1. Chronic Bronchitis

2. Emphysema

Please refer to this high yield table for more details

Summary of different variables and the expected findings with different diseases
FEV1/FVC ratio	Ventilatory Pattern	FEV1/FVC ratio	DLCO	TLC	Diagnosis
Normal	Normal	Normal	Decreased	normal	Primary  pulmonary hypertension
Decreased	Obstructive pattern	Decreased	Normal	Increased	Chronic bronchitis/ Asthma
Decreased	Obstructive pattern	Decreased	Decreased	Increased	Emphysema
Normal/ Increased	Restrictive pattern	Normal/ Increased	Decreased×	Decreased	Extra thoracic restriction: Obesity/Kyphosis
Normal/ Increased	Restrictive pattern	Normal/ Increased	Decreasedα	Decreased	Intra thoracic restriction: Interstitial lung disease

× In case of extrathoracic restriction the decrease in DLCO is in proportion with the decrease in TLC.

α In case of intrathoracic restriction the decrease in DLCO is much lower than the decrease in the TLC. i.e,” The value of DLCO is much lower than TLC”.

Issue 159 - September 2, 2010





**********************************************



IN THIS ISSUE:



IMPORTANT INFORMATION ON TRANSITION TO ECFMG 2011 INFORMATION BOOKLET

AND APPLICATION MATERIALS



- AVAILABILITY OF 2011 INFORMATION BOOKLET AND APPLICATION MATERIALS

- INCOMPLETE IWA APPLICATIONS WILL BE DELETED ON SEPTEMBER 14

- NEW REQUIREMENT FOR ECFMG CERTIFICATION



**********************************************





AVAILABILITY OF 2011 INFORMATION BOOKLET AND APPLICATION MATERIALS



The ECFMG 2011 Information Booklet and the 2011 exam application

materials are expected to be available on the ECFMG website on September

15, 2010. In preparation for the transition to the new materials, the

Interactive Web Application (IWA) will be unavailable beginning at

approximately 5:00 p.m. on Tuesday, September 14. IWA is expected to be

available by the end of the day on Wednesday, September 15. All times

are calculated using Eastern Time in the United States.



For Step 1/Step 2 CK, you will be able to use the 2011 materials to

apply for:



- available Step 1/Step 2 CK eligibility periods ending in 2010

(September 2010 - November 2010 and October 2010 - December 2010) and 



- all Step 1/Step 2 CK eligibility periods ending in 2011, beginning

with the November 2010 - January 2011 eligibility period.



For Step 2 CS, you can use the 2011 materials to obtain a 12-month

eligibility period that begins on the date that the processing of your

application is completed.





INCOMPLETE IWA APPLICATIONS WILL BE DELETED ON SEPTEMBER 14



As part of the transition to the 2011 materials, IWA applications that

have been saved but not submitted will be deleted. If you have a saved

application, you must complete the application, including payment, by

5:00 p.m. on September 14. All times are calculated using Eastern Time

in the United States. If, when IWA becomes unavailable on this date, you

have begun but not yet submitted the on-line part of an exam

application, your incomplete application will be deleted. If your

application is deleted, you will be required to begin a new application

in order to apply for examination.





NEW REQUIREMENT FOR ECFMG CERTIFICATION



Concurrent with the transition to the 2011 materials, the Application

for ECFMG Certification will become a requirement for ECFMG

Certification. Effective on this date, international medical

students/graduates must submit an Application for ECFMG Certification

before they can apply to ECFMG for examination. 



The Application for ECFMG Certification consists of questions that

require applicants to affirm their identity, contact information, and

graduation from or enrollment in a medical school that is listed in the

International Medical Education Directory (IMED) of the Foundation for

Advancement of International Medical Education and Research (FAIMER). As

part of the application, international medical students/graduates must

also confirm their understanding of the purpose of ECFMG Certification

and consent to a release of legal claims. Once submitted to ECFMG, an

Application for ECFMG Certification typically will remain valid

throughout the ECFMG certification process. 



The Application for ECFMG Certification will be available through IWA on

the ECFMG website. There is no fee associated with the Application for

ECFMG Certification. 



See Application for ECFMG Certification in the 2011 Information Booklet.

Pulmonary Function Test

What do you need to know:

1.       The definition of Lung volumes and capacities.

2.       How can you measure Lung volumes and capacities.

3.       Factors Affecting Functional residual capacity.

4.       What is “Dead space”.

5.       High yield Pulmonary Function tests.

6.       What is FEV1/FVC ratio, and how to interpret it.

7.       How to interpret Flow volume loops.

Lung Volumes and Capacities

Figure1: Lung Volumes and Capacities1

A 62-year-old Caucasian man presented to the physician because of a productive cough and dyspnea on exertion. He denies hemoptysis, chest pain, and leg swelling. He has smoked one pack of cigarettes daily for 30 years and drinks 2-ounces of alcohol daily. His temperature is 37.2 C, blood pressure is 140/80 mmHg, pulse is 80/min, and respirations are 20/min.

