² = 86%) for the uncontrolled pre/post study subgroup and no heterogeneity (I² = 0%) for the cluster RCT and controlled pre/post study subgroups. Funnel plot analysis suggested publication bias, with a lack of publication of smaller studies showing increased antibiotic use.

CONCLUSION

Antimicrobial stewardship strategies implemented in long‐term care vary considerably in design and resource intensity, but collectively suggest potential to reduce antimicrobial use in this challenging setting. J Am Geriatr Soc 67:392–399, 2019.

Comparison of intravenous or intravesical cidofovir in the treatment of BK polyomavirus-associated hemorrhagic cystitis following adult allogeneic stem cell transplantation-A systematic review

INTRODUCTION

BK polyomavirus can lead to hemorrhagic cystitis (BKPyV-HC) in allogeneic stem cell transplantation and therefore to increased morbidity. No causal therapy has been established yet. Cidofovir (CDV) is a nucleotide analog of cytosine that is active against various DNA viruses and it has been described for therapy of BKPyV-HC using 2 admission routes: intravenous and intravesical.

METHODS

We performed a systematic review regarding the comparison of intravenous or intravesical cidofovir in the treatment of BKPyV-HC following adult allogeneic stem cell transplantation. Since there is a lack of randomized controlled trials, we considered all kinds of studies for this review. Due to heterogeneity of the data, we were not able to perform a meta-analysis, so the results are shown descriptively.

RESULTS

The literature search for primary studies yielded 232 results. Finally, 9 studies where considered which included a total of 189 adult patients with BKPyV-HC after allogeneic stem cell transplantation. We could only identify retrospective studies for this review. A total of 172 patients received intravenous CDV, 17 patients received intravesical CDV, and 2 patients received CDV in both admission routes. In 68.0% of the cases, a complete response for intravenous CDV was documented and in 88.2% for intravesical CDV. Interestingly, no kidney toxicity was mentioned in intravesical CDV. 9.3% of the intravenously treated patients had renal failure.

CONCLUSION

There is only weak evidence for the use of CDV. The intravesical admission route should be further investigated because of a good toxicity profile.

PRECEPT: an evidence assessment framework for infectious disease epidemiology, prevention and control

Decisions in public health should be based on the best available evidence, reviewed and appraised using a rigorous and transparent methodology. The Project on a Framework for Rating Evidence in Public Health (PRECEPT) defined a methodology for evaluating and grading evidence in infectious disease epidemiology, prevention and control that takes different domains and question types into consideration. The methodology rates evidence in four domains: disease burden, risk factors, diagnostics and intervention. The framework guiding it has four steps going from overarching questions to an evidence statement. In step 1, approaches for identifying relevant key areas and developing specific questions to guide systematic evidence searches are described. In step 2, methodological guidance for conducting systematic reviews is provided; 15 study quality appraisal tools are proposed and an algorithm is given for matching a given study design with a tool. In step 3, a standardised evidence-grading scheme using the Grading of Recommendations Assessment, Development and Evaluation Working Group (GRADE) methodology is provided, whereby findings are documented in evidence profiles. Step 4 consists of preparing a narrative evidence summary. Users of this framework should be able to evaluate and grade scientific evidence from the four domains in a transparent and reproducible way.

Molecular epidemiology of fluoroquinolone resistant Salmonella in Africa: A systematic review and meta-analysis

BACKGROUND

Wide-ranging evidence on the occurrence of fluoroquinolone (FQ) resistance genetic determinants in African Salmonella strains is not available. The main objectives of this study were to assess the heterogeneity, estimate pooled proportions and describe the preponderance of FQ-resistance determinants in typhoidal and non-typhoidal Salmonella (NTS) isolates of Africa.

METHODS

Genetic and phenotypic data on 6103 Salmonella isolates were considered. Meta- and frequency analyses were performed depending on the number of studies by category, number of isolates and risks of bias. A random effects model was used to assess heterogeneity and estimate pooled proportions. Relative and cumulative frequencies were calculated to describe the overall preponderance of FQ-resistance determinants in quinolone resistant isolates.

RESULTS

The pooled proportion of gyrA mutants (Salmonella enterica serovar Typhi, Salmonella enterica serovar Typhimurium, and Salmonella enterica serovar Enteritidis) was estimated at 5.7% (95% Confidence interval (CI) = 2.6, 9.8; Tau squared (T2) = 0.1105), and was higher in S. Typhi than in S. Typhimurium (odds ratio (OR) = 3.3, 95%CI = 2, 5.7). The proportions of each of gyrB and parC mutants, and strains with Plasmid Mediated Quinolone Resistance genes (qnrA, qnrB and qnrS) were low (≤ 0.3%). Overall, 23 mutant serotypes were identified, and most strains had mutations at codons encoding Ser83 and Asp87 of gyrA (82%, 95%CI = 78, 86).

