This document provides an overview of a meta-analysis workshop. It will introduce descriptive and inferential statistics, the concept of meta-analysis, and meta-analysis software and models. The workshop covers new topics like quality effects meta-analysis, heterogeneity models, and assessment of publication bias. It explains that simply averaging study results is incorrect, and meta-analysis statistically combines studies while weighting them by size and power to provide a single pooled effect estimate. Meta-analysis has advantages like larger power but must address heterogeneity and differences between studies.
Meta-analysis in Epidemiology is:
Useful tool for epidemiological studies which investigates the relationships between certain risk factors and disease.
Useful tool to improve animal well-being and productivity
Despite of a wealth of suitable studies it is relatively underutilized in animal and veterinary science.
Meta-analysis can provide reliable results about diseases occurrence, pattern and impact in livestock.
It is utmost essential to take benefit of this statistical tool for produce. more reliable estimates of concern effects in animal and veterinary science data.
Summary slides for "Systematic Review and Meta-Analysis Course for Healthcare Professionals", January 8-9, 2013, King Abdullah Medical City, Makkah, Saudi Arabia
http://KAMCResearch.org
Meta-analysis in Epidemiology is:
Useful tool for epidemiological studies which investigates the relationships between certain risk factors and disease.
Useful tool to improve animal well-being and productivity
Despite of a wealth of suitable studies it is relatively underutilized in animal and veterinary science.
Meta-analysis can provide reliable results about diseases occurrence, pattern and impact in livestock.
It is utmost essential to take benefit of this statistical tool for produce. more reliable estimates of concern effects in animal and veterinary science data.
Summary slides for "Systematic Review and Meta-Analysis Course for Healthcare Professionals", January 8-9, 2013, King Abdullah Medical City, Makkah, Saudi Arabia
http://KAMCResearch.org
A meta-analysis is the use of statistical methods to summaries the results of the studies. Meta-analyses are conducted to assess the strength of evidence present on a disease and treatment. The results of a meta-analysis can improve precision of estimates of effect, answer questions not posed by the individual studies, settle controversies arising from apparently conflicting studies, and generate new hypotheses. In particular, the examination of heterogeneity is vital to the development of new hypotheses.
Basics of Systematic Review and Meta-analysis: Part 3Rizwan S A
Â
A 4 part lecture series on the basics of Systematic Review and Meta-analysis, Part 3 discusses the software needed and analytical techniques used for this purpose.
Study designs, Epidemiological study design, Types of studiesDr Lipilekha Patnaik
Â
Study design, Epidemiological study designA study design is a specific plan or protocol
for conducting the study, which allows the investigator to translate the conceptual hypothesis into an operational one.
A meta-analysis is the use of statistical methods to summaries the results of the studies. Meta-analyses are conducted to assess the strength of evidence present on a disease and treatment. The results of a meta-analysis can improve precision of estimates of effect, answer questions not posed by the individual studies, settle controversies arising from apparently conflicting studies, and generate new hypotheses. In particular, the examination of heterogeneity is vital to the development of new hypotheses.
Basics of Systematic Review and Meta-analysis: Part 3Rizwan S A
Â
A 4 part lecture series on the basics of Systematic Review and Meta-analysis, Part 3 discusses the software needed and analytical techniques used for this purpose.
Study designs, Epidemiological study design, Types of studiesDr Lipilekha Patnaik
Â
Study design, Epidemiological study designA study design is a specific plan or protocol
for conducting the study, which allows the investigator to translate the conceptual hypothesis into an operational one.
How Randomized Controlled Trials are Used in Meta-Analysis Pubrica
Â
Randomized Controlled Trials (RCTs) are a commonly used research design in medical and scientific studies to assess the effectiveness of interventions or treatments. Meta-analysis, on the other hand, is a statistical technique used to combine and analyze the results of multiple studies on a particular topic to draw more robust conclusions.
