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Research Design & EBM. Ravi Kant MS, DNB, FAMS, FRCS (Edin), FRCS (Glasg), FRCS (Engl.), FRCS (Irel.), FACS, FICS, FAIS Professor of Surgery. Science. Intelligent Hypothesis Experiments & analysis of results prove that hypothesis is correct. Replicable universally= Most Important.

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slide1

Research Design &EBM

Ravi Kant

MS, DNB, FAMS, FRCS (Edin), FRCS (Glasg), FRCS (Engl.), FRCS (Irel.), FACS, FICS, FAIS

Professor of Surgery

science
Science
  • Intelligent Hypothesis
  • Experiments & analysis of results prove that hypothesis is correct.
  • Replicable universally= Most Important
evidence based medicine what it is and what it isn t
Evidence based medicine: what it is and what it isn\'t
  • Integrating individual clinical expertise and the best external evidence
  • BMJ 1996;312:71-72 (13 January) 
  • Editorial
observational study
Observational study
  • Evaluating results of condition or treatment in a defined population
retrospective
Retrospective:

analyzing past events

prospective
Prospective:
  • collecting data contemporaneously
case control
Case-control
  • Series of patients with a particular disease or condition contrasted with matched control patients
cross sectional
Cross-sectional

Measurements mode on a single occasion, not looking at whole population but selecting small similar group & expanding results

longitudinal
Longitudinal
  • Measurements are taken over a period of time, not looking at whole population but selecting small similar group & expanding results
experimental
Experimental
  • Two or more treatments are compared. Allocation to treatment groups is under the control of the researcher
randomized
Randomized
  • Two randomly allocated treatments
prospective randomized controlled
Prospective Randomized controlled

Includes control group with no treatment

= GOLD STANDARD

confidence interval
Confidence Interval
  • To p or not to p
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RR
  • Relative Risk
systemic review
Systemic Review
  • reliable
  • systematic
  • predefined, explicit methodology
  • minimize bias
  • Systemic review+ Statistics= meta-analysis
levels of evidence
Levels of evidence
  • 1= Meta-analyses of Prospective Double blind randomized controlled trials
  • 2=Prospective Randomized Controlled study/ Meta-analyses of retrospective studies
  • 3= Case series/ Cohort study
  • 4= Case report/ observational
  • 5= Expert opinion
evidence grade i
Evidence grade: I
  • I (High): the described effect is plausible, precisely quantified and not vulnerable to bias
evidence grade i1
Evidence grade: I
  • II (Intermediate): the described effect is plausible but is not quantified precisely or may be vulnerable to bias
evidence grade iii
Evidence grade : III
  • III (Low): concerns about plausibility or vulnerability to bias severely limit the value of the effect being described and quantified
strength of recommendation definition a
Strength of recommendation Definition A
  • A=Recommendation based on consistent and good quality patient-oriented evidence
strength of recommendation definition b
Strength of recommendation Definition B
  • B=Recommendation based on inconsistent or limited quality patient-oriented evidence
strength of recommendation definition c
Strength of recommendation Definition C
  • C=Recommendation based on consensus, usual practice, opinion, disease-oriented evidence or case series for studies of diagnosis, treatment, prevention, or screening.
recommendation grade a
Recommendation grade: A
  • A (Recommendation): there is robust evidence to recommend a pattern of care
recommendation grade b
Recommendation grade : B
  • B (Provisional recommendation): on balance of evidence, a pattern of care is recommended with caution
recommendation grade c
Recommendation grade : C
  • C (Consensus opinion): evidence being inadequate, a pattern of care is recommended by consensus
us government agency for health care policy and research ahcpr a
US Government Agency for Health Care Policy and Research (AHCPR):A
  • A: requires at least one randomized controlled trial as part of the body of evidence.
us government agency for health care policy and research ahcpr b
US Government Agency for Health Care Policy and Research (AHCPR):B
  • B: requires availability of well-conducted clinical studies but no randomized controlled trials in the body of evidence.
us government agency for health care policy and research ahcpr c
US Government Agency for Health Care Policy and Research (AHCPR):C
  • C: requires evidence from expert committee reports or opinions and/ or clinical experience of respected authorities. Indicates absence of directly applicable studies of good quality
grading of evidence
Grading of evidence
  • Ia: Systematic review or meta-analysis of randomized controlled trials
  • Ib: at least one randomized controlled trial
  • IIa: at least one well-designed controlled study without randomization
  • IIb: at least one well-designed quasi-experimental study, such as a cohort study
  • III: well-designed non-experimental descriptive studies, such as comparative studies, correlation studies, case–control studies and case series
  • IV: expert committee reports, opinions and/or clinical experience of respected authorities
grading of recommendations
Grading of recommendations
  • A: based on hierarchy I evidence
  • B: based on hierarchy II evidence or extrapolated from hierarchy I evidence
  • C: based on hierarchy III evidence or extrapolated from hierarchy I or II evidence
  • D: directly based on hierarchy IV evidence or extrapolated from hierarchy I, II or III evidence
research can be quantitative
Research can be Quantitative:

