Smoking increases risk of tooth loss: A meta-analysis of the literature

AIM: To quantitatively evaluate the impact of smoking on tooth loss.

METHODS: We performed a PubMed search to identify published articles that investigated the risk of tooth loss by smoking, from which RRs and their variance with characteristics of each study were extracted. The random-effects models were used to derive a pooled effect across studies. Potential sources of heterogeneity on the characteristics of the study and their influence on the pooled effect size were investigated using meta-regression models.

RESULTS: We identified 24 studies containing a total of 95973 participants for analysis. The pooled RR of ever-smokers compared with never- smokers was 1.73 (95%CI: 1.60-1.86, P < 0.001). In meta-regression analysis, only the mean age of participants alone was identified as a statistically significant source of heterogeneity. The effect of smoking on tooth loss was stronger when the mean age of study participants was higher, indicating possible enhancement of tooth loss due to aging by smoking. RR was significantly lower in former smokers (1.49, 95%CI: 1.32-1.69, P < 0.001) than in current smokers (2.10, 95%CI: 1.87-2.35, P < 0.001), indicating the substantial benefit of smoking cessation for reducing the risk of tooth loss.

CONCLUSION: Smoking is an independent risk factor for tooth loss regardless of many other confounders. Smoking cessation may attenuate this effect.

What is the purpose of launching World Journal of Meta-Analysis?

The exponential growth of scientific evidence (i.e., primary research) and the ongoing development of methods to summarize such evidence, such as meta-analyses and mixed treatment comparisons (i.e., secondary research), make the worldwide dissemination of high-quality meta-analyses and pertinent articles a key scientific priority. The World Journal of Meta-Analysis will apply an electronic open access publishing approach combined with a timely and thorough peer-review of submitted manuscripts, weighing more on quality than priority, in order to improve the dissemination of systematic reviews and meta-analyses, as well as novelties and advancements in methods related to them, focusing on clinical medicine, but spanning all biomedical, epidemiological, and psychological research fields.

Meta-analyses in the wonderland of neurology

Meta-analyses are often misused and underused in neurology. This editorial provides some comments on the role of meta-analyses in neurological research. Recently, a huge increase in the number of meta-analyses and systematic reviews has been observed in neurological journals. The major strengths of meta-analyses are the increase of statistical power. However, as for any other investigative tool, meta-analytic research is a research method itself which can produce severe shortcomings. Specifically, the issues of search terms, time periods of published studies, databases used for searching, the definitions of inclusion and exclusion criteria for papers (which greatly affect clinical heterogeneity), publication bias; and the statistical methods used, dramatically influence the results of meta-analyses. The main problem of meta-analyses is that they cannot be expected to overcome the limitations of the studies they include (the so-called “garbage in, garbage out” phenomenon). Furthermore, most systematic reviews in the neurological literature lead to the unsatisfying and clinically frustrating statement “further studies are needed”. However it is much more frustrating to see how the gaps in scientific knowledge identified by meta-analyses have not been translated into serious efforts to fill them. Besides their role in evaluating efficacy and tolerability of drugs, meta-analyses may be used to assess diagnostic values of debatable clinical findings, as they represent powerful tools to try to answer questions not posed by individual studies and to settle controversies arising from conflicting claims.

Sirturo (Bedaquiline): The first new anti tubercular drug in decades

Tuberculosis (TB) is an infection caused by Mycobacterium tuberculosis and is one of the world’s deadliest diseases. Multidrug resistant TB (MDR-TB) is a serious form of TB and it implies resistance for at least two essential first-line agents like, Isoniazid and Rifampicin. The US Food and Drug Administration (FDA) granted accelerated approval to Janseen Therapeutics “Sirturo (Bedaquiline)”, a diarylquinoline anti mycobacterial drug on December 28, 2012 as part of combination therapy in adults (≥ 18 years) to treat MDR-TB when other alternatives are not available. The FDA also granted Sirturo fast track designation, priority review and orphan-product designation. Bedaquiline inhibits mycobacterial ATP (adenosine 5’-triphosphate) synthase, an enzyme that is essential for the generation of energy in Mycobacterium tuberculosis.

Effectiveness of rehabilitation based on recreational activities: A systematic review

AIM: To summarize the evidence from randomized controlled trials (RCTs) on the rehabilitation effects of recreational activities.

METHODS: Studies were eligible if they were RCTs. Studies included one treatment group in which recreational activity was applied. We searched the following databases from 1990 to May 31, 2012: MEDLINE via PubMed, CINAHL, Web of Science, and Ichushi-Web. We also searched all Cochrane Databases and Campbell Systematic Reviews up to May 31, 2012.

RESULTS: Eleven RCTs were identified, which included many kinds of target diseases and/or symptoms such as stroke, dementia, Parkinson’s disease, acquired brain injury, chronic non-malignant pain, adolescent obesity, high-risk pregnancy, and the frail elderly. Various intervention methods included gaming technology, music, dance, easy rider wheelchair biking, leisure education programs, and leisure tasks. The RCTs conducted have been of relatively low quality. A meta-analysis (pooled sample; n = 44, two RCTs) for balance ability using tests such as “Berg Balance Scale” and “Timed Up and Go Test” based on game intervention revealed no significant difference between interventions and controls. In all other interventions, there were one or more effects on psychological status, balance or motor function, and adherence as primary or secondary outcomes.

CONCLUSION: There is a potential for recreational activities to improve rehabilitation-related outcomes, particularly in psychological status, balance or motor function, and adherence.