Wednesday, September 30, 2020

Four Questions to Ask Before Replicating a Systematic Review

Just as with individual research trials, the replication of a systematic review can shed new light on an existing topic or help further solidify our assessment of the certainty of a body of evidence. However, duplication of efforts that is done unintentionally or without deliberate consideration of methodology (e.g., how similar or different the new review will be in terms of evidence searching, inclusion, and synthesis) is wasteful. How is one to know when the replication of a systematic review is appropriate and warranted?

A new consensus checklist recently published by Tugwell and colleagues in BMJ provides guidance on when - and when not - to conduct a systematic review replication. Driven by a six-person executive team, the checklist was informed by the input of methodologists, including experts in fields ranging from clinical epidemiology to guideline development and health economics, to knowledge users - those involved in the funding, commissioning, and development of systematic reviews. Two patients were involved in the development team and an additional 17 patient and public representatives were consulted for input via survey. 

The process culminated in the drafting of the checklist in a face-to-face setting, with an original 12 proposed items solidified into a final four. The items ask whether replication of the systematic review is of high priority (e.g., whether replication results will be expected to guide policymakers or be of relevance to stakeholders), whether there are certain methodological concerns (such as search design, scope of PICOs, etc.) that will be clarified or improved with a replication; whether the implementation of the replication's findings would be expected to have a sizable positive or negative impact on the population or individual level; and whether resources (e.g., time, money) spent on replication would not be better spent on conducting a new review to answer a novel question. 

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The ultimate decision of whether or not to replicate should be informed by the answers to these questions, the authors note, and left up to contextualized judgment rather than a quantitative threshold. Further, some of the items may be of higher or lower relevancy depending on the stakeholders for a specific review topic, and "middle-ground" solutions, such as repeating only the parts of a systematic review in need of replication, should be considered individually. The authors plan to test the usability, acceptability, and usefulness of this newly proposed tool with relevant end-users.

Tugwell, P., Welch, V.A., Karunananthan, S., Maxwell, L.J., Akl, E.A., Avey, M.T., ... & White, H. 2020. When to replicate systematic reviews of interventions: Consensus checklist. BMJ 370:m2864. 

Manuscript available from the publisher's website here. 

Thursday, September 24, 2020

Pre-Print of PRISMA 2020 Updated Reporting Guidelines Released

Upon their publication in 2009, the PRISMA guidelines have become the standard for reporting in systematic reviews and meta-analyses. Now, 11 years later, the PRISMA checklist has received a fresh facelift for 2020 that incorporates the methodological advances that have taken place over the intervening years.

In a recently released pre-print, Page and colleagues describe their approach to designing the new and improved PRISMA. Sixty reporting documents were reviewed to identify any new items deserving of consideration and 110 systematic review methodologists and journal editors were surveyed for feedback. The new PRISMA 2020 draft was then developed based on discussion at an in-person meeting and iteratively revised based on co-author input and a sample of 15 experts.

The result is an expanded, 27-item checklist replete with elaboration of the purpose for each item, a sub-checklist specifically for reporting within the abstract, and revised flow diagram templates for both original and updated systematic reviews. Here are some of the major changes and additions to be aware of:

  • Recommendation to present search strategies for all databases instead of just one.
  • Recommendation that authors list "near-misses," or studies that met many but not all inclusion criteria, in the results section.
  • Recommendation to assess certainty of synthesized evidence.
  • New item for declaration of Conflicts of Interest.
  • New item to indicate whether data, analytic code, or other materials have been made publicly available.
Page, M., McKenzie, J., Bossuyt, P., Boutron, I., Hoffman, T., Mulow, C., ... & Moher, D. 2020. The PRISMA 2020 Statement: An updated guideline for reporting systematic reviews. 

Pre-print available from MetaArXiv here. 

Friday, September 18, 2020

WHO Guidelines are Considering Health Equity More Frequently, but Reporting of Judgments is Often Incomplete

The GRADE evidence-to-decision (EtD) framework was developed as a way to more explicitly and transparently inform the considerations of the implications of clinical recommendations, such as the potential positive or negative impacts on health equity. A new analysis of World Health Organization (WHO) guidelines published between 2014 and 2019 - over half (54%) of which used the EtD framework - examines the consideration of health equities in the guidelines' resulting recommendations.