A medical condition is analyzed systematically using hard, objective end point such as death or amputation.

research can be qualitative
Research can be Qualitative

Data come from patient narratives, and the psychosocial impact of the disease and its treatment are analyzed, for example narratives of breast cancer.

project design include
Project design include:

Sample size.

Eliminating bias.

Study protocol.

Ethics.

sample size
Sample size

An incorrect sample size is probably the most frequent reason for research to be invalid.

Never forget that more patients will need to be randomized than the final sample size to take into account patients who die, drop out or are lost to follow up.

sample size1
Sample size
  • nX[r(100-r)+s(100-s)]/(r-s)2
type i error
Type I error
  • Benefit is perceived when really there is none (false positive)
type ii error
Type II error
  • Benefit is missed because the study has small numbers (false negative)
eliminating bias single blind
Eliminating bias: Single blind

The observers or recorders who do not know which treatment has been used.

eliminating bias double blind
Eliminating bias: Double blind

Neither patient nor researcher is aware of which therapy has been used until after study has finished, & these are the best randomized studies.

the cochrane collaboration
The Cochrane Collaboration
  • Best evidence
  • an international not-for-profit and independent organization,
  • It produces and disseminates systematic reviews of healthcare interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions.
  • The Cochrane Collaboration was founded in 1993 and named after the British epidemiologist, Archie Cochrane.
current reliable evidence based medicine resources for the busy clinician 1
Current reliable evidence-based medicine resources for the busy clinician -1
  • American College of Physicians Journal Club http://www.acpj.org
  • American Family Physician http://www.aafp.org/afp
  • Bandolier http://www.rj2.ox.ac.uk/bandolie
  • Clinical Evidence http://www.clinicalevidence.com
current reliable evidence based medicine resources for the busy clinician 2
Current reliable evidence-based medicine resources for the busy clinician -2
  • Cochrane Database of Systematic Reviews http://www.cochrane.org/reviews/en/
  • Database of Abstracts of Reviews of Effects (DARE) http://www.york.ac.uk/inst/crd/crddatabases.htm
  • Dr. Alper\'s Useful Links http://www.myhq.com/public/a/l/alperDynaMed http://www.dynamicmedical.com
  • Family Practitioners Inquiries Network (FPIN) Clinical Inquiries http://www.fpin.org
  • FIRSTConsult http://www.firstconsult.comInfoPOEMs – The Clinical Awareness Systemhttp://www.infopoems.com
current reliable evidence based medicine resources for the busy clinician 3
Current reliable evidence-based medicine resources for the busy clinician -3
  • Institute for Clinical Systems Improvement (ISCI) http://www.icsi.org/knowledge
  • Journal of Family Practice http://www.jfponline.org
  • SUM Search http://sumsearch.uthscsa.edu
  • TRIP Database
  • http://www.tripdatabase.comUpToDate http://www.uptodate.com
current reliable evidence based medicine resources for the busy clinician 4
Current reliable evidence-based medicine resources for the busy clinician -4
  • US National Guideline Clearinghouse http://www.guidelines.gov
  • U.S. Preventive Services Task Force (USPSTF) Recommendations http://www.ahrq.gov/clinic/uspstfix.htm
current reliable evidence based medicine resources for the busy clinician 5
Current reliable evidence-based medicine resources for the busy clinician -5
  • Bandolier
    • Evidence based thinking about healthcare
  • Cochrane Library Database of Systematic Reviews
    • Full text systematic reviews of health care interventions, prepared by The Cochrane Collaboration.
  • The Database of Abstracts of Reviews of Effects (DARE)
    • Critical appraisal of systematic reviews published in the medical literature.
  • Health Technology Assessment Database (HTA)
    • Completed and on-going health technology assessments from around the world
  • NHS Economic Evaluation Database (NHS EED)
    • Reliable information about the costs as well as the effects of drugs, treatments and procedures, to inform decisions.
  • UK Database of Uncertainties about the Effects of Treatments
    • Publishes those patients\' and clinicians\' questions about the effects of treatments which cannot currently be answered reliably by referring to up-to-date systematic reviews of existing research.
web search 6
Web search-6
  • Clinical evidence.com
  • Cochrane.org
  • Consolidated Standards of Reporting trials= consort-statement.htm
  • National Institute for Health & Clinical excellence (NICE.org.uk
  • Scottish Intercollegiate Guideline Network (SIGN) www.sign.ac.uk
web based evidence based medicine courses 1
Web-based evidence-based medicine courses-1