CONCLUSIONS

Mutations at gyrA appear to account for ciprofloxacin non-susceptibility in most clinical Salmonella strains in Africa. The estimates could be harnessed to develop a mismatch-amplification mutation-assay for the detection of FQ-resistant strains in Africa.

Predicting late-onset sepsis by routine neonatal screening for colonisation by gram-negative bacteria in neonates at intensive care units: a protocol for a systematic review

INTRODUCTION

Hospitals conduct extensive screening procedures to assess colonisation of the body surface of neonates by gram-negative bacteria to avoid complications like late-onset sepsis. However, the benefits of these procedures are controversially discussed. Until now, no systematic review has investigated the value of routine screening for colonisation by gram-negative bacteria in neonates for late-onset sepsis prediction.

METHODS AND ANALYSIS

We will conduct a systematic review, considering studies of any design that include infants up to an age of 12 months. We will search MEDLINE and EMBASE (inception to 2016), reference lists and grey literature. Screening of titles, abstracts and full texts will be conducted by two independent reviewers. We will extract data on study characteristics and study results. Risk of bias will be assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) and Quality in Prognosis Studies (QUIPS) tools. Subgroup analyses are planned according to characteristics of studies, participants, index tests and outcome. For quantitative data synthesis on prognostic accuracy, sensitivity and specificity of screening to detect late-onset sepsis will be calculated. If sufficient data are available, we will calculate summary estimates using hierarchical summary receiver operating characteristics and bivariate models. Applying a risk factor approach, pooled summary estimates will be calculated as relative risk or OR, using fixed-effects and random-effects models. I-squared will be used to assess heterogeneity. All calculations will be performed in Stata V14.1 (College Station, Texas, USA). The results will be used to calculate positive and negative predictive value and number needed to be screened to prevent one case of sepsis. Grading of Recommendations Assessment, Development and Evaluation (GRADE) will be used to assess certainty in the evidence. The protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guideline.

ETHICS AND DISSEMINATION

This study will not require ethical approval since it is not carried out in humans. The systematic review will be published in an open-access peer-reviewed journal.

TRIAL REGISTRATION NUMBER

CRD42016036664.

Where Sepsis and Antimicrobial Resistance Countermeasures Converge

The United Nations General Assembly debate on antimicrobial resistance (AMR) recognizes the global significance of AMR. Much work needs to be done on technology capability and capacity to convert the strategic intent of the debate into operational plans and tangible outcomes. Enhancement of the biomedical science–clinician interface requires better exploitation of systems biology tools for in-laboratory and point of care methods that detect sepsis and characterize AMR. These need to link sepsis and AMR data with responsive, real-time surveillance. We propose an AMR sepsis register, similar in concept to a cancer registry, to aid coordination of AMR countermeasures.

Multiple and mixed methods in formative evaluation: Is more better? Reflections from a South African study

Background

Formative programme evaluations assess intervention implementation processes, and are seen widely as a way of unlocking the ‘black box’ of any programme in order to explore and understand why a programme functions as it does. However, few critical assessments of the methods used in such evaluations are available, and there are especially few that reflect on how well the evaluation achieved its objectives. This paper describes a formative evaluation of a community-based lay health worker programme for TB and HIV/AIDS clients across three low-income communities in South Africa. It assesses each of the methods used in relation to the evaluation objectives, and offers suggestions on ways of optimising the use of multiple, mixed-methods within formative evaluations of complex health system interventions.

Methods

The evaluation’s qualitative methods comprised interviews, focus groups, observations and diary keeping. Quantitative methods included a time-and-motion study of the lay health workers’ scope of practice and a client survey. The authors conceptualised and conducted the evaluation, and through iterative discussions, assessed the methods used and their results.

Results

Overall, the evaluation highlighted programme issues and insights beyond the reach of traditional single methods evaluations. The strengths of the multiple, mixed-methods in this evaluation included a detailed description and nuanced understanding of the programme and its implementation, and triangulation of the perspectives and experiences of clients, lay health workers, and programme managers. However, the use of multiple methods needs to be carefully planned and implemented as this approach can overstretch the logistic and analytic resources of an evaluation.

Conclusions

For complex interventions, formative evaluation designs including multiple qualitative and quantitative methods hold distinct advantages over single method evaluations. However, their value is not in the number of methods used, but in how each method matches the evaluation questions and the scientific integrity with which the methods are selected and implemented.

