Review of applications of Bayesian meta-analysis in systematic reviews

Background: Systematic reviews are important sources of evidence in health care research. These reviews may or may not include meta-analysis as a statistical assimilation of the results of several studies in order to acquire a pooled estimate. Systematic review with meta-analysis is considered as a robust method of evidence synthesis. The methodology concerned with traditional meta-analysis does not incorporate external prior information. Hence, Bayesian methods are essential due to the natural process of incorporating the past information and updating the belief. Bayesian methods to meta-analysis have been developed with a motivation from the limitations of traditional meta-analysis such as dealing with missing data, problem with limited number of studies and problem with sparse event data in both the groups. The present article aims to unearth as to what extent Bayesian methods have been used in systematic reviews, evolution and its applications. This article also highlights the existing challenges and opportunities. Methods: The literature search was performed in databases such as Cochrane, PubMed, ProQuest and Scopus using the keywords “Bayesian Meta-analysis” and “Bayesian Meta-analyses”. All the methodology and application oriented papers specific to Bayesian meta-analysis were considered relevant for this review. Conclusion: Bayesian meta-analysis has gained popularity in the field of evidence synthesis of clinical trials. However, it did not pick up momentum in summarizing public health interventions, owing to the fact that public health interventions are targeted to highly heterogeneous population, multi-component interventions, and multiple outcomes and influenced by the contex

Outcomes of Visceral Arterial Reconstruction: A Systematic Review

Aims: The study aimed to review the use of synthetic grafts (SGs) and autologous vein grafts (AVGs) in visceral arterial reconstruction (VAR) in chronic visceral ischaemia. Methods: Systematic review methodology was employed. Results: Six studies were included (218 patients and 281 vessels). Two studies had data about AVG only, 3 had data about SG only and 1 had both AVG and SG data. Three studies reported outcomes for AVG (117 patients and 132 vessels revascularized). One-year primary patency was 87% (95% CI 71%, 97%). Graft thrombosis rate was 6% (95% CI 0%, 16%). Pooled stenosis rate at one-year was 11% (95% CI 1%, 28%). The 30-day (n = 96), one-year (n = 72) and 5-year mortality (n = 30) were 0%, 0% and 12%, respectively. Four studies reported outcomes for SGs (106 patients and 147 vessels). The pooled primary patency at one year was 100% (95% CI 99%, 100%). Pooled primary 5-year patency rate was 88% (95% CI 69%, 100%). There was no graft infection in 2 of the 3 studies. Overall pooled percentage of graft thrombosis and stenosis at one year was 0%. Jimenez et al. (2002) reported one graft thrombosis at 20 months and graft stenosis in 2 patients at 46 and 49 months. Illuminati et al (2017) reported graft thrombosis in 2/24 patients at 22 and 52 months. Thirty days, one-year and 5-year mortality was 1% (95% CI 0%, 6), 7% (95% CI 0%, 20%) and 39% (95% CI 11%), respectively. Conclusion: Patency was better with SG compared with AVG. Mortality was higher in the SG group. Graft dilatation does occur with vein grafts, but in this review no intervention was found necessary. Poorly designed studies, incomplete reporting and absence of morbidity and mortality indices preclude emphatic conclusions

Evaluation of the Impact of the First Wave of COVID-19 and Associated Lockdown Restrictions on Persons with Disabilities in 14 States of India

