meta regression

The prevalence of childhood obesity has been on an increasing trend in the world during the past decades, with studies in Iran showing different and inconsistent prevalence rates. 

This study was done to determine the prevalence of obesity in children through a meta-analysis approach.

This study was done to determine the prevalence of obesity in children through a meta-analysis approach from January 2000 to January 2021. Articles related to the subject were obtained by searching Scopus, ScienceDirect, SID, Magiran, Barakat Knowledge Network System, Medline (PubMed), and Google Scholar databases. The heterogeneity of the studies was evaluated using the I2 index and the data were analyzed by Comprehensive Meta-analysis software. 

In a study on 2,637,912 individuals aged 2-15 years, the overall prevalence of obesity in Iranian children was 11.4% (95% CI: 9.4-13.7%) based on a meta-analysis. Also, in order to investigate the effects of potential factors (sample size and year of study) on the heterogeneity of obesity prevalence in Iranian children, meta-regression was used. It was reported that the prevalence of obesity in Iranian children decreased and increased with increasing sample size and increasing years of the study, respectively, and both were significantly different from each other (P<0.05).

Considering the high prevalence of obesity in Iranian children, it is necessary for health policymakers to take effective educational measures.

Coordinate-based meta-analysis (CBMA) is a standard method for integrating brain functional patterns in neuroimaging studies. CBMA aims to identify convergency in activated brain regions across studies using coordinates of the peak activation (foci). Here, we aimed to introduce a new application of the Gibbs models for the meta-regression of the neuroimaging studies.

We used a dataset acquired from 31 studies by previous work. For each study as well as foci, study features such as SD duration and the average age were extracted. Two widely Gibbs models, Area-interaction and Geyer saturation were fitted on the foci. These models can quantify and test evidence for clusters in foci using an interaction parameter. We included study features in the models to identify their contribution to foci distribution and hence determine sources of the heterogeneity.

Our results revealed that latent study-specific features have a moderate contribution to the heterogeneity of foci distribution. However, the effect of age and SD duration was not significant (p<0.001). Additionally, the estimated interaction parameter was 1.34 (p<0.001) which denotes strong evidence of clusters in foci.

Overall, this study highlighted the role of the interaction parameter in CBMA. The results of this work suggest that Gibbs models can be considered as a promising tool for neuroimaging meta-analysis.

Unrecognized congenital hypothyroidism (CH) leads to mental retardation. Newborn screening and thyroid therapy started within 2 weeks of age can normalize cognitive development. In this systematic review, the local results of the national CH screening program in different provinces in Iran are reviewed and evaluated. Literature on the CH screening, the national databases including SID, Medlib, Iran Medex, Magiran as well as international databases including PubMed/Medline, ISI Web of Knowledge and web of science, EMBASE, SCOPUS and Google Scholar. Appraisal was guided by a checklist assessing clarity of aims and research questions. The 95% confidence intervals were calculated by I-square models. Meta regression was introduced to explore the heterogeneity between studies. We identified 25 samples including 1425124 neonates in our country. Data were Meta analyzed using random-effects models, and we found a TSH levels of 19633 babies in the first sampling were greater than the cut-off level (TSH ≥5mIU/L). The pooled recall rate was 0.014 (95 % CI: 0.013 – 0.015). According to Meta analysis the overall incidence of CH was 2/1000 (95% CI:. 002 –. 002). The incidence of CH did not appear to be increasing over time (P=0.08). Considering TSH ≥5mIU/L as a cut-off point for recalling neonates and low positive predictive value (14%) of this point shows that more investigation and research is needed for establishing accurate level of TSH as a criterion for recalling patients.

Hepatitis B infection is an important health problem all over the world, and according to the studies, Iran is a country with intermediate prevalence, so vaccination is a cost-benefit approach. In this study, evidence about the efficacy of hepatitis B vaccine was collected by systematic review methods and its amount was estimated by a meta-analysis.

In this study, documents and literature search were performed using valid key words in Information Sciences Institute, PubMed, Scientific Information Data base, and Iranmedex databases from 1997 to 2010 in different regions of Iran. All cross-sectional studies about the efficacy of hepatitis B vaccine in Iran which fulfilled the inclusion criteria entered the study. Antibody titer (Anti-hemoglobins > 10 IU/L) was considered as the desired efficacy. In order to present the results, prevalence and Forest plot were used and for evaluation of the inconsistency meta-regression model and I 2 index were used. We used R.15.3.2 software for analysis.

Totally 64 studies (52 studies in general population and 12 studies among specific populations) including 12,575 subjects with age range from 8 months to 55 years entered the meta-analysis. The efficacy was 86.3% (confidence interval [CI]: 83.9-88.7%) in the general population and 59.62% (CI: 47.9-71.29%) in specific patient populations. Also the efficacy was significantly related to the year of publication, age and gender (P < 0.05).

Prevention is an important issue in general health. Hepatitis B vaccination is one of the methods used to prevent hepatitis B infection. According to this study, the efficacy of hepatitis B vaccination was more than 80% in general population, so injection of full course of hepatitis B vaccinationis enough and booster dose is not required.