Using GRADE to respond to health questions with different levels of urgency

Increasing interest exists in applying the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to environmental health evidence. While ideally applied to evidence synthesized in systematic reviews and corresponding summary tables, such as evidence profiles, GRADE's correct application requires that "the evidence that was assessed and the methods that were used to identify and appraise that evidence should be clearly described." In this article, we suggest that GRADE could be applied to evidence assembled from narrative reviews, modelled (indirect) evidence, or evidence assembled as part of a rapid response, if the underlying judgments about the certainty in this evidence are based on the relevant GRADE domains and provided transparently. Health questions that require assessing the certainty in a body of evidence to provide trustworthy answers may range from hours, to days or weeks, to a few months to scenarios that allow assessing evidence without short-term time pressures. Time frames of emergent, urgent or rapid evidence assessments will often require relying on existing summaries or rapidly compiling the available evidence and making assessments. Even without available full systematic reviews, expressing the certainty in the evidence can provide useful guidance for users of the evidence and those who evaluate certainty in effects. The ratings also help clarifying disagreement between organizations tackling similar questions about the evidence. Using the structured GRADE domains, narrative or other summaries of the evidence can be presented transparently.

Community-onset sepsis and its public health burden: a systematic review

BACKGROUND

Sepsis is a life-threatening condition and major contributor to public health and economic burden in the industrialised world. The difficulties in accurate diagnosis lead to great variability in estimates of sepsis incidence. There has been even greater uncertainty regarding the incidence of and risk factors for community-onset sepsis (COS). We systematically reviewed the recent evidence on the incidence and risk factors of COS in high income countries (North America, Australasia, and North/Western Europe).

METHODS

Cohort and case-control studies were eligible for inclusion. Medline and Embase databases were searched from 2002 onwards. References of relevant publications were hand-searched. Two reviewers screened titles/abstracts and full-texts independently. One reviewer extracted data and appraised studies which were cross-checked by independent reviewers. Disagreements were resolved via consensus. Odds ratios (ORs) and 95 percent confidence intervals (95 % CIs) were ascertained by type of sepsis (non-severe, severe, and septic shock).

RESULTS

Ten cohort and 4 case-control studies were included. There was a wide variation in the incidence (# cases per 100,000 per year) of non-severe sepsis (range: 64-514), severe sepsis (range: 40-455), and septic shock (range: 9-31). Heterogeneity precluded statistical pooling. Two cohort and 4 case-control studies reported risk factors for sepsis. In one case-control and one cohort study, older age and diabetes were associated with increased risk of sepsis. The same case-control study showed an excess risk for sepsis in participants with clinical conditions (e.g., immunosuppression, lung disease, and peripheral artery disease). In one cohort study, higher risk of sepsis was associated with being a nursing home resident (OR = 2.60, 95 % CI: 1.20, 5.60) and in the other cohort study with being physically inactive (OR = 1.33, 95 % CI: 1.13, 1.56) and smoking tobacco (OR = 1.85, 95 % CI: 1.54, 2.22). The evidence on sex, ethnicity, statin use, and body mass index as risk factors was inconclusive.

CONCLUSIONS

The lack of a valid standard approach for defining sepsis makes it difficult to determine the true incidence of COS. Differences in case ascertainment contribute to the variation in incidence of COS. The evidence on COS is limited in terms of the number and quality of studies. This review highlights the urgent need for an accurate and standard method for identifying sepsis. Future studies need to improve the methodological shortcomings of previous research in terms of case definition, identification, and surveillance practice.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015023484.

The development and validation of a meta-tool for quality appraisal of public health evidence: Meta Quality Appraisal Tool (MetaQAT)

OBJECTIVES

Most quality appraisal tools were developed for clinical medicine and tend to be study-specific with a strong emphasis on risk of bias. In order to be more relevant to public health, an appropriate quality appraisal tool needs to be less reliant on the evidence hierarchy and consider practice applicability. Given the broad range of study designs used in public health, the objective of this study was to develop and validate a meta-tool that combines public health-focused principles of appraisal coupled with a set of design-specific companion tools.

STUDY DESIGN

Several design methods were used to develop and validate the tool including literature review, synthesis, and validation with a reference standard.

METHODS

A search of critical appraisal tools relevant to public health was conducted; core concepts were collated. The resulting framework was piloted during three feedback sessions with public health practitioners. Following subsequent revisions, the final meta-tool, the Meta Quality Appraisal Tool (MetaQAT), was then validated through a content analysis of appraisals conducted by two groups of experienced public health researchers (MetaQAT vs generic appraisal form).

RESULTS

The MetaQAT framework consists of four domains: relevancy, reliability, validity, and applicability. In addition, a companion tool was assembled from existing critical appraisal tools to provide study design-specific guidance on validity appraisal. Content analysis showed similar methodological and generalizability concerns were raised by both groups; however, the MetaQAT appraisers commented more extensively on applicability to public health practice.

