critical appraisal

1. Group 9

2. • Puveraj Gunasekaran 130110132026
• Nor Adira Eliany Binti Alias 130110113053
• Michelle Ann Sheridan Daniel 130110132017
• Visalakshi Ramanathan 130110132042
• Muhammad Ikhlas Abdian Putra 130110130126
• Raka Ghufran Wibowo 130110130170
• Ahsani Rahma Rudibianti 130110130073
• Muhammad Nuur Fauzi 130110130049
• Renita Dewi Supiyana 130110130115
• Amalia Ahsani 130110130061
• Evi Anugrah Arumningsih 130110130074
• Fatimah Amalia 130110130140
• Nabila Nauli Asriputri 130110130155
• Jasmine Maulinda Utami 130110130195

3. Answerable question based on the scenario above
according to PICO scheme.
• Patients or Problems : Patients diagnosed with Ischemic
Stroke
• Intervention : Iron-Deficiency Anemia
• Comparison Intervention : Non Iron-Deficiency Anemia,
subarachnoid/intracerebral hemorrage
• Outcome : Ischemic Stroke; Association between prior
IDA and ischemic stroke

4. 1. Did the study address a clearly focused issue?
• Yes, definitely it had a focused issues high was the
colleration of ischemic stroke and its role in patients with
eventually has iron deficiency anaemia.

5. 2. Did the authors use an appropriate method to
answer their question?
Yes, because by using case control study, we can find the
association between a disease and other disease

6. 3. Were the cases recruited in an acceptable way?
No, because the sample of cases choose from subjects who had received
their first time diagnosis stroke (all type of stroke not specific ischemic
stroke)
- Are the cases defined precisely? Yes, the cases explain completely about sample
(amount, database sources, sex and age group, geographic region, medical co-
morbidity) but the cases not specific to ischemic stroke but also explain about other
cardiovascular disease
- Were the cases representative of a defined population (geographically and/or
temporally)? Yes, because the cases explain about the geographically region and
sufficient long time for took the sample (January 1 2013 to December 31 2011)
- Was there an established reliable system for selecting all the cases? Can’t tell
- Are they incident or prevalent? prevalence
- Is there something special about the cases? Can’t tell
- Is the time frame of the study relevant to the disease/exposure? Yes, because
very little is known about this cases (rare cases)
- Was there a sufficient number of cases selected? yes
- Was there a power calculation? Yes, calculation of odd ratio

7. 4. Were the controls selected in an acceptable
way?
Yes
The controls were selected from the LHID2000 of
Taiwan National Health Insurance (NHI). The
controls were randomly selected based on the
remaining subjects from those who hadn't had a
history of stroke since 1995. Then, the subjects
were randomly matched with sex in ratio of 3:1.
The index year was simply matched year in which
controls visited a physician. The controls selected
were three times more than cases.

8. • 5. Was the exposure accurately measured to minimise bias?
• Answer: Yes
• Reason:
• The article states that this study identified IDA cases based on ICD-
9-CM codes 280, 280.0, 280.1, 280.8 and 280.9. In order to increase
the validity of IDA diagnoses, this study only included cases that
have at least two diagnoses of IDA in their medical claims prior to
their index date as IDA cases.
• According to their clinical guidelines and health insurance regulations
under the Taiwan NHHI program, patients suspected to have IDA
might receive a diagnosis of unspecified anemia (ICD-9-CM code
285) in their first visit. However, to have a definite diagnosis of IDA
(ICD-9-CM code 280), the patient must be confirmed by receiving the
laboratory test (decreased serum iron and ferritin, increased TIBC).
• Therefore, we believe that the diagnosis of IDA remains fairly
reliable.

9. • 6. A. What confounding factors have the authors accounted for?
• confounding factors that mentioned by authors:
• 1) co-morbidity with other cardiovascular diseases
• 2) lack of medicine or treatment history from subject
• confounding factors that not yet mentioned by authors:
• 1) genetics
• 2) lifestyle
• 3) geographic factor(tinggal dimana dan exposure apa yg mungkin
terpapar)
• B. Have the authors taken account of the potential confounding
factors in the design and/or in their analysis?
• yes

10. Results showed that 3,685 study subjects (1.81%) had been
diagnosed with IDA prior to the index date; of those subjects,
1,268 (2.48%) were cases and 2,417 (1.58%) were controls
(p<0.001). Conditional logistic regression shows that the OR of
having previously received an IDA diagnosis among cases was
1.49 (95% CI: 1.39~1.60; p < 0.01) that of controls after
adjusting for monthly income, geographic region, hypertension,
diabetes, coronary heart disease, atrial fibrillation, heart failure,
hyperlipidemia, tobacco use disorder, and alcohol abuse/alcohol
dependency syndrome. Furthermore, the adjusted OR of prior
IDA for cases with ischemic stroke was found to be 1.45 (95%
CI: 1.34~1.58) compared to controls. However, we did not find
any significant relationship between IDA and
subarachnoid/intracerebral hemorrhage even adjusting for other
confounding factors (OR=1.17, 95% CI=0.97~1.40). There is a
significant association between prior IDA and ischemic stroke.

11. - The analysis is appropriate to the design, because the
analysis begin with matching for sex and age group, and
then look for cases, and then look for exposure. It’s the
characteristic of case control study, so, the appropriate to
the design
- The association between exposure and outcome (based
on the odds ratio) is strong. The OR > 1, it’s mean
exposure associated with higher odds of outcome.
- The results are adjusted for confounding. The potential
confounding factor slightly weakened the association.
- The OR doesn’t have big difference . Odd Ratio 1,49.
Adjusted Odds Ratio is 1,45.

12. • 8. How precise are the results?
• P value < 0,001
• -CI = 95 %
• -Author also adjust monthly income, geographic region, h
ypertension, diabetes, coronaty heart disease, atrial fibrill
ation, heart failure, hyperlipidemia, tobacco use disorder,
and alcohol abuse/alcohol dependency syndrome
• -all subject participate (case control study)

13. • 9. Do you believe the results?
• Yes, because there is a table to prove the results is true.

14. • 10. Can the result be applied to the local population?
• cant't tell, because form the table of demographic, there
is regional disribution in Taiwan itself, there are eastern,
central, southern, western, and the results are different.
It’s mean, geographical location has influence to
terhadap the result. But, it’s not decribed detailly, so that
sehinnga we can determine to say yes or no.

15. • 11. Do the results of this study fit with other available
evidence? Yes
• Because the conclusion states that there is a significant
association between prior IDA and ischemic stroke and
the results state that there is no significant relationship
between IDA and subarachnoid/intracerebral
hemorrhage. And the Odds Ratio > 1