Meta-analysis Of Long-term Studies Research Articles

A systematic review and meta-analysis of long-term studies (≥5-years) assessing maxillary sinus floor augmentation

Background: Maxillary sinus floor augmentation is the most frequently used method to enhance the alveolar bone height of the posterior maxilla before or in conjunction with implant placement. Autogenous bone graft is considered the golden standard for bone augmentation. However, harvesting of autogenous bone grafts is associated with risk of donor site morbidity and unpredictable graft resorption. Hence, various bone substitutes are used increasingly to simplify the surgical procedure.

Nitrogen dioxide and mortality: review and meta-analysis of long-term studies

Exposure to ambient nitrogen dioxide (NO2) has been linked to increased mortality in several epidemiological studies but the question remains of whether NO2 is directly responsible for the health effects or is only an indicator of other pollutants, including particulate matter. The aim of the present review was to provide pooled estimates of the long-term effects of NO2 on mortality, which are potentially useful for health impact assessment. We selected 23 papers, published from 2004 to 2013, evaluating the relationship between NO2 and mortality, also including an assessment of the effect of particulate matter exposure. A random-effects meta-analysis was carried out on 19 studies. The pooled effect on mortality was 1.04 (95% CI 1.02-1.06) with an increase of 10 μg · m(-3) in the annual NO2 concentration and 1.05 (95% CI 1.01-1.09) for particulate matter <2.5 μm in diameter (PM2.5) (10 μg · m(-3)). The effect on cardiovascular mortality was 1.13 (95% CI 1.09-1.18) for NO2 and 1.20 (95% CI 1.09-1.31) for PM2.5. The NO2 effect on respiratory mortality was 1.03 (95% CI 1.02-1.03) and 1.05 (95% CI 1.01-1.09) for PM2.5. Four bipollutant analyses with particulate matter and NO2 in the same models showed minimal changes in the effect estimates of NO2. There is evidence of a long-term effect of NO2 on mortality as great as that of PM2.5. An independent effect of NO2 emerged from multipollutant models.

Nitrogen dioxide and mortality: review and meta-analysis of long-term studies

Background. Exposure to nitrogen dioxide (NO2) has been linked to increased mortality in several epidemiological studies on both short and long-term effects. The question whether NO2 is directly responsible for the health effects, or it is only an indicator for other pollutants (mainly particulate matter) remains to be assessed. Aim. We have reviewed the more recent studies evaluating the long-term effects of NO2 on mortality to provide a quantitative summary of the effects potentially useful for health impact assessment. Methods. Original studies exploring the relationship between long-term NO2 exposure and mortality, and including also PM effects, were searched in PubMed, Web of Science and LUDOK. Twenty-seven papers published in 2004-2012 were selected. A meta-analysis was carried out on 19 studies, with different study design, estimating random effects relative risks. Results.The pooled effect on mortality was 1.05 (95% confidence intervals = 1.02-1.07) for 10µg/m3 of NO2 annual concentration. The corresponding effect for PM2.5 (10µg/m3 ) was 1.05 (95%CI=1.03-1.08). The effect on cardiovascular mortality (CV) was 1.14 (95%CI=1.10-1.19) for NO2 and 1.22 (95%CI=1.10-1.35) for PM2.5. The NO2 effect on respiratory mortality was 1.03 (95%CI1.02-1.03), whereas the effect of PM2.5 was 1.05% (95%CI 1.004-1.104). The five carried-out bi-pollutant analyses showed no changes of NO2 effects in comparison to the single-pollutant estimates. The NO2 effects were stronger in Asia and Europe than in North America. Conclusions.There is evidence for a long-term effect of NO2 on natural mortality as high as that of PM2.5. An independent effect of NO2 emerged, though explored only in few studies. The associations of NO2 with mortality differed across the areas of the world.

Essential Oils Compared to Chlorhexidine With Respect to Plaque and Parameters of Gingival Inflammation: A Systematic Review

The purpose of this review is to systematically evaluate the effects of an essential-oil mouthwash (EOMW) compared to a chlorhexidine mouthwash with respect to plaque and parameters of gingival inflammation. PubMed/MEDLINE and Cochrane CENTRAL databases were searched for studies up to and including September 2010 to identify appropriate articles. A comprehensive search was designed, and the articles were independently screened for eligibility by two reviewers. Articles that evaluated the effects of the EOMW compared to chlorhexidine mouthwash were included. Where appropriate, a meta-analysis was performed, and weighted mean differences (WMDs) were calculated. A total of 390 unique articles were found, of which 19 articles met the eligibility criteria. A meta-analysis of long-term studies (duration ≥ 4 weeks) showed that the chlorhexidine mouthwash provided significantly better effects regarding plaque control than EOMW (WMD: 0.19; P = 0.0009). No significant difference with respect to reduction of gingival inflammation was found between EOMW and chlorhexidine mouthwash (WMD: 0.03; P = 0.58). In long-term use, the standardized formulation of EOMW appeared to be a reliable alternative to chlorhexidine mouthwash with respect to parameters of gingival inflammation.

Meta-analysis of long-term studies to assess the effect of acarbose on cardiovascular risk reduction ? scientifically credible: Reply

The authors criticised our meta-analysis of seven long-term studies to assess the effect of acarbose on cardiovascular risk reduction. Two different approaches are generally accepted as standard procedures for meta-analyses.1 These are systematic literature reviews or meta-analyses of all randomised controlled trials. Our meta-analysis is based on the latter approach. As clearly stated in our article, data from all randomised, double-blind, placebo-controlled clinical trials with a minimum treatment duration of 52 weeks were included. The source was the Bayer Acarbose clinical database. As a consequence, publication and selection bias (regarded as substantial risks in the situation of systematic literature review) …