The document discusses key aspects of critically appraising research articles, including validity, study design, and statistical analysis. It provides 10 questions researchers should ask when evaluating a study, such as whether the study question is relevant, the design is appropriate, and statistical analyses were performed correctly. Additionally, it discusses the importance of addressing biases, adhering to original protocols, testing stated hypotheses, and identifying potential conflicts of interest. The questions are meant to help researchers properly assess research articles, especially those related to choosing diagnostic tests, selecting treatments, and making prognoses.

1. Critical Appraisal

2. Validity
01

3. Validity
● Results of a study are valid when the observed or estimated
parameter is the same as the true/actual value.
● The term bias refers to a systematic error in the study relating
to its design, data collection methods, or data analysis.
● Biases in epidemiological/patient-based studies fall into 3
categories: selection bias, information bias, and confounding
bias
● Criteria that are helpful for evaluating data include the study
design and the type of question being addressed (diagnosis,
treatment, prognosis, or harm).

4. Validity
● we will focus on appraisal of the literature based on the
primary clinical activities with which we are engaged in
clinical practice:
○ 1) choosing and interpreting diagnostic tests;
○ 2) selecting treatments/interventions; and,
○ 3) making prognoses.

5. Validity
Apakah uji diagnostic ini valid?
● Apakah uji diagnostik dibandingkan dengan baku emas yang
benar?
● Apakah pemeriksaan uji dan baku emas dilakukan secara
independen?
● Apakah uji diagnostik dilakukan terhadap spektrum pasien
seperti dalam praktik sehari hari ?
● Apakah pemeriksaan baku emas dilakukan kepada seluruh
subyek tanpa melihat hasil uji diagnostik?

6. How to read
an article?

7. TYPES OF SCHOLARLY ARTICLES
● Not every article in a scholarly, peer-reviewed journal is a
research article. There are several other types you may
encounter:
○ News, book reviews, opinion/editorials, letters to the
editor
○ Theoretical articles, relating to abstract principles – do not
contain original research
○ Review articles – summaries of the current research in a
field, but not considered to be research articles
themselves

8. WHAT IS A RESEARCH ARTICLE?
● A research article reports on the results of a study or
experiment. It is written by the person or people who did the
research. It is new, original work that has not been done
before.
● Look for these words in the title and abstract:
• Study
• Research
• Measure
• Subjects
• Data Effects
• Survey
• Statistical

9. THE ABSTRACT
● The abstract is a summary of the article.
● The abstract will give you enough information to determine
whether you want to use this article as a source.

10. THE LITERATURE REVIEW
● It gives the reader a summary of other research findings and
the current state of understanding of the topic, including areas
of incomplete data and questions that remain.

11. THE RESEARCH QUESTION
● The authors explain their hypothesis – the question they were
trying to answer with the study they have done.
● They should be doing something new, not simply copying what
someone else has already done.
● The authors may predict what they think they will find, and will
test their hypothesis to see if it is true.

12. MATERIALS AND METHODS I
● This section gives the details of the experiment:
○ How it was conducted
○ What techniques were used
○ What subjects were studied
○ How many people, animals or cells were included in the
study
○ The type of study

13. RESULTS
● This section presents the study’s findings, often using graphs
and statistical tables to illustrate.
● You will see statistical terms such as:
○ Mean – the average value of the responses
○ Standard deviation – how the variables are distributed
around the mean. A larger number means the responses
are more spread out: they deviate more from the mean.
○ P-value – a measure of how trustworthy the results are. A
pvalue will tell you whether the results are considered
statistically significant. When p < .05, it means there is a
95% chance that the differences in the study groups were
due to the manipulations of the study, and not due to
chance.

14. Diagnostic
02

15. Overview
Diagnose is a verb that means to:
● Identify
● Determine
● Distinguish
● Pinpoint
● Recognize characteristic that are individual peculiar and
proper

16. Characteristic of diagnostic test
● It must provide series of scores, each representing
performance in specific skill
● The respective skill must be carried to the over all
performance being evaluated such as reading achievement or
arithmetic achievement
● The sub test used to access each of these skills must
represent a valid measure
● Each subset must have high reliability
● The correlation among subset must be low

17. Preperation

18. DIAGNOSIS WORKSHEET
Apakah uji diagnostic ini valid ?
● Apakah uji diagnostik dibandingkan dengan baku emas yang
benar?
● Apakah pemeriksaan uji dan baku emas dilakukan secara
independen?
● Apakah uji diagnostik dilakukan terhadap spektrum pasien
seperti dalam praktik sehari hari ?
● Apakah pemeriksaan baku emas dilakukan kepada seluruh
subyek tanpa melihat hasil uji diagnostik?