Continue reading @ https://pubrica.com/academy/meta-analysis/how-randomized-controlled-trials-are-used-in-meta-analysis/
For all your research assistance visit us @ https://pubrica.com/services/research-services/
Available online at www.sciencedirect.comN u r s O u t l o o.docxcelenarouzie
Â
Available online at www.sciencedirect.com
N u r s O u t l o o k 6 0 ( 2 0 1 2 ) 1 8 2 e 1 9 0
www.nursingoutlook.org
Using meta-analyses for comparative effectiveness
research
Vicki S. Conn, PhD, RN, FAAN*, Todd M. Ruppar, PhD, RN, GCNS-BC,
Lorraine J. Phillips, PhD, RN, Jo-Ana D. Chase, MN, APRN-BC
Meta-Analysis Research Center, School of Nursing, University of Missouri, Columbia, MO
a r t i c l e i n f o
Article history:
Received 30 December 2011
Revised 16 April 2012
Accepted 22 April 2012
Keywords:
Comparative effectiveness
research
Meta-analysis
* Corresponding author: Dr. Vicki S. Conn, A
Center, S317 School of Nursing, University o
E-mail address: [email protected] (V.S.
0029-6554/$ - see front matter ďż˝ 2012 Elsevi
doi:10.1016/j.outlook.2012.04.004
a b s t r a c t
Comparative effectiveness research seeks to identify the most effective inter-
ventions for particular patient populations. Meta-analysis is an especially
valuable form of comparative effectiveness research because it emphasizes the
magnitude of intervention effects rather than relying on tests of statistical
significance among primary studies. Overall effects can be calculated for diverse
clinical and patient-centered variables to determine the outcome patterns.
Moderator analyses compare intervention characteristics among primary
studies by determining whether effect sizes vary among studies with different
intervention characteristics. Intervention effectiveness can be linked to patient
characteristics to provide evidence for patient-centered care. Moderator anal-
yses often answer questions never posed by primary studies because neither
multiple intervention characteristics nor populations are compared in single
primary studies. Thus, meta-analyses provide unique contributions to knowl-
edge. Although meta-analysis is a powerful comparative effectiveness strategy,
methodological challenges and limitations in primary research must be
acknowledged to interpret findings.
Cite this article: Conn, V. S., Ruppar, T. M., Phillips, L. J., & Chase, J.-A. D. (2012, AUGUST). Using meta-
analyses for comparative effectiveness research. Nursing Outlook, 60(4), 182-190. doi:10.1016/
j.outlook.2012.04.004.
Despite remarkable scientific advances over recent
decades, the effectiveness of many health interven-
tions remains unclear. The Institute of Medicine noted
that evidence of effectiveness exists for less than half of
the interventions in use today.1 Scant evidence exists
comparing multiple possible interventions for the same
health problem.2 Newer or more costly interventions
may not be linked with better outcomes, and variations
in health care expenditure may be unrelated to changes
in health outcomes.3-5 The troubling lack of information
about interventionsâ relative effectiveness led to
comparative effectiveness research (CER) initiatives.
ssociate Dean & Potter-B
f Missouri, Columbia, MO
Conn).
er Inc. All rights reserved
CER can be defined as research designed to discov.
Clinical Research for Medical StudentsAhmed Negida
Â
This presentation discusses (1) the importance of clinical research to medical students, (2) barriers towards student research, and (3) how to select a good mentor.
How to write a biomedical research paperAhmed Negida
Â
This was the presentation of (How to write a biomedical research day workshop) given by Ahmed Negida as a part from MRGE continuous research activities in Egypt.
The course was joined by 45 medical students and seniors from different Egyptian Universities and it was more than 6 hours of exciting learning activities.
Major Learning Objectives were:
1- Structure of biomedical Research Paper
2- How to Write a conference Abstract
3- Scientific Writing Rules
4- Research Protocol
5- Referencing Using Mendeley software
6- Scientific Publication
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
Â
Contact us if you are interested:
Email / Skype : kefaya1771@gmail.com
Threema: PXHY5PDH
New BATCH Ku !!! MUCH IN DEMAND FAST SALE EVERY BATCH HAPPY GOOD EFFECT BIG BATCH !
Contact me on Threema or skype to start big business!!
Hot-sale products:
NEW HOT EUTYLONE WHITE CRYSTAL!!