Dewidar and colleagues found that the guidelines utilizing the EtD framework were more likely to be addressing health issues in socially disadvantaged populations (42% of those developed with the EtD versus 24% of those without). What's more, the use of the EtD framework has risen over time, from 10% of guidelines published in 2016 (the year of the EtD's introduction) to 100% of those published within the first four months of 2019. Use of the term "health equity" increased to a similar degree over this period.

Just over one-third (38%) of recommendations were judged to increase or probably increase health equity, while 15% selected the judgment "Don't know/uncertain" and 8% provided no judgment. Just over one-quarter (28%) of the recommendations utilizing the EtD framework provided evidence for the judgment. When detailed judgments were provided, they were more likely to discuss the potential impacts of place of residence and socioeconomic status and less likely to explicitly consider gender, education, race, social capital, occupation, or religion.

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The authors conclude that while consideration of the potential impacts of recommendations on health equity has increased considerably in recent years, reporting of these judgments is still often incomplete. Reporting which published research evidence or additional considerations were used to make a judgment, as well as considering the various PROGRESS factors (Place, Race, Occupation, Gender, Religion, Education, Socioeconomic status, and Social capital) will likely improve the transparency of recommendations in future guidelines where health equity impacts are of concern.

Dwidr, O., Tsang, P., León-Garcia, M., Mathew, C., Antequera, A., Baldeh, T., ... & Welch, V. 2020. Over half of WHO guidelines published from 2014 to 2019 explicitly considered health equity issues: A cross-sectional suvey. J Clin Epidemiol 127:125-133.

Manuscript available from the publisher's website here.

Monday, September 14, 2020

Timing and Nature of Financial Conflicts of Interest Often Go Unreported, Systematic Survey Finds

The proper disclosure and management of financial Conflicts of Interest (FCOI) within the context of a published randomized controlled trial is vital to alerting the reader to the sources of funding for the research and other financial factors that may influence the design, conduct, or reporting of the trial.

A recently published cross-sectional survey by Hakoum and colleagues examined the nature of FCOI reporting in a sample of 108 published trials found that 99% of these reported individual author disclosures, while only 6% reported potential sources of FCOI at the institutional level. Individual authors reported a median of 2 FCOIs. Among the 2,972 FCOIs reported by 806 individuals, the greatest proportion came from personal fees other than employment income (50%) and from grants (34%). Further, of those disclosing individual FCOI, a large majority (85%) were provided by private-for-profit entities. Notably, only one-third (33%) of these disclosures included the timing of the funding in relation to the trial, 17% reported the relationship between the funding source and the trial, and just 1% reported the monetary value.

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Using a multivariate regression, the authors found that the reporting of FCOI by individual authors was positively associated with nine factors, most strongly with the authors being from an academic institution (OR: 2.981; 95% CI: 2.415 – 3.680), with the funding coming from an entity other than private-for-profit (OR: 2.809; 95% CI: 2.274 – 3.470), and the first author’s affiliation being from a low- or middle-income country (OR: 2.215; 95% CI: 1.512 – 3.246).


More explicit and complete reporting of FCOIs, the authors conclude, may improve readers’ level of trust in the results of a published trial and in the authors presenting them. To improve the nature and transparency of FCOI reporting, researchers may consider disclosing details related to the funding’s source, including the timing of the funding in relation to the conduct and publication of the trial, the relationship between the funding source and the trial, and the monetary value of the support.

Hakoum, M.B., Noureldine, H., Habib, J.R., Abou-Jaoude, E.A., Raslan, R., Jouni, H., ... & Akl, E.A. (2020). Authors of clinical trials seldom reported details when declaring their individual and institutional financial conflicts of interest: A cross-sectional survey. J Clin Epidemiol 127:49-58.

Manuscript available from the publisher's website here

Tuesday, September 8, 2020

Assessing Health-Related Quality of Life Improvement in the Modern Anticancer Therapy Era

Recent breakthroughs in anticancer therapies such as small-molecule drugs and immunotherapies have made improvements in Health-Related Quality of Life (HRQOL) possible among cancer patients over the course of treatment. In a recent paper published in the Journal of Clinical Epidemiology, Cottone and colleagues are the first to propose the framework for assessing the change in HRQOL over time in these patients: Time to HRQOL Improvement (TTI), and Time to Sustained HRQOL Improvement (TTSI).