19. DIAGNOSIS WORKSHEET
Apakah uji diagnostik ini penting ? Ya
● Sensitivitas : ?
● Spesifisitas :?
● NPV :?
● PPV :?

20. SAMPLE CALCULATIONS

21. DIAGNOSIS WORKSHEET
● Sensitivity = a/(a+c) = 731/809 = 90%
● Specificity = d/(b+d) = 1500/1770 = 85%
● Likelihood ratio for a positive test result = LR+ = sens/(1-spec)
= 90%/15% = 6
● Likelihood ratio for a negative test result = LR - = (1-sens)/spec
= 10%/85% = 0.12
● Positive Predictive Value = a/(a+b) = 731/1001 = 73%
● Negative Predictive Value = d/(c+d) = 1500/1578 = 95%
● Pre-test probability (prevalence) = (a+c)/(a+b+c+d) = 809/2579
= 32%
● Pre-test odds = prevalence/(1-prevalence) = 31%/69% = 0.45

22. DIAGNOSIS WORKSHEET
Dapatkah kita menerapkan hasil study pada pasien kita?

23. The Role of Diagnostic Tests
Diagnostic tests are used routinely in clinical practice. They can
be non-specific (complete blood count) and specific (Anti-CCP for
rheumatoid arthritis). Diagnostic tests are utilised for three key
reasons:
● Identification
Upon evaluating a patient, including a physical exam and
reviewal of symptoms, a clinician will order diagnostic tests to
confirm a suspected condition or to exclude conditions.
● Monitoring
Following a diagnosis, further diagnostic tests can be
requested to determine if the treatment is working effectively

24. The Role of Diagnostic Tests
● Prognosis
Diagnostic testing can aid a doctor in reviewing the
progression of disease and predict how long one will live.

25. RESEARCH
03

26. Why to do research
● Add to scientific knowledge.
● Improve the medical and health practice.
● Benefit the patients and community.
● Study new phenomenon for establishing the facts.
● Help in planning the medical and health programs.
● Support managerial aspects of health development.
● Improve diagnostic techniques by newer, cheaper and
accurate tests.
● Help in effective patient care management.

27. Type of research

28. INTRODUCTION
● Population is a large group of study subjects (human, animals,
tissues, blood specimens, medical records, etc) with defined
characteristics [“Population is a group of study subjects defined
by the researcher as population”]
● Sample is a subset of population which will be directly
investigated. Sample should be (or assumed to be)
representative to the population; otherwise all statistical
analyses will be invalid
● All investigations are always performed in the sample, and the
results will be applied to the population

29. Avoid using ambiguous terms
● Sample population
● Sampled population
● Populasi sampel
● Study population ~ sample

30. Sample is assumed to be representative to the population.
In research: measurements are always done in the sample,
the results will be applied to population
P P

31. P S
Investigation
S P
S
Sampling
Inference
Results

32. Target population Accessible
population
Intended
Sample
Actual
study subjects

33. ● Target population = domain = population in which the results
of the study will be applied. In clinical research it is usually
characterized by demographic & clinical characteristics; e.g.
normal infants, teens with epilepsy, post-menopausal women
with osteoporosis.
● Accessible population = subset of target population which can
be accessed by the investigator. Frame: time & place. Example:
teens with epilepsy in RSCM, 2000-2005; women with
osteoporosis, 2002 RSGS
● Intended sample = subjects who meet eligibility criteria and
selected to be included in the study
● Actual study subjects = subjects who actually completed the
participation in the study

34. Accessible
population
(+ time,
place)
Usually based on practical
purposes
Appropriate
sampling
technique
[Non-response, drop outs,
withdrawals, loss to follow-up]
Target population
(demographic, clinical)
Intended
Sample
[Subjects selected
for study]
Actual
study
subjects
Subjects
completed
the study
Dikutip dari slide Prof Dr.dr. Sudidgo Sastroasmoro, SpA(K) ; s_sudigdo@yahoo.com/2014

35. SAMPLING PROCESS
STEP

36. SAMPLING TECHNIQUES

37. PROBABILITY
SAMPLING
01

38. PROBABILITY SAMPLING
● Probability sampling means that every item in the population
has an equal chance of being included in sample.
● Salah satu cara untuk melakukan pengambilan sampel secara
acak adalah jika peneliti membuat kerangka pengambilan
sampel terlebih dahulu dan kemudian menggunakan program
komputer penghasil angka acak untuk mengambil sampel dari
kerangka pengambilan sampel. (Zikmund, 2002).
● Probabilitas atau pengambilan sampel acak mempunyai
kebebasan paling besar dari bias namun mungkin mewakili
sampel yang paling mahal dalam hal waktu dan energi untuk
tingkat kesalahan pengambilan sampel tertentu.