5cl-adba precursor (semi finished )
5cl-adba raw materials
ADBB precursor (semi finished )
ADBB raw materials
APVP powder
5fadb/4f-adb
Jwh018 / Jwh210
Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
Flubrotizolam CAS: 57801-95-3
Metonitazene CAS: 14680-51-4
Payment terms: Western Union,MoneyGram,Bitcoin or USDT.
Deliver Time: Usually 7-15days
Shipping method: FedEx, TNT, DHL,UPS etc.Our deliveries are 100% safe, fast, reliable and discreet.
Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Â
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
Itâs work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganongâs Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Â
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? â The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
Â
RESULTS: Overall life span (LS) was 2252.1Âą1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years â 64.8%, 20 years â 42.5%. 513 LCP lived more than 5 years (LS=3124.6Âą1525.6 days), 148 LCP â more than 10 years (LS=5054.4Âą1504.1 days).199 LCP died because of LC (LS=562.7Âą374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0âN12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0âN12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowmanâs Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2â3 criteria; moderate AUD: 4â5 criteria; severe AUD: 6â11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Tom Selleck Health: A Comprehensive Look at the Iconic Actorâs Wellness Journeygreendigital
Â
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on:Â Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Â
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Report Back from SGO 2024: Whatâs the Latest in Cervical Cancer?bkling
Â
Are you curious about whatâs new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Womenâs Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Report Back from SGO 2024: Whatâs the Latest in Cervical Cancer?
Â
Introduction to meta-analysis (1612_MA_workshop)
1. Meta-analysis Workshop
From ZERO to HERO
Ahmed Negida
MBBCh candidate, Fifth Year Student
School of Medicine, Zagazig University, Egypt
2. Learning Objectives
⢠Introduction to descriptive and inferential statistics.
⢠Concept of meta-analysis
⢠Meta-analysis software
⢠Meta-analysis models
⢠Assessment of heterogeneity
⢠Assessment of publication bias
3. What is new in this workshop?
⢠Overview of different meta-analysis softwares
⢠Meta-analysis functions on MS Excel
⢠Quality effects meta-analysis model
⢠Q index as a safe-guards score
⢠Inverse variance heterogeneity model
⢠DOI plot and LFK index for assessment of publication bias
⢠Overview of the concept of indirect comparison of three-
treatment network using the âsingle closed loopâ method.
4. Important Terms
⢠Effect estimate
⢠Effect size
⢠Mean difference
⢠Standardized mean difference
⢠Prospective study
⢠Retrospective study
⢠Clinical Trial
⢠Randomized Controlled trial
5. Combining Effect Estimates
The drug (x) is being investigated for the treatment of insomnia.
Multiple clinical trials have evaluated the efficacy of drug (x).
Sleeping hours (h): Improvement = Post - Pre
There are 10 studies reporting the improvement in sleeping
duration with drug (x) in patients with insomnia. How can you
combine the results of these studies in one single combined
effect estimate?
7. Using the mean average to summarize effect
estimates is not correct!
The mean average assumes that all studies have the same power
(weight) to influence the final effect estimate. This is not correct
because studies do not have the same power and are not equal in
sample size or population distribution.
Why?
8. Concept ofmeta-analysis
A meta-analysis is a statistical
analysis that combines the
results of multiple scientific
studies.
The idea of meta-analysis is to
pool the weighted average of
studies/subgroups to give one
single effect estimate. Pooled Effect Estimate
Study
3
Study
1
Study
2
10. Why can not werely onsingle high-quality studies?
Under the most rigorous study design conditions, a well-planned single
study, even if prospective and randomized, rarely provides definitive
results, and primary studies tend to overestimate treatment effects.
A recent study reported that 32% of a set of studies with at least 1,000
citations were either contradicted by or reported stronger effects than
subsequent studies (Ioannidis, 2005).
Ioannidis JPA. Why Most Published Research Findings Are False. PLoS Medicine.
2005;2(8):e124. doi:10.1371/journal.pmed.0020124.
11. Advantages of meta-analysis
- Larger power (sample size)
- Reproducible (systematic review protocol)
- A small but clinically significant effect size might be
apparent in meta-analysis
12. Disadvantages of Meta-analysis
- Complicated statistical analysis
- Heterogeneity among studies
- Difference in outcome reporting