Background: There is a paucity of data to assess the impact of the COVID-19 pandemic on persons with disabilities (PwDs) in India. About 27.4 million cases were reported as of 27 May 2021. The continuing pandemic in the form of subsequent waves is expected to have negative repercussions for the disabled globally, particularly in India, where access to health, rehabilitation, and social care services is very limited. Therefore, this study aimed to assess the impact of the COVID-19 pandemic and lockdown restrictions on PwDs in India. Objective: To determine the level of disruption due to COVID-19 and the associated countrywide lockdown restrictions on PwD in India during the first wave. Methods: Using a cross-sectional, mixed-methods approach, data were collected from a representative sample of 403 persons with disabilities in 14 states in India during the COVID-19 first wave at two different points in time (Lockdown and post-lockdown phase). Factors associated with the negative impact were examined using the Chi-square test for associations. The paired comparisons between ‘lockdown’ with the ‘post-lockdown’ phase are presented using McNemar’s test and the marginal homogeneity test to compare the proportions. Additionally, a subsample of the participants in the survey was identified to participate in in-depth interviews and focus group discussions to gain in-depth insights on the study question and substantiate the quantitative findings. The framework approach was used to conduct a thematic analysis of the qualitative data. Results: About 60 of the PwDs found it difficult to access emergency medical services during the lockdown, and 4.6 post lockdown (p < 0.001). Likewise, 12 found it difficult to access rehabilitation services during the lockdown, and 5 post lockdown (p = 0.03). About 76 of respondents were apprehensive of the risk of infection during the lockdown, and this increased to 92 post lockdown (p < 0.001). Parents with children were significantly impacted due to lockdown in the areas of Medical (p = 0.007), Rehabilitation (p = 0.001), and Mental health services (p = 0.001). The results from the qualitative study supported these quantitative findings. PWDs felt that the lockdown restrictions had negatively impacted their productivity, social participation, and overall engagement in everyday activities. Access to medicines and rehabilitation services was felt to be extremely difficult and detrimental to the therapeutic benefits that were gained by them during the pre-pandemic time. None of the pandemic mitigation plans and services was specific or inclusive of PWDs. Conclusions: COVID-19 and the associated lockdown restrictions have negatively impacted persons with disabilities during the first wave in India. It is critical to mainstream disability within the agenda for health and development with pragmatic, context-specific strategies and programs in the country

Do Gestational Obesity and Gestational Diabetes Have an Independent Effect on Neonatal Adiposity? Results of Mediation Analysis from a Cohort Study in South India.

PURPOSE: Neonates born to mothers with obesity or gestational diabetes mellitus (GDM) have an increased chance of various metabolic disorders later in life. In India, it is unclear whether maternal obesity or GDM is related to offspring adiposity. We aimed to understand the independent effect of maternal obesity and GDM with neonatal adiposity and whether GDM has a mediating effect between maternal obesity and neonatal adiposity. METHODS: We recruited a cohort of 1120 women (between April 2016 and February 2019) from the public hospitals in Bangalore, India, who voluntarily agreed to participate and provided written informed consent. The primary outcome was neonatal adiposity, defined as the sum of skinfold thickness >85th percentile. Exposure included maternal obesity, defined as >90th percentile of skinfold thickness. GDM, the potential mediator, was classified using the World Health Organization criteria by oral glucose tolerance test. Binary logistic regression was applied to test the effect of maternal obesity and GDM on neonatal adiposity, adjusting for potential confounders. We used Paramed command in STATA version 14 for analyzing mediating effects. RESULTS: We found that maternal obesity (odds ratio (OR)=2.16, 95% CI 1.46, 3.18) and GDM (OR=2.21, 95% CI1.38, 3.52) have an independent effect on neonatal adiposity. GDM significantly mediates 25.2% of the total effect between maternal obesity and neonatal adiposity, (natural direct effect OR = 1.16 95% CI 1.04, 1.30) with significant direct effect of maternal obesity (natural direct effect OR = 1.90 95% CI 1.16, 3.10) and significant total effect (OR=2.20 95% CI 1.35, 3.58). CONCLUSION: We showed that maternal obesity and GDM are independently associated with offspring adiposity. Also, GDM mediates the association of maternal obesity on adiposity in children. Interventions focused on obesity prevention in women, and effective screening and management of GDM may contribute to reducing childhood obesity in India

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Review of applications of Bayesian meta-analysis in systematic reviews

