Few systematic reviews exist documenting the extent of bias: a systematic review

OBJECTIVE: To summarize the evidence concerning bias and confounding in conducting systematic reviews (SRs). STUDY DESIGN AND SETTING: Literature was identified through searching the Cochrane Library, MEDLINE, PsycINFO until November 2006, and the authors' files. Studies were included if they were SRs of bias that can occur while conducting a SR. Risk of bias in the SRs was appraised using the Oxman and Guyatt index. RESULTS: Ten SRs were included. All examined biases related to searching for evidence (e.g., publication bias). One also reported bias associated with obtaining data from included studies (e.g., outcome reporting bias). To minimize bias, data suggest including unpublished material, hand searching for additional material, searching multiple databases, assessing for publication bias, and periodically updating SRs. No SRs were found examining biases related to choosing studies for inclusion or combining studies. CONCLUSIONS: There is little evidence from SRs to support commonly practiced methods for conducting SRs. No SRs summarized studies with prospective designs and most had moderate or minimal risk of bias. Future research should examine bias that can occur during the selection of studies for inclusion and the synthesis of studies, as well as systematically review the existing empirical evidence.     

Cocaine and thrombosis: a narrative systematic review of clinical and in-vivo studies

Purpose  

To systematically review the literature pertaining to the link between cocaine and either arterial or venous thrombosis.     

Tobacco smoking and multiple sclerosis: a systematic review of systematic and narrative reviews of observational studies

Aim

The aim of this review was to systematically review systematic and narrative reviews of observational studies published on the relation between tobacco smoking and multiple sclerosis (MS).

Subjects and methods

A systematic search of the literature in PubMed and Scopus was conducted in June 2016. Two authors independently reviewed the search results and extracted key points. Review studies (i.e., review, systematic, narrative, or meta-analysis) that reported on smoking and MS were selected. The methodological quality of included systematic reviews and meta-analyses was assessed using the AMSTAR checklist. The methodological quality of narrative reviews was evaluated using a seven-item measure developed by the authors.

Results

Seventeen reviews met the inclusion criteria and were categorized as either systematic reviews or narrative reviews. Smoking was associated with increased risk of MS for ever- compared with never-smokers and current compared with non-smokers. The summary odds ratio of MS for ever-smokers versus never-smokers varied between 1.40 (95% CI: 1.29–1.52) and 1.46 (95% CI: 1.33–1.59).

Conclusion

This review of reviews identifies smoking as a risk factor for MS susceptibility. However, more research is needed to conclusively establish the mechanisms driving this association.

     

Consumer evaluation of food with nutritional benefits: a systematic review and narrative synthesis

As a consequence of the growing interest in, and development of, various types of food with nutritional benefits, the modern consumer views their kitchen cabinet more and more as a medicine cabinet. Given that consumer evaluation of food is considered key to the successful production, marketing and finally consumption of food, a procedure commonly used in medical fields was employed to systematically review and summarize evidence of consumer evaluation studies on nutritious foods. The focus is primarily on consumer understanding of nutritious food and the underlying determinants of consumer evaluation. Our results highlight four groups of key determinants: (1) nutrition knowledge and information; (2) attitudes, beliefs, perceptions and behavioural determinants; (3) price, process and product characteristics; and (4) socio-demographics. The findings also point to the importance of understanding consumer acceptance as one many concepts in the consumer evaluation process, and provide support for developing appropriate strategies for improving health and well-being of consumers.     

Knowledge exchange processes in organizations and policy arenas: a narrative systematic review of the literature

Context: This article presents the main results from a large‐scale analytical systematic review on knowledge exchange interventions at the organizational and policymaking levels. The review integrated two broad traditions, one roughly focused on the use of social science research results and the other focused on policymaking and lobbying processes. Methods: Data collection was done using systematic snowball sampling. First, we used prospective snowballing to identify all documents citing any of a set of thirty‐three seminal papers. This process identified 4,102 documents, 102 of which were retained for in‐depth analysis. The bibliographies of these 102 documents were merged and used to identify retrospectively all articles cited five times or more and all books cited seven times or more. All together, 205 documents were analyzed. To develop an integrated model, the data were synthesized using an analytical approach. Findings: This article developed integrated conceptualizations of the forms of collective knowledge exchange systems, the nature of the knowledge exchanged, and the definition of collective‐level use. This literature synthesis is organized around three dimensions of context: level of polarization (politics), cost‐sharing equilibrium (economics), and institutionalized structures of communication (social structuring). Conclusions: The model developed here suggests that research is unlikely to provide context‐independent evidence for the intrinsic efficacy of knowledge exchange strategies. To design a knowledge exchange intervention to maximize knowledge use, a detailed analysis of the context could use the kind of framework developed here.     

