Bayesian random-effects meta-analysis model for normal data – Pubrica
-
Upload
pubricahealthcare -
Category
Services
-
view
0 -
download
0
description
Transcript of Bayesian random-effects meta-analysis model for normal data – Pubrica
-
Copyright © 2021 pubrica. All rights reserved 1
What is the Bayesian Random-Effects Meta-
Analysis Model for Normal Data
Dr. Nancy Agnes, Head, Technical Operations, Pubrica, [email protected]
I. INTRODUCTION
In healthcare studies, systematic reviews are valuable
sources of evidence. These are regarded as having a
high degree of evidence because they reduce bias
during the evaluation process, offer detailed evidence
regarding the efficacy of an experiment, and often
resolve uncertainty caused by contradictory findings
from various researches asking the same issue. Meta-
analysis is an effective computational method for
obtaining a single effect size by combining the
outcomes of multiple individual experiments. As a
result, the best level of proof is known to be a
systematic study with meta-analysis.The conventional
meta-analysis approach does not take into account
previous knowledge from outside sources. As a
result, a new approach to meta-analysis is established,
in which historical data is combined using Bayesian
principles. "The clear comparative use of external
data in the design, control, study, and understanding
of health care evaluation," according to the Bayesian
approach. The prior belief about the parameter, which
should be external to data, is one of the criteria of
Bayesian meta-analysis. The observed data were
paired with prior experience to provide new
information about the parameter of interest [1].
The focus of this article is to define how extensively
Bayesian methods have been used in meta-analysis,
benefits, and implementations.
II. BAYESIAN METHODS: THE PRINCIPLES
Standard statistical inference means that the sample
comes from a population with a fixed and undefined
parameter. The sample information is used to make
the whole parameter inference. On the other hand, the
Bayesian method treats parameters as random
variables with a probability distribution that reflects
our prior knowledge. The likelihood function is
summarised in the current data. The prior distribution
and probability function was merged using Bayesian
rules to produce the posterior distribution function
[2].
III. META-ANALYSIS CONCEPT IN BAYESIAN
METHOD
There are four basic stages in a Bayesian meta-
analysis [2]:
(1) Choosing the Right Priorities
The first step in Bayesian meta-analysis is to
summarise the proof that isn't based on observed
facts. This document reviews previous evidence and
assumptions about intervention's relative benefits.
Non-randomized experiments, invitro or invivo trials,
experimental studies, or personal views may be used
as verification. Since the parameters are called
unpredictable random variables, prior distributions
are applied to them.
(2) Current Evidence
The probability function of the parameters would be
composed of observable data or impact predictions
gathered from various studies asking the same query.
For both measurable and unobservable quantities, a
complete probability model is constructed.
(3) Posterior
The external information is then combined with the
current data to arrive at a current understanding of the
intervention's impact. As a result, the posterior
distribution is derived by combining the prior
distribution and the probability function. The revised
proof is another name for the posterior. In addition,
unlike conventional Meta-analysis, all inferences
should be based on the posterior distribution.
(4) Recapitulating In Bayesian Meta-analysis, the final step is to
summarise the posterior distribution. The posterior
distribution obtained is often of high dimension and
complexity, necessitating computer-based packages
(BUGS and WINBUGS) to execute the integrations.
Simulation techniques like Markov Chain Monte
Carlo are used to sample directly from the posterior
distribution.As a result, all summary figures, such as
mean, standard deviation, odds ratio, risk ratio, and so
on, are calculated using those samples. Instead of 95
percent confidence intervals, 95 percent accurate
intervals (2.5 percentile and 97.5 percentile of
posterior distribution) were measured. In Bayesian
meta-analysis, two methods are widely used, similar
to conventional meta-analysis: fixed-effect and
mailto:[email protected]://pubrica.com/services/research-services/systematic-review/https://pubrica.com/services/research-services/meta-analysis/https://pubrica.com/services/research-services/meta-analysis/
-
Copyright © 2021 pubrica. All rights reserved 2
random-effects models. The only difference between
Bayesian Meta-analysis and conventional meta-
analysis is that prior distributions for uncertain
parameters are defined.