Background: Systematic reviews are important sources of evidence in health care research. These reviews may or may not include meta-analysis as a statistical assimilation of the results of several studies in order to acquire a pooled estimate. Systematic review with meta-analysis is considered as a robust method of evidence synthesis. The methodology concerned with traditional meta-analysis does not incorporate external prior information. Hence, Bayesian methods are essential due to the natural process of incorporating the past information and updating the belief. Bayesian methods to meta-analysis have been developed with a motivation from the limitations of traditional meta-analysis such as dealing with missing data, problem with limited number of studies and problem with sparse event data in both the groups. The present article aims to unearth as to what extent Bayesian methods have been used in systematic reviews, evolution and its applications. This article also highlights the existing challenges and opportunities. Methods: The literature search was performed in databases such as Cochrane, PubMed, ProQuest and Scopus using the keywords “Bayesian Meta-analysis” and “Bayesian Meta-analyses”. All the methodology and application oriented papers specific to Bayesian meta-analysis were considered relevant for this review. Conclusion: Bayesian meta-analysis has gained popularity in the field of evidence synthesis of clinical trials. However, it did not pick up momentum in summarizing public health interventions, owing to the fact that public health interventions are targeted to highly heterogeneous population, multi-component interventions, and multiple outcomes and influenced by the contex

Paraquat – Boon or bane? A retrospective study of paraquat poisoning and outcomes in a tertiary care center in South India

Setting: Paraquat is a highly toxic, herbicide, extensively used in various parts of India. There is no effective treatment for paraquat poison and carries a very high mortality. In India, this compound can be misused for harmful purposes. Objective: A retrospective time-bound descriptive study of paraquat-consumed patients was conducted at Kasturba Hospital, Manipal, from January 1, 2014 to January 31, 2016. Materials and Methods: All the data were analyzed using the SPSS version 16. All the categorical data are expressed in terms of frequency and percentage. Continuous normal variables were expressed in terms of mean ± standard deviation, and skewed variables were expressed in terms of median and quartiles. Chi-square test was used to find the association between the categorical independent variables across the outcome in survivors, nonsurvivors, and those patients who were discharged from the hospital against medical advice. Similarly, Fisher's exact test was performed for those variables, for which 20% of the expected cell count was <5%. Kruskal–Wallis test was used to compare the relationship between the continuous skewed variables across the outcome. Results: A total of 55 paraquat-consumed patients were admitted, out of which 67.27% (n = 37) of patients were men. Only 32.7% (n = 18) of patients were farmers. Oral ulcers were seen in 43.6% (n = 24) of patients. About 65.5% (n = 36) of patients underwent hemoperfusion, 27.3% (n = 15) of patients survived, 47.3% (n = 26) of patients expired, and 25.5% (n = 14) of patients were discharged against medical advice in a critical condition. The presence of respiratory failure, hypotension, need for ventilator supportive therapy, the elevation of levels of blood urea, serum creatinine, and liver enzymes AST and ALT levels were statistically significant in three groups (P < 0.001). Conclusion: Paraquat poisoning is highly fatal. Treatment is expensive and available only in tertiary care hospitals in India. Central and state governments should ensure that it should not be readily accessible to ordinary people and it should be banned progressively

Distracted driving: Direct observation of mobile phone use among motorised two-wheeler drivers in the rapidly motorising city of Hyderabad, India

Introduction: Mobile phone use in India is increasing exponentially, accompanied by rapid motorization. We estimated the factors influencing mobile phone use among motorised two-wheeler (MTW) drivers in the rapidly motorizing city of Hyderabad, India. Methods: Using a proforma observation checklist, 15-min observations were conducted. The vehicle flow was video recorded during the entire duration for confirmation. Poisson regression (robust variance) was used to calculate prevalence ratios (PR) and 95% CI for the association between mobile phone use and various factors (the type of road, time of day, and week). Results: Mobile phone use among 11787 MTW drivers observed was 16.49% (95% CI 15.83%–17.17%), a majority in ‘hands-free’ mode. It was higher on weekends than weekdays (adjusted PR = 1.44, 95% CI 1.30 to 1.59); on Non-busy roads than Busy roads (PR = 1.43, 95% CI 1.29 to 1.58) and on Non-Peak hour than Peak-hour (PR = 1.29, 95% C I 1.16 to 1.43) after adjusting for other factors. Conclusions: Type of road, day, and time were significant factors affecting mobile phone use among MTW in Hyderabad, it being almost one and half times higher on non-busy roads, non-peak time, and during weekends. These findings are especially important in a rapidly motorizing urban context. Penalties for both hand-held and hands-free mobile phone use must be included in the newly amended Motor Vehicle Act of India, with strict, consistent, and visible enforcement