39. PROBABILITY SAMPLING
• every case of the population has an equal probability of inclusion in
sample.
• Disadvantages :
• A complete frame ( a list of all units in the whole population) is
needed
• In some studies, such as surveys by personal interviews, the costs of
obtaining the sample can be high if the units are geographically
widely scattered;
Simple random sampling

40. PROBABILITY SAMPLING
• Systematic sampling is where every case after a random start is selected.
• The advantage : its simplicity
• How to do it :
• Sampling frame is needed*
• Calculate sample size
• Divide number of population with number of sample size > you got nth
(kelipatan)
• Start with the number randomized, than pick based on the nth you got
Systematic sampling

41. PROBABILITY SAMPLING
• This method is a modification of the simple random sampling
• Sampling frame is needed
• the whole population is divided into homogeneous strata or subgroups
according a demographic factor (e.g. gender, age, religion, socio-economic
level, education, or diagnosis etc.).
• Then, the researchers select draw a random sample from the different
strata
• Used when population is heterogen
Stratified random sampling

42. PROBABILITY SAMPLING
• How to do it
• Simple Stratified Random Sampling :
• Divide sample size with the strata
• Proportional Stratified Random Sampling
• Divide sample size based on the proportion of population in each
strata
Stratified random sampling

43. Example :
Simple Stratified Random Sampling

44. Example :
Proportional Stratified Random
Sampling

45. PROBABILITY SAMPLING
• It is used when creating a sampling frame is nearly impossible due to the
large size of the population.
• Cluster sampling is where the whole population is divided into clusters or
groups
• Subsequently, a random sample is taken from these clusters, all of which
are used in the final sample (Wilson, 2010)
• In this method, the population is divided by geographic location into
clusters
CLUSTER SAMPLING

46. PROBABILITY SAMPLING
How to do it :
• Choose cluster grouping for sampling frame, such as type of company or
geographical region
• Number each of the clusters
• Select sample using random sampling
CLUSTER SAMPLING

47. Simple one stage Cluster Sampling
SINGLE CLUSTER
RW RW RW
JAKARTA

48. Kelayakan
04

49. ▪ Selection and critical appraisal of
research literature
▪ 10 QUESTIONSTO ASK WHEN
CRITICALLY APPRAISING A
RESEARCH ARTICLE:
1 Is the study question relevant?
2 Does the study add anything new?
3What type of research question is
being asked?
4Was the study design appropriate
for the research question?

50. Introduction
You can give a brief description of the topic you want to talk about
here. For example, if you want to talk about Mercury, you can say that
it’s the smallest planet in the entire Solar System

51. TEN QUESTIONS TO ASK WHEN CRITICALLY
APPRAISING A RESEARCH ARTICLE: Cont.
5. Did the study methods address the most important sources of
bias?
6. Was the study performed according to the original protocol?
7. Does the study test a stated hypothesis?
8. Were the statistical analyses performed correctly?
9. Do the data justify the conclusions?
10. Are there any conflicts of interest?

52. Daftar Pustaka
1. Taherdoost, H. Sampling Methods in Research Methodology; How to
Choose a Sampling Technique for Research. International Journal of
Academic Research in Management (IJARM) Vol. 5, No. 2, 2016, Page:
18-27, ISSN: 2296-1747
2. © Helvetic Editions LTD, Switzerland
3. Elfil, M. Negida, A. Sampling methods in Clinical Research; an
Educational Review . Emergency. 2017; 5 (1): e52
4. Guest Editorials. Sampling Methods in Research Design. Headache.
American Headache Society.2019. Wiley Periodicals, Inc Publishers.
5. Sastroasmoro, S. Ismael,S. Dasar Dasar Metodologi Penelitian
Klinis.ed.4.Sagung Seto.2011