dimitrios g. goulis professorof reproductiveendocrinology...

Critical appraisalDimitrios G. Goulis

Professor of Reproductive EndocrinologyAristotle University of Thessaloniki

Unit of Reproductive EndocrinologyFirst Department of Obstetrics and GynecologyAristotle University of Thessaloniki

Conflicts of interest

• During the last three years, I have received research, educational and travel grants from scientific societies and pharmaceutical companies.

• I am currently or have been:• President, Hellenic Society of Andrology (2013 ‐ 2017)• Secretary General, European Academy of Andrology (2014 ‐ 2018)• Secretary General, European Menopause and Andropause Society (2017 ‐ 2019)• Director, Training centre European Academy of Andrology (2013 ‐ 2019)• Director, MSc in “Research Methodology in Medicine and Health Sciences” (2018 ‐ 2021)• Member of the Executive Board, Hellenic Society of Endocrinology (2011 ‐ 2013)• Member of the Executive Board, Hellenic Society of Climacteric and Menopause (2013 ‐ 2019)• Associate Editor, Human Reproduction (2009 ‐ 2013), Associate Editor, Hormones (2012 ‐ 2019)• Μember of the Editorial Board, Andrology (2012 ‐ 2019), Μember of the Editorial Board, Maturitas (2015 ‐ 2019)• Μember of the Editorial Board, Journal of Endocrinological Investigation (2014 ‐ 2019)• Associate Editor, Human Reproduction Open (2017 ‐ 2019) • Associate Editor, Human Andrology (2017 ‐ 2019)

• None of these can be considered as a conflict of interest for today’s lecture.

Aim

• Discuss the basic principles of critical appraisal

• Be practical

Types of question

Validity vs. Importance

Validity (εγκυρότητα) Importance (σημαντικότητα)

Diagnostic accuracy studies

Issues to be discussed

Are the results of the study valid?

P

Is ferritin equally good to bone marrow biopsy for the diagnosis of iron deficiency anemia?

(I) T

O

C

What is the role of ferritin in iron deficiency anemia?

Patient with iron deficiency

Ferritin

What are the results?

Clinical case

• Patient with anemia • Clinical examination• Possibility of iron deficiency anemia: 50%

• Serum ferritin• Literature search• Comparison to bone marrow biopsy valid

• Serum ferritin: 60 mmol/l

Table 2 x 2

Disease

present absent

Testpositive a b a + b

negative c d c + d

a + c b + d

Indices

1. Sensitivity a / (a+c)

2. Specificity d / (b+d)

3. PPV a / (a+b)

4. NPV d / (c+d)

5. LR (+) sensitivity / (1‐specificity)

6. LR (‐) (1‐sensitivity) / specificity

Disease

present absent

Testpositive a b a + b

negative c d c + d

a + c b + d

Table 2 x 2

Iron deficiency

present absent

Ferritin< 65 mmol/l 731 270 1001

65 mmol/l 78 1500 1578

809 1770 2579

Indices

1. Sensitivity 731 / 809 = 90%

2. Specificity 1500 / 1770 = 85%

3. PPV 731 / 1001 = 73%

4. NPV 1500 / 1578 = 95%

5. LR (+) 90% / (1‐85%) = 6

6. LR (‐) (1‐90%) / 85% = 0.1

Iron deficiency

present absent

Ferritin< 65 mmol/l 731 270 1001

65 mmol/l 78 1500 1578

809 1770 2579

Will the results help locally?

Randomized controlled trials

In patients with diabetes mellitus type 2is four‐injection regimen superior than two‐injection regimen

for the prevention of diabetic neuropathy?

PI

O

C

Randomization

Intention‐to‐treat‐analysis

Intention‐to‐treat analysis

Blinding

Randomization

What are the results?

Treatment study

• In patients with diabetes mellitus type 2 is four‐injection regimen (“intensive”) superior than two‐injection regimen (“standard”) for the prevention of diabetic neuropathy?

Clinical case

• DCCT – neuropathy

• Standard therapy 9.6%• CER: control event rate

• Intensive therapy 2.8%• EER: experimental event rate

Relative Risk Reduction (RRR)

• (CER ‐ EER) / CER• (9.6% ‐ 2.8%) / 9.6% = 71%

• The risk in general population is not taken under consideration

• Distinction between high and low risk is not possible

Absolute Risk Reduction (ARR)

• CER ‐ EER• 9.6% ‐ 2.8% = 6.8%

• The risk in general population is taken under consideration

• Distinction between high and low risk is possible

Number Needed to Treat

• 1 / ARR• 1 / 6.8% = 15

• Number of patients that have to be treated in order to prevent an additional negative event

RRR, ARR and NNT

Numbers Needed to Treat

Will the results help locally?

Aim

• Discuss the basic principles of critical appraisal

• Be practical

Diagnostic accuracy studies

Randomized controlled trials

PhD candidates and Post‐doc researchersC. Tsametis (endocrinologist)P. Poulakos (endocrinologist)E. Kintiraki (endocrinologist)G. Mintziori (endocrinologist)P. Anagnostis (endocrinologist)P. Iliadou (endocrinologist)C. Dimopoulou (endocrinologist)I. Litsas (endocrinologist)I. Koutsogiannis (urologist)A. Kouthouris (urologist)G. Kanakis (endocrinologist)A. Mousiolis (endocrinologist)S. Paschou (endocrinologist)E. Billa (endocrinologist)K. Papadimitriou (endocrinologist)V. Harizopoulou (midwife)E. Tsirou (endocrinologist, dietician)E. Taousani (midwife)D. Savvaki (physical education)M. Grammatikopoulou (dietician)N. Athanasiadou (dietician)M. Grammatikopoulou (dietician)I. Koptsi (psychologist)

Unit of Reproductive EndocrinologyProfessor D.G. GoulisProfessor emeritus J. Papadimas

Departments of Physical EducationProfessor emeritus S. TokmakidisAssociate professor K. DiplaAssociate professor A. Zafiridis

First Department of Obstetrics and GynecologyAristotle University of Thessaloniki

Professor G.F. Grimbizis

Unit of Human ReproductionProfessor E.M. Kolibianakis

dimitrios g. goulis professorof reproductiveendocrinology...

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