Dietary risk factors for hip fracture in adults: An umbrella review of meta-analyses of prospective cohort studies

AIM

To summarise the totality of evidence regarding dietary risk factors for hip fracture in adults, evaluating the quality of evidence, to provide recommendations for practice and further research.

DESIGN

Systematic review of meta-analyses of prospective cohort studies.

ELIGIBILITY CRITERIA

Systematic reviews with meta-analyses reporting summary risk estimates for associations between hip fracture incidence and dietary exposures including oral intake of a food, food group, beverage, or nutrient, or adherence to dietary patterns.

INFORMATION SOURCES

Medline, Embase, Web of Science, and the Cochrane Library from inception until November 2020.

DATA SYNTHESIS

The methodological quality of systematic reviews and meta-analyses was assessed using AMSTAR-2, and the quality of evidence for each association was assessed using GRADE. Results were synthesised descriptively.

RESULTS

Sixteen systematic reviews were identified, covering thirty-four exposures, including dietary patterns (n = 2 meta-analyses), foods, food groups, or beverages (n = 16), macronutrients (n = 3), and micronutrients (n = 13). Identified meta-analyses included 6,282 to 3,730,424 participants with between 322 and 26,168 hip fractures. The methodological quality (AMSTAR-2) of all systematic reviews was low or critically low. The quality of evidence (GRADE) was low for an inverse association between hip fracture incidence and intake of fruits and vegetables combined (adjusted summary relative risk for higher vs lower intakes: 0.92 [95% confidence interval: 0.87 to 0.98]), and very low for the remaining thirty-three exposures.

CONCLUSION

Dietary factors may play a role in the primary prevention of hip fracture, but the methodological quality of systematic reviews and meta-analyses was below international standards, and there was a lack of high-quality evidence. More long-term cohort studies reporting absolute risks and robust, well-conducted meta-analyses with dose-response information are needed before policy guidelines can be formed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020226190.

The Suitability of End Point Designs for Health Technology Assessment in Chronic Pain Studies

OBJECTIVES

To identify the pain instruments and study end points most commonly used in clinical trial settings and to provide insight into the extent to which outcome measures in clinical studies are meeting payer needs.

METHODS

A literature review was conducted to identify published clinical studies and ongoing/recently completed registered trials in chronic pain. Inclusion criteria were interventional study, chronic pain in adults, and pain measured within the primary end point.

RESULTS

Of 1256 PubMed citations and 3006 clinical trial registry entries, 356 reported large clinical studies in pain populations (e.g., malignant, neuropathic, functional, and musculoskeletal). Studies were designed for superiority in 28% of PubMed citations and 8% of registry entries. The primary end points of most studies were single-dimension pain instruments, such as the numerical rating scale (n = 131) and the visual analogue scale (n = 69). In cases in which multidimensional pain end points were used, this was most commonly the Brief Pain Inventory (n = 37). Payer-relevant end points were typically limited to secondary end points, and were limited and/or reported inconsistently in published studies and ongoing/recently completed studies: preference-weighted quality of life (36% and 42%), resource use (2% and 8%), physical function (28% and 39%), and psychological function (25% and 24%).

CONCLUSIONS

Most pain trials were not designed to show superiority to an active comparator, and they used single-dimension pain scales as their primary end point in combination with a broader selection of secondary end points. The inclusion of payer-relevant end points among clinical trials was inconsistent.

Burden of paediatric influenza in Western Europe: a systematic review

Background

Influenza illness in children causes significant clinical and economic burden. Although some European countries have adopted influenza immunisation policies for healthy children, the debate about paediatric influenza vaccination in most countries of the European Union is ongoing. Our aim was to summarise influenza burden (in terms of health outcomes and economic burden) in children in Western Europe via a systematic literature review.

Methods

We conducted a systematic literature search of PubMed, EMBASE, and the Cochrane Library (1970-April 2011) and extracted data on influenza burden in children (defined as aged ≤ 18 years) from 50 publications (13 reporting laboratory-confirmed influenza; 37 reporting influenza-like illness).

Results

Children with laboratory-confirmed influenza experienced hospitalisations (0.3%-20%), medical visits (1.7-2.8 visits per case), antibiotic prescriptions (7%-55%), and antipyretic or other medications for symptomatic relief (76%-99%); young children and those with severe illness had the highest rates of health care use. Influenza in children also led to absenteeism from day care, school, or work for the children, their siblings, and their parents. Average (mean or median) length of absence from school or day care associated with confirmed influenza ranged from 2.8 to 12.0 days for the children, from 1.3 to 6.0 days for their siblings, and from 1.3 to 6.3 days for their parents. Influenza negatively affected health-related quality of life in children with asthma, including symptoms and activities; this negative effect was smaller in vaccinated children than in non-vaccinated children.

Conclusions

Influenza burden in children is substantial and has a significant direct impact on the ill children and an indirect impact on their siblings and parents. The identified evidence regarding the burden of influenza may help inform both influenza antiviral use in children and paediatric immunisation policies in European countries.

Epidemiology of chronic obstructive pulmonary disease: a literature review

The aim of this study is to quantify the burden of chronic obstructive pulmonary disease (COPD) – incidence, prevalence, and mortality – and identify trends in Australia, Canada, France, Germany, Italy, Japan, The Netherlands, Spain, Sweden, the United Kingdom, and the United States of America. A structured literature search was performed (January 2000 to September 2010) of PubMed and EMBASE, identifying English-language articles reporting COPD prevalence, incidence, or mortality. Of 2838 articles identified, 299 full-text articles were reviewed, and data were extracted from 133 publications. Prevalence data were extracted from 80 articles, incidence data from 15 articles, and mortality data from 58 articles. Prevalence ranged from 0.2%–37%, but varied widely across countries and populations, and by COPD diagnosis and classification methods. Prevalence and incidence were greatest in men and those aged 75 years and older. Mortality ranged from 3–111 deaths per 100,000 population. Mortality increased in the last 30–40 years; more recently, mortality decreased in men in several countries, while increasing or stabilizing in women. Although COPD mortality increased over time, rates declined more recently, likely indicating improvements in COPD management. In many countries, COPD mortality has increased in women but decreased in men. This may be explained by differences in smoking patterns and a greater vulnerability in women to the adverse effects of smoking.

