Comparison of seven popular structured dietary programmes and risk of mortality and major cardiovascular events in patients at increased cardiovascular risk: systematic review and network meta-analysis.

OBJECTIVE: To determine the relative efficacy of structured named diet and health behaviour programmes (dietary programmes) for prevention of mortality and major cardiovascular events in patients at increased risk of cardiovascular disease. DESIGN: Systematic review and network meta-analysis of randomised controlled trials. DATA SOURCES: AMED (Allied and Complementary Medicine Database), CENTRAL (Cochrane Central Register of Controlled Trials), Embase, Medline, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and ClinicalTrials.gov were searched up to September 2021. STUDY SELECTION: Randomised trials of patients at increased risk of cardiovascular disease that compared dietary programmes with minimal intervention (eg, healthy diet brochure) or alternative programmes with at least nine months of follow-up and reporting on mortality or major cardiovascular events (such as stroke or non-fatal myocardial infarction). In addition to dietary intervention, dietary programmes could also include exercise, behavioural support, and other secondary interventions such as drug treatment. OUTCOMES AND MEASURES: All cause mortality, cardiovascular mortality, and individual cardiovascular events (stroke, non-fatal myocardial infarction, and unplanned cardiovascular interventions). REVIEW METHODS: Pairs of reviewers independently extracted data and assessed risk of bias. A random effects network meta-analysis was performed using a frequentist approach and grading of recommendations assessment, development and evaluation (GRADE) methods to determine the certainty of evidence for each outcome. RESULTS: 40 eligible trials were identified with 35 548 participants across seven named dietary programmes (low fat, 18 studies; Mediterranean, 12; very low fat, 6; modified fat, 4; combined low fat and low sodium, 3; Ornish, 3; Pritikin, 1). At last reported follow-up, based on moderate certainty evidence, Mediterranean dietary programmes proved superior to minimal intervention for the prevention of all cause mortality (odds ratio 0.72, 95% confidence interval 0.56 to 0.92; patients at intermediate risk: risk difference 17 fewer per 1000 followed over five years), cardiovascular mortality (0.55, 0.39 to 0.78; 13 fewer per 1000), stroke (0.65, 0.46 to 0.93; 7 fewer per 1000), and non-fatal myocardial infarction (0.48, 0.36 to 0.65; 17 fewer per 1000). Based on moderate certainty evidence, low fat programmes proved superior to minimal intervention for prevention of all cause mortality (0.84, 0.74 to 0.95; 9 fewer per 1000) and non-fatal myocardial infarction (0.77, 0.61 to 0.96; 7 fewer per 1000). The absolute effects for both dietary programmes were more pronounced for patients at high risk. There were no convincing differences between Mediterranean and low fat programmes for mortality or non-fatal myocardial infarction. The five remaining dietary programmes generally had little or no benefit compared with minimal intervention typically based on low to moderate certainty evidence. CONCLUSIONS: Moderate certainty evidence shows that programmes promoting Mediterranean and low fat diets, with or without physical activity or other interventions, reduce all cause mortality and non-fatal myocardial infarction in patients with increased cardiovascular risk. Mediterranean programmes are also likely to reduce stroke risk. Generally, other named dietary programmes were not superior to minimal intervention. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016047939.

Evaluation of hospital staff's perceived quality of librarian-mediated literature searching services.

OBJECTIVE: The research evaluated the perceived quality of librarian-mediated literature searching services at one of Canada's largest acute care teaching hospitals for the purpose of continuous quality improvement and investigation of relationships between variables that can impact user satisfaction. METHODS: An online survey was constructed using evidence-based methodologies. A systematic sample of staff and physicians requesting literature searches at London Health Sciences Centre were invited to participate in the study over a one-year period. Data analyses included descriptive statistics of closed-ended questions and coding of open-ended questions. RESULTS: A range of staff including clinicians, researchers, educators, leaders, and analysts submitted a total of 137 surveys, representing a response rate of 71%. Staff requested literature searches for the following "primary" purposes: research or publication (34%), teaching or training (20%), informing a policy or standard practice (16%), patient care (15%), and "other" purposes (15%). While the majority of staff (76%) submitted search requests using methods of written communication, including email and search request forms, staff using methods of verbal communication, including face-to-face and telephone conversations, were significantly more likely to be extremely satisfied with the librarian's interpretation of the search request (p=0.004) and to rate the perceived quality of the search results as excellent (p=0.005). In most cases, librarians followed up with staff to clarify the details of their search requests (72%), and these staff were significantly more likely to be extremely satisfied with the librarian's interpretation of the search request (p=0.002). CONCLUSIONS: Our results demonstrate the limitations of written communication in the context of librarian-mediated literature searching and suggest a multifaceted approach to quality improvement efforts.