Beyond Medline: reducing bias through extended systematic review search

OBJECTIVE: To evaluate the sensitivity and precision of various extended search methods in identifying randomized controlled trials (RCTs) for systematic reviews. METHOD: Prospective analysis of extended search methods (specialized databases or trial registries, reference lists, hand-searching, personal communication, and Internet) used in two systematic reviews of RCTs. The gold standard was the total number of RCTs identified by major databases (MEDLINE, EMBASE, etc.) and extended search strategies combined. Sensitivity was the proportion of all known RCTs identified by any extended search method. Precision reflected the proportion of all items uncovered by any extended search method that actually were RCTs. RESULTS: The extended search identified 94 additional RCTs for the systematic reviews beyond those identified with the major databases. Specialized databases and trial registries had the highest sensitivity and precision for the lipid-lowering project (13.6% and 52.7%, respectively; p < .05) followed by scanning of reference lists (7.2% sensitivity and 41.9% precision; p <.05). Hand-searching was more effective than personal communication and Internet searching (1.7% sensitivity and 12.2% precision; p < .05). The acupuncture project had slightly different results, with the specialized databases and trial registries tied with the review of reference lists for highest sensitivity (14.2%). The precision followed the same trend as the lipid-lowering project (17.6% specialized databases; 8.3% reference lists; p < .05). A post-hoc analysis showed that 75 of the 94 RCTs were indexed in the major databases but missed by the major database search. CONCLUSIONS: Extended searching identified additional RCTs for the systematic reviews beyond those found in major databases. Specialized databases and trial registries were most effective. An important number of RCTs were missed by the major database search. Timing and accuracy of indexing may explain this finding. The definitive measure, whether there is an association between the method used to uncover RCTs, the quality of the items uncovered and their impact on systematic review results, is yet to be determined.     

Role of context in evaluating neighbourhood interventions promoting positive youth development: a narrative systematic review

Objectives

This narrative systematic review explored (1) how neighbourhood interventions promote positive youth development (PYD) and (2) the role of context for these interventions. We asked: How do neighbourhood interventions become effective in promoting PYD for adolescents aged 12–18 years?

Methods

Articles (n = 19) were analyzed using a framework integrating standards of health promotion evaluation and elements of the ecological systems perspective.

Results

First, results highlight the key characteristics of interventions that promote PYD. An intervention’s atmosphere encouraging supportive relationships and an intervention’s activities aiming to build skills and that are real and challenging promoted PYD elements including cognitive competences, confidence, connection, leadership, civic engagement, and feelings of empowerment. Secondly, this review identified facilitators (e.g. partnerships and understanding of the community) and constraints (e.g. funding and conflicts) to an intervention’s integration within its context.

Conclusions

Results regarding interventions’ characteristics promoting PYD confirm findings from past reviews. Our findings indicate that context is an important element of effective interventions. This review encourages future evaluations to analyze the role of context to build a better understanding of its role.     

Time and chronic illness: a narrative review

Purpose

This narrative review is concerned with the ways in which the relationships between time and chronic illnesses have been chartered in recent literature. It aims to identify types of time (referred to here as temporal structures) most commonly reported in chronic illness literature and to assess their bearing on people’s lived experiences.

Methods

Literature searches of three electronic databases (Google Scholar, MEDLINE, and PubMed) were carried out in November 2014 of articles published between 1970 and 2013 using the following search terms (and derivatives): chronic illness AND time AND (patient OR carer). The review followed four procedural steps: (a) comprehensive search, (b) temporal structure appraisal, (c) synthesis of findings, and (d) critical appraisal.

Results

Forty studies met the inclusion criteria and were included for review. Four types of called temporal structures had a strong presence in the literature: calendar and clocked time, biographical time, past–present–future time, and inner time and rhythms. The first three temporal structures are largely understood socially, and the fourth is predominantly understood in and through the body. Several studies reported more than one temporal structure as informing people’s chronic illness experiences. A wide array of chronic illnesses were represented in these studies. Few studies reported on the experiences of people with multi-morbid chronic illnesses.

Conclusion

Chronic illness induces new relationships to time. Drawing on Hyden (Sociol Health Illn 19(1):48–69, 1997), it is suggested that “narrative” storytelling—as a temporally informed analytic device—might prove effective for reconciling the tensions emergent from new and multiple relationships to time that chronic and multiple illnesses create. Opportunities exist for healthcare practitioners and health services to offer patients illness support that is cognisant of their relationships to time.