His chest x-ray shows prominent bronchovascular markings and mild diaphragmatic flattening.  What is the most likely diagnosis if:

1. His pulmonary function testing shows decreased FEV1/FVC ratio and normal DLCO.
2. His pulmonary function testing shows decreased FEV1/FVC ratio and decreased DLCO.

i think the following sequence is very reliable in order to get a 99 score in step1, it worked for mem hopefully it would be useful..

1.Kaplan lecture notes for all the subjects.

2.after finishing each subject u review the first aid book.

3.then do the kaplan Qbook quetions concerning the specific subject.

4.apply this sequence to all subjects

5.finally http://www.usmleworld.com, it helps you learn how to manage your time during the exam and puts great emphasis on topics likely to appear on the exam. dont get dissapointed if it is difficult for you coz it is difficult&dont forget to take  notes

6.review the first aid book again and may be the pathology and the pharma.

hope this will help someone

khalid

this is the first time i post something here but definitly it wont be the last, and i hope i'll be part of this one day:)

the issue of visas is a nightmare to all of us sudanese who are welling to make it to USA and i really dont know if its overrated, honestly i havent heard from anyone who got a visa so i dont know a lot about that... my question:

what is the type of  visa that grants u the entrance to USA, say for taking the CS exam?!

and say im just a regular sudanese guy who doesnt have connections so the issue of getting a J1 visa is out of question, what are the chances of him getting an H1b visa.. provided he took the exam?!

im sorry if u previousy mentioned this, im new here and i took my step1 exam on feb. and got (232, 99).. wish me luck with the rest

it relies on understanding the score

ur 3 digit score counts ur overall performance on the exam regardless of the exam difficulty.

however the 2 digit score takes in consider the difficulty level..so makes results of all candidates comparable..

this is why some people get 227 with 99 others

                                           227 with 91

 hope that helps

source of inforamtion

googling and checking forums for same question !!

Hi everybody, Ramadan Kareem 

Here is the answer for the last week question.

An easy way to remember these concepts is:

Sensitivity = true positives/all diseased

Specificity = true negatives/all normal

PPV = true positives/all positives

NPV = true negatives/all negatives

Prevalence = all diseased/total population

Accuracy = true positive + true negative/total screened patients

Accuracy:

• Total percentage correctly selected.
• The degree to which a measurement or an estimate based on measurements, represents the true value of the attribute that is being measured.

If you prefer charts and formulas:

Sensitivity = a/(a + c) = 100/100+20 = 83%

Specificity = d/(b + d) = 950/ 50+950 = 95%

PPV = a/(a + b) = 100/100+50 = 67%

NPV = d/(c + d) = 950/20+950 = 98%

Prevalence = (a + c)/(a + b + c + d)  = 100+20/100+20+50+950 = 11%

Accuracy = (a + c)/(a + b + c + d)  = 100+950/1120 = 94% 

Wish you the best of luck.

Most score reporting of Step 2 CK results occurs within four weeks of testing. However, because of necessary modifications to the test item pool, there will be a delay in reporting for some examinees testing beginning in mid-August 2010. The target date for reporting Step 2 CK scores for most examinees testing from August 12 through mid-September will be Wednesday, October 6, 2010.

It is possible that scores will be available earlier than this date; please check the USMLE website for updates.

As stated in the USMLE Bulletin of Information, the level of proficiency required to meet the recommended minimum passing level for each USMLE Step examination is reviewed periodically and may be adjusted at any time.

As a result of such a review for USMLE Step 2 Clinical Knowledge (CK), the Step 2 Committee decided to raise the three-digit score recommended to pass Step 2 CK from 184 to 189. In addition, the Committee decided to closely monitor performance trends in the coming year and to re-examine minimum passing requirements in 2011.

The new minimum passing score will be applied to Step 2 CK examinations for which the first day of testing is on or after July 1, 2010.

Cohort Studies

Objectives:

1. To know the meaning of relative risk and attributable risk.
2. How to analyze the data from cohort study and compute the relative risk and attributable risk.
3. How to interpret the result. 

Relative Risk:

Compares the disease risk in the exposed population to the disease risk in the unexposed population.

In other words incidence rate in exposed group/ incidence rate in non-exposed group.

Incidence rate in exposed group = [A/A+B]

Incidence rate in non-exposed group =  [C/C+D]

Relative Risk = [A/A+B] ÷ [C/C+D]

Attributable Risk:

Number of cases attributable to one risk factor.