•    http://www.poems.msu.edu/infomastery: •    http://www.hsl.unc.edu/services/tutorials/ebm/welcome.htm: •    http://www.uic.edu/depts/lib/lhsp/resources/ebm.shtml:.•    http://library.ncahec.net/ebm/pages/index.htm:

web based evidence based medicine courses 2
Web-based evidence-based medicine courses-2
  • http://www.urmc.rochester.edu/hslt/miner/resources/evidence_based/index.cfm:
  • http://library.downstate.edu/EBM2/contents.htm:
  • http://www.healthsystem.virginia.edu/internet/library/collections/ebm/index.cfm:
  • http://www.cebm.net/:
  • http://www.sheffield.ac.uk/∼scharr/ir/netting/:
poems
POEMS
  • Journals with highest frequency of articles that contain patient oriented evidence that matters (POEMs)
impact factor
Impact factor
  • = average number of citations to those papers that were published during the two preceding years.
impact factor1
Impact factor

For example, the 2008 impact factor of a journal would be calculated as follows:

  • A = the number of times articles published in 2006 and 2007 were cited by indexed journals during 2008
  • B = the total number of "citable items" published in 2006 and 2007. ("Citable items" are usually articles, reviews, proceedings, or notes; not editorials or Letters-to-the-Editor.)
  • 2008 impact factor = A/B
high impact journals those cited most frequently by others
High-impact journals (those cited most frequently by others)
  • Annals of Internal Medicine
  • British Medical Journal
  • Journal of the American Medical Association
  • Lancet
  • New England Journal of Medicine
preclinical studies
Preclinical studies
  • Even animal studies need ethical clearance in Europe
  •  Efficacy, toxicity and pharmacokinetic
  • data
phase 0
Phase 0
  • Human microdosing
  • Distinctive features of Phase 0 trials include the administration of single subtherapeutic doses of the study drug to a small number of subjects (10 to 15) to gather preliminary data on the agent\'s pharmacokinetics (how the body processes the drug) and pharmacodynamics (how the drug works in the body)
phase 1 trial
Phase 1 trial
  • Dose escalation =Dose ranging
  • Pharmacovigilance
slide73
SAD
    • Single Ascending Dose studies
  • MAD
    • Multiple Ascending Dose studies
  • Crossover study
    • A short trial designed to investigate any differences in absorption of the drug by the body, caused by eating before the drug is given. These studies are usually run as a crossover study, with volunteers being given two identical doses of the drug on different occasions; one while fasted, and one after being fed.
phase ii
Phase II
  • Larger group
  • Phase IIA is specifically designed to assess dosing requirements (how much drug should be given).
  • Phase IIB is specifically designed to study efficacy (how well the drug works at the prescribed dose(s)).
phase ii1
Phase II
  • Toxixity & efficacy defines go ahead or not
phase iii
Phase III
  • Phase III studies are randomized controlled multicenter trials on large patient groups (300–3,000 or more depending upon the disease/medical condition studied)
phase iv
Phase IV
  • Phase IV trial is also known as Post Marketing Surveillance Trial
  • = Pharmacovigilance
research design
Research Design
  • It\'s always easier to explain design notation through examples than it is to describe it in words. The figure shows the design notation for apretest-posttest (or before-after) treatment versus comparison group randomized 
experimental study steps
Experimental study- steps
  • Animal model
  • Induce tumor by viral inoculation
  • Treat tumor by various laser wavelength
  • Correct wavelength applied in incurable humans
  • Regular Clinical approach
pilot study
Pilot study
  • Somprakas Basu, Bina Ravi & Ravi Kant: Interstitial laser Hyperthermia, a New Method in the Management of Fibroadenoma of the Breast: A Pilot Study. Lasers in Surgery and Medicine, 1999: Vol. 25: p 148-152.
interstitial laser hyperthermia
Interstitial Laser Hyperthermia
  • For solid tumors of-
  • Liver
  • Pancreas
  • Lymph nodes
ilh pancreas
ILH & Pancreas
  • Kant Ravi, Masters A, Lees WR, Bown SG: Interstitial Laser Hyperthermia in Human pancreas tumors: GUT, supplement 1992. Vol. 33 No 1 W69, p S18.
lab studies need infrastructure
Lab studies► need infrastructure