     

Effectiveness of safety training interventions for supervisors: A systematic review and narrative synthesis

A wealth of research demonstrates that work unit supervisors serve a critical function in protecting the safety and health of workers. A systematic review examined the effectiveness of workplace safety training interventions intended for various supervisor populations published from 2000 to 2019. A search of seven electronic databases was supplemented with hand searches from the reference lists of identified publications, relevant scientific journals, and the gray literature. This review included an assessment of the methodological quality using a modified version of the Quality Assessment Tool for Quantitative Studies. A total of 22 peer-reviewed studies met a set of inclusion criteria and were subsequently assessed for methodological quality. Training interventions were grouped into five topical domains: ergonomics, leadership, supervisor-worker interaction, injury, and disability management, and general safety education. Consistent evidence was found for the effectiveness of supervisory training interventions across several outcome measures. To our knowledge, this is the first study to synthesize the literature on supervisory training interventions in the area of occupational safety. While the results are encouraging, they must be viewed with caution due to the fact that the methodological rigor of the reviewed studies was low.     

Implementing and delivering personalised budgets for drug and alcohol users: A narrative systematic review

Personalised budgets have historically been provided to groups of people with varying long‐term health and social care needs. Since 2010, there has been increasing interest in providing personal budgets (PBs) to individuals with a history of drug and alcohol use in the UK, reflecting the policy and practice shift towards whole person recovery from substance use. However, information on implementing, delivering, and receiving such initiatives with this group is limited. This systematic review was conducted to identify and collate the existing experiences of providing personalised budgets to drug and alcohol users. Between March and April 2017, we searched six electronic and 11 grey literature databases for English language studies published between 1990 and April 2017 which described the implementation and delivery of personalised budget initiatives with drug and alcohol users. Search results (n = 6,749) were screened against inclusion and exclusion criteria; six records met the inclusion criteria. Across the studies, staff reported specific moral, ethical, and practical issues which affected the implementation and delivery of personalised budgets to drug and alcohol users. Staff working with drug and alcohol users with PBs reported greater job satisfaction due to having greater flexibility and autonomy but they had increased workloads and additional responsibilities beyond their remit and training. Drug and alcohol users’ experiences of receiving personalised budgets included varying levels of awareness, knowledge, and control of their budgets, and difficulties in understanding what the budgets could be used for. Nevertheless, personalised budgets had been used to purchase various services and items beyond traditional drug and alcohol treatment. Outcomes for drug and alcohol users included reduced drug use, improved relationships, improved mental and physical well‐being, and better daily structure. Although the review suggests that providing personalised budgets to drug and alcohol users presents unique implementation and delivery challenges, these were not insurmountable.     

Gender bias in shared decision-making among cancer care guidelines: A systematic review

Background

In cancer care, the promotion and implementation of shared decision-making in clinical practice guidelines (CPG) and consensus statements may have potential differences by gender.

Objective

To systematically analyse recommendations concerning shared decision-making in CPGs and consensus statements for the most frequent cancers exclusively among males (prostate) and females (endometrial).

Search Strategy

We prospectively registered the protocol at PROSPERO (ID: RD42021241127). MEDLINE, EMBASE, Web of Science, Scopus and online sources (8 guideline databases and 65 professional society websites) were searched independently by two reviewers, without language restrictions.

Inclusion Criteria

CPGs and consensus statements about the diagnosis or treatment of prostate and endometrial cancers were included from January 2015 to August 2021.

Data Extraction and Synthesis

Quality assessment deployed a previously developed 31-item tool and differences between the two cancers analysed.

Main Results

A total of 176 documents met inclusion criteria, 97 for prostate cancer (84 CPGs and 13 consensus statements) and 79 for endometrial cancer (67 CPGs and 12 consensus statements). Shared decision-making was recommended more often in prostate cancer guidelines compared to endometrial cancer (46/97 vs. 13/79, 47.4% vs. 16.5%; p < .001). Compared to prostate cancer guidelines (mean 2.14 items, standard deviation 3.45), compliance with the shared-decision-making 31-item tool was lower for endometrial cancer guidelines (mean 0.48 items, standard deviation 1.29) (p < .001). Regarding advice on the implementation of shared decision-making, it was only reported in 3 (3.8%) endometrial cancer guidelines and in 16 (16.5%) prostate cancer guidelines (p < .001).

Discussion and Conclusions

We observed a significant gender bias as shared decision-making was systematically more often recommended in the prostate compared to endometrial cancer guidelines. These findings should encourage new CPGs and consensus statements to consider shared decision-making for improving cancer care regardless of the gender affected.

Patient or Public Contribution

The findings may inform future recommendations for professional associations and governments to update and develop high-quality clinical guidelines to consider patients' preferences and shared decision-making in cancer care.