CONCLUSIONS

Critical appraisal tools designed for clinical medicine have limitations for use in the context of public health. The meta-tool structure of the MetaQAT allows for rigorous appraisal, while allowing users to simultaneously appraise the multitude of study designs relevant to public health research and assess non-standard domains, such as applicability.

Community-onset sepsis and its public health burden: protocol of a systematic review

BACKGROUND

Sepsis is a life-threatening condition and major contributor of public health and economic burden in the industrialised world. The heterogeneity, absence of more specific definition, and difficulties in accurate diagnosis lead to great variability in the estimates of sepsis incidence. There has been uncertainty regarding the incidence and risk factors attributable to community-onset as opposed to hospital-acquired sepsis. Community-onset sepsis has distinct host characteristics, risk factors, pathogens, and prognosis. A systematic assessment of recent evidence is warranted in light of secular changes in epidemiology, pathogens, and the uncertainties around the incidence and risk factors of community-onset sepsis. This protocol describes a systematic review which aims to synthesise the recent empirical evidence on the incidence and risk factors of community-onset sepsis, severe sepsis, and septic shock in high-income countries.

METHODS/DESIGN

English-language publications of cohort and case-control studies reporting incidence and risk factors of community-onset sepsis will be eligible for inclusion. MEDLINE and Embase databases will be searched from 2002 and onwards. References of relevant publications will be hand-searched. Two reviewers will independently screen titles/abstracts and full texts as well as extract data and appraise the risk of bias of included studies. The data extractions and risk of bias assessments will be cross-checked. Any disagreements will be resolved via consensus. The data on incidence and risk factors of sepsis will be organised and synthesised in text, tables, and forest plots. The evidence will be pooled given sufficient data and degree of similarity across study populations, exposures, and outcomes. The heterogeneity will be assessed through visual inspection of forest plots, Chi-square-based p value, and I (2) statistic. The sources of heterogeneity will be explored via subgroup analysis.

DISCUSSION

Timeliness and accuracy of diagnosis of sepsis are both crucial aspects for improving the patient's outcome. The findings of this review will be discussed with a view to better inform future recommendations on improving public-facing campaigns, timely presentation, and diagnosis of sepsis in the community. The review will also discuss gaps in evidence and highlight future research and policy-making avenues for improving public health planning.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015023484.

Towards a framework for evaluating and grading evidence in public health

The Project on a Framework for Rating Evidence in Public Health (PRECEPT) is an international collaboration of public health institutes and universities which has been funded by the European Centre for Disease Prevention and Control (ECDC) since 2012. Main objective is to define a framework for evaluating and grading evidence in the field of public health, with particular focus on infectious disease prevention and control. As part of the peer review process, an international expert meeting was held on 13-14 June 2013 in Berlin. Participants were members of the PRECEPT team and selected experts from national public health institutes, World Health Organization (WHO), and academic institutions. The aim of the meeting was to discuss the draft framework and its application to two examples from infectious disease prevention and control. This article introduces the draft PRECEPT framework and reports on the meeting, its structure, most relevant discussions and major conclusions.

[Measurement and assessment of study quality and reporting quality]

Clinical trials are undertaken to evaluate the effectiveness and safety of clinical interventions or to investigate other unclarified (e.g. diagnostic) research questions. But not every clinical study is optimally planned, conducted and analysed and is therefore exposed to risk of systematic errors which can distort (bias) the study results. Clinical studies should be conducted in accordance with specific quality criteria in order to reduce these risks. To estimate the methodological quality of studies instruments such as the Cochrane Risk of Bias tool were developed. But it can only be appraised what is reported. Often important information on the conduct and analysis of a study is missing in research articles, and in most cases detailed study protocols are not freely available. Reporting guidelines available for different study types can help improve the transparency and completeness of reports of clinical studies and thus the reporting quality.

Some notes on critical appraisal of prevalence studies: Comment on: "The development of a critical appraisal tool for use in systematic reviews addressing questions of prevalence"

Decisions in healthcare should be based on information obtained according to the principles of Evidence-Based Medicine (EBM). An increasing number of systematic reviews are published which summarize the results of prevalence studies. Interpretation of the results of these reviews should be accompanied by an appraisal of the methodological quality of the included data and studies. The critical appraisal tool for prevalence studies developed and tested by Munn et al. comprises 10 items and aims at targeting all kinds of prevalence studies. This comment discusses the pros and cons of different designs of quality appraisal tools and highlights their importance for systematic reviews of prevalence studies. Beyond piloting, which has been performed in the study by Munn et al., it is suggested here that the validity of the tool should be tested, including reproducibility and inter-rater reliability. It is concluded that studies as the one by Munn et al. will help to establish a critical understanding of methodological quality and will support the use of systematic reviews of non-intervention studies for health policy making.