Hedau S, Jain N, Husain SA, Mandal AK, Ray G, Shahid M, Kant R, Gupta V, Shukla NK, Deo SS, & Das BC. Novel germ line mutations in breast cancer susceptibility genes BRCA1, BRCA2 and p53 gene in breast cancer patients from India. Breast Cancer Research Treat 2004 Nov, 88(2):177-86.

the liver the drains do not offer any benefit after elective liver resections
The Liver: The drains do not offer any benefit after elective liver resections.
  • Marcello Spampinato Hassan Elberm & Colin D Johnson in Recent Advances in Surgery # 31, by Irving Taylor & Colin Johnson, The Royal Society of Medicine Press,  2008 page 189-
  • Gurusamy KS, Samraj K, Davidson BR. Routine abdominal drainage for uncomplicated liver resections.  Cochrane Database Systemic Rev 2007; CD006232
slide94
GB
  • The Gall Bladder: The drains do not offer any benefit after routine uncomplicated laparoscopic cholecystectomy.
    • Marcello Spampinato Hassan Elberm & Colin D Johnson in Recent Advances in Surgery # 31, by Irving Taylor & Colin Johnson, The Royal Society of Medicine Press,  2008 page 196-
    • Gurusamy KS, Samraj K, Mullerat P et al. Routine abdominal drainage for uncomplicated laparoscopic cholecystectomy.  Cochrane Database Systemic Rev 2007; CD006004
the thyroid no drain is required following thyroidectomy
The Thyroid: No drain is required following thyroidectomy.
  • Khanna J, Mohil RS, Chintamani, Bhatnagar D, Mittal MK, Sahoo M, Mehrotra M. Is the routine drainage after surgery for thyroid necessary? A prospective randomized clinical study [ISRCTN63623153]. BMC Surg. 2005 May 19; 5:11.
  • Suslu N, Vural S, Oncel M, Demirca B, Gezen FC, Tuzun B, Erginel T, Dalkilic G. Is the insertion of drains after uncomplicated thyroid surgery always necessary? Surg Today. 2006; 36(3):215-8.
  • Lee SW, Choi EC, Lee YM et al. Is lack of placement of drains after thyroidectomy with central neck dissections safe? A prospective randomized study. Laryngoscope 2006;116:1632-1635
the breast no drain is required after conservation surgery for breast cancer
The Breast: No drain is required after conservation surgery for breast cancer
  • Stojkovic C, Smeulders MJ, Van der Horst CM. Wound drainage after plastic and reconstructive surgery of the breast (Protocol). Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD007258. DOI: 10.1002/14651858.CD007258.
slide97
Rectal Surgery: The pelvic drainage after rectal surgery adds no benefit.
    • Urbach DR, Kennedy ED, Cohen MM. Colon and rectal anastomosis donot require routine drainage: a systemic review and meta-analysis. Ann Surg 1999; 229:174-180.
slide98
Incision by electrocautery heal as well as incision by knife. No difference in either postoperative results or in cosmesis.
    • Kears SR, Connolly EM, Mc Nally S, McNamara DA, Deasy J. Randomized clinical trial of diathermy versus scalpel incision in elective midline laparotomy.
    • Br J Surg 2001; 88:41-44. 
evidence based surgery
Evidence-Based surgery

Evidence-base study is a move to find out the best ways of managing patients using clinical evidence from collected studies.

Collecting published evidence together and analyzing it often requires review of multiple randomized trials.

These meta-analysis involve complex statistical analysis designed to interpret multiple findings and synthesize the results of multiple studies.

important advantages of evidence based medicine
Important advantages of evidence-based medicine
  • Has the potential to improve quality of patient care
  • Identifies and promotes practices that are proven scientifically to be effective
  • Identifies practices that are ineffective or harmful
  • Promotes critical thinking
  • Requires clinicians to be open-minded
  • Encourages researchers to focus on evidence and outcomes that are important to clinicians and patients
poems1
POEMS
  • patient-oriented evidence that matters (POEMs)
drains evidence
Drains & Evidence
  • Presented in your book as a chapter
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