IV. BAYESIAN META-ANALYSIS PROFITS AND
CONTRAINDICATIONS
In prior distribution, Bayesian meta-analysis
integrates all applicable historical data outside of the
litigation. They account for all uncertainties,
especially when determining a predictive distribution
for the true effect in a new sample. When there are a
limited number of studies involved, or when studies
have fewer case results, or when studies report only
the summary estimation rather than its variance,
Bayesian meta-analysis is sufficient. The posterior
distribution is optimal for any decision-making
situation [3], and the odds are more understandable
than p values.They also provide for the interpretation
of the likelihood or consequence of action. Prior
probabilities can be used as a sensitivity analysis [4]
instrument to search for robustness andanalyses and
calculate various theories [5]. The main drawback is
that as the number of parameters increases with the
number of experiments, imposing vague priors on all
parameters will lead to contradictory outcomes.
Different prior distributions provide different
outcomes. Researchers must exercise caution when
using informative priors since they may significantly
affect the posterior. The software's implementation
necessitates excellence.
V. FUTURE SCOPES
Due to Bayesian's clear methodology for integrating
external data, these approaches are commonly used in
network meta-analysis. One renders both direct and
indirect observations dependent on a generic
comparator and ranks interventions. However,
although software makes much of the work simpler, it
still necessitates many computational assistance and
skills.In the field of clinical trial proof synthesis,
Bayesian meta-analysis has gained attention. Because
public health interventions are geared to
geographically heterogeneous demographic, multi-
component interventions, context-specific, and
https://pubrica.com/academy/statistical/enhancing-pediatric-clinical-trial-feasibility-through-the-use-of-bayesian-statistics/
-
Copyright © 2021 pubrica. All rights reserved 3
various effects, it did not gain traction in
summarising them. The use of conventional meta-
analysis to combine the findings of such analyses has
not been thoroughly studied. A recent effort was
made to investigate the complexities of public health
approaches and create a meta-analysis for public
health interventions that took complexity into
account.Any public health intervention's data is
typically obtained from a mixture of retrospective and
interventional trials. Since there is no common
mechanism for combining the findings of
retrospective and intervention trials, most systematic
analyses are presented narratively. As a result, in
complicated public health research, a reliable method
of evidence synthesis is needed. Finally, Bayesian
meta-analysis-specific reporting criteria must be
established.
REFERENCE
[1] Lewis, Melissa Glenda and Nair, Sreekumaran
N (2015) Review of applications of Bayesian meta-
analysis in systematic reviews. Global Journal of
Medicine and Public Health, 4 (1). pp. 1-9. ISSN
2277-9604.
[2]
MatthaisE,GeorgeDS,JonathanAC(2002).Systematicr
eviews and Meta-‐analysis. In: Oxford textbook of
Public Health.4th
ed. New York: Oxford University
press.
[3]Młynarczyk, Dorota; Armero, Carmen; Gómez-
Rubio, Virgilio; Puig, Pedro. 2021. "Bayesian
Analysis of Population Health Data" Mathematics 9,
no. 5: 577. https://doi.org/10.3390/math9050577.
[4]Mojtaba GANJALI, Taban BAGHFALAKI,
Adeniyi Francis FAGBAMIGBE "A Bayesian
sensitivity analysis of the effect of different random
effects distributions on growth curve models,"
AfrikaStatistika, Afr. Stat. 15(3), 2387-2393, (July
2020)
[5]Paulewicz, B., Blaut, A. The bhsdtr package: a
general-purpose method of Bayesian inference for
signal detection theory models. Behav Res 52, 2122–
2141 (2020). https://doi.org/10.3758/s13428-020-
01370-y.
https://pubrica.com/academy/medical-writing/meta-analysis-of-convolutional-neural-networks-for-radiological-images/https://pubrica.com/academy/medical-writing/meta-analysis-of-convolutional-neural-networks-for-radiological-images/https://doi.org/10.3390/math9050577https://doi.org/10.3758/s13428-020-01370-yhttps://doi.org/10.3758/s13428-020-01370-y