Annualized relapse rate of first-line treatments for multiple sclerosis: a meta-analysis, including indirect comparisons versus fingolimod

OBJECTIVES

Previous systematic reviews and meta-analyses of treatments in relapsing-remitting multiple sclerosis (RRMS) derived their findings from either placebo-controlled studies only or separately from head-to-head and comparative studies. The purpose of this study is to compare annualized relapse rates (ARR) of fingolimod versus all of the commonly used first-line treatments in RRMS using evidence from both placebo-controlled and head-to-head studies. In absence of the head-to-head data between fingolimod and the other treatments, these comparisons were formed using meta-analysis techniques for indirect treatment comparisons.

METHODS

A systematic literature review was conducted by searching MEDLINE, EMBASE, and the Cochrane Library with no limitations applied on publication language or dates. Included studies were randomized controlled trials evaluating one or more of fingolimod, interferon beta-1a, interferon beta-1b, or glatiramer acetate in RRMS populations. Primary outcome was ARR. Data extraction included author, year, treatment, dosage, mean age, percentage females, duration of disease, Expanded Disability Status Scale (EDSS) score at baseline, relapses in 2 years prior to baseline, trial duration, relapse-related outcome, and definition of relapse. The indirect treatment comparisons were performed using a mixed-treatment comparison framework. ARR was analyzed as a Poisson outcome.

RESULTS

The relative ARRs, for each treatment versus fingolimod, estimated from our meta-analyses were 1.43 (glatiramer acetate 20 mg), 1.51 (interferon beta-1b 250 mcg), 1.55 (interferon beta-1a 44 mcg), 1.67 (interferon beta-1a 22 mcg), 1.93 (interferon beta-1a 30 mcg), and 2.32 (placebo). None of the 95% confidence intervals for these estimates overlapped unity, implying statistical significance of these findings.

LIMITATIONS

The key limitations of this study are the persisting heterogeneity even after adjusting for covariates and the variability in outcome definition across the included trials.

CONCLUSIONS

Our study demonstrated that fingolimod significantly reduces relapse frequency in patients with RRMS compared with current first-line disease-modifying therapies.

A comparative in vitro evaluation of the fermentation properties of prebiotic oligosaccharides

AIMS

Comparison of in vitro fermentation properties of commercial prebiotic oligosaccharides.

METHODS AND RESULTS

Populations of predominant gut bacterial groups were monitored over 24 h of batch culture through fluorescent in-situ hybridization. Short-chain fatty acid and gas production were also measured. All prebiotics increased the numbers of bifidobacteria and most decreased clostridia. Xylo-oligosaccharides and lactulose produced the highest increases in numbers of bifidobacteria whilst fructo-oligosaccharides produced the highest populations of lactobacilli. Galacto-oligosaccharides (GOS) resulted in the largest decreases in numbers of clostridia. Short-chain fatty acid generation was highest on lactulose and GOS. Gas production was lowest on isomalto-oligosaccharides and highest on inulin.

CONCLUSIONS

The oligosaccharides differed in their fermentation characteristics. Isomalto-oligosaccharides and GOS were effective at increasing numbers of bifidobacteria and lactate whilst generating the least gas.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study provides comparative data on the properties of commercial prebiotics, allowing targeting of dietary intervention for particular applications and blending of oligosaccharides to enhance overall functionality.

Fermentation properties of gentio-oligosaccharides

AIMS

To investigate the fermentation properties of gentio-oligosaccharides (GOS), as compared to fructo-oligosaccharides (FOS) and maltodextrin in mixed faecal culture.

METHODS AND RESULTS

The substrates were incubated in 24 h batch culture fermentations of human faecal bacteria. Fluorescent in situ hybridization was used to determine changes in populations of bifidobacteria, lactobacilli, clostridia, bacteroides, streptococci and Escherichia coli. Gas and short-chain fatty acid (SCFA) production was also measured. GOS gave the largest significant increases in bifidobacteria, lactobacilli and total bacterial numbers during the incubations. However, FOS appeared to be a more selective prebiotic as it did not significantly stimulate growth of bacterial groups which were not probiotic in nature. GOS and maltodextrin produced the highest levels of SCFA. Lowest gas production was seen with GOS and highest with FOS.

CONCLUSIONS

GOS possessed bifidogenic activity in vitro. Although fermentation of GOS was not as selective as FOS, gas production was lower. Gas production is often seen as an undesirable side effect of prebiotic consumption.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study has provided the first data on fermentation of GOS in mixed faecal culture. The study has also used molecular microbiology methods (FISH) to quantify bacterial groups. The data extend our knowledge of the selectivity of fermentation of oligosaccharides by the gut microflora.

Methods for assessing the potential of prebiotics and probiotics

Prebiotics and probiotics are microflora management tools designed to improve human health. Both are dietary materials that fortify components of the gut flora seen as 'beneficial'. Gut flora modulation is an important area of the nutritional sciences, however, it is imperative that reliable methodologies be used to determine efficacy. This review will discuss the current techniques used in prebiotic and probiotic research.