In the proposed framework, TTI is based on the time to the “first clinically meaningful improvement occurring in a given scale or in at least one among different scales” – for instance, a minimal important difference (MID) of 5 points on the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire – Core 30 (QLQ-C30). The authors suggest utilizing the first posttreatment score as the baseline measurement for monitoring improvements over time. “Sustained improvement” was defined as the first improvement that is not followed by a deterioration that meets or exceeds the MID.


The use of Kaplan-Meier curves and Cox proportional hazards is inappropriate for these outcomes, the authors argue, as it does not allow for possible competing events, such as disease progression, toxicity, or the possibility of an earlier improvement in another scale when multiple scales are used. They propose the use of the Fine-Gray model for the evaluation of TTI and TTSI and pilot it with a case study of 124 newly diagnosed chronic myeloid leukemia patients undergoing first-line treatment with nilotinib.

Time To Improvement (TTI) and Time to Sustained Improvement (TTSI) can be used to elucidate differences in HRQOL responses to treatment based on baseline characteristics. Here, the figure shows TTSI in fatigue scores based on hemoglobin level at baseline. Click to enlarge.

Using this model, the authors found that improvements in fatigue scores appeared more quickly than those in physical functioning when measuring scores from baseline (pre-treatment), but upon using first post-treatment score as the baseline, the differences between improvement rates in fatigue and physical functioning diminished. Additionally, a lower baseline hemoglobin level was associated with earlier sustained improvements in fatigue.


While the proposed method of evaluating TTI and TTSI has some limitations, such as lower statistical power than other ways of tracking changes in HRQOL over time, it also has notable strengths. In particular, this method can be used to elucidate differences between treatment approaches that show similar survival outcomes so that the approach with shorter TTI and TTSI can be favored.

Cottone, F., Collins, G.S., Anota, A., Sommer, K., Giesinger, J.M., Kieffer, J.M., ... & Efficace, F. (2020). Time to health-related quality of life improvement analysis was developed to enhance evaluation of modern anticancer therapies. J Clin Epidemiol 127:9-18.

Manuscript available from publisher's website here. 

Wednesday, September 2, 2020

A New Tool for Assessing the Credibility of Effect Modification Cometh: Introducing the ICEMAN

Effect modification goes by many other names: “subgroup effect,” “statistical interaction,” and “moderation,” to name a few. Regardless of what it’s called, the existence of effect modification in the context of an individual study means that the effect of an intervention varies between individuals based on an attribute such as age, sex, or severity of underlying disease. Similarly, a systematic review may aim to identify effect modification between individual studies based on their setting, year of publication, or methodological differences (often called a “subgroup analysis”).

As many as one-quarter of randomized controlled trials (RCTs) and meta-analyses examine their findings for potential evidence of effect modification, according to a paper by Schandelmaier and colleagues published in the latest edition of CMAJ. However, it is not uncommon for claims of effect modification to be later proved spurious, which may negatively affect the quality of care in those subgroups of patients. Potential sources of these claims range from simple random chance to issues with selective reporting and misguided application of statistical analyses.

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In “Development of the Instrument to assess the Credibility of Effect Modification in Analyses (ICEMAN) in randomized controlled trials and meta-analyses,” the authors present a novel tool for evaluating the presence of a potential modifier. While several sets of criteria have been developed in the past for this purpose, the ICEMAN is the first to be based on a rigorous development process and refined with formal user testing.


First, the authors conducted a systematic survey of the literature to ensure a comprehensive understanding of the previously proposed criteria for evaluating effect modification. Thirty sets were identified, none of which adequately reflected the authors’ conceptual framework. Second, an expert panel of 15 members was identified randomly from a list of 40 identified through the systematic survey. These experts then pared down the initial list of 36 candidate criteria to 20 required and eight optional items. After developing a manual for its use, the authors tested the instrument among a diverse group of 17 potential users, including authors of Cochrane reviews and RCTs and journal editors using a semi-structured interview technique.

Schandelmaier, S., Briel, M., Varadhan, R., Schmid, C.H., Devasenapathy, N., Hayward, R.A., Gagnier, J., ... & Guyatt, G.H. 2020. Development of the Instrument to assess the Credibility of Effect Modification Analyses (ICEMAN) in randomized controlled trials and meta-analyses. CMAJ 192:E901-906.

Manuscript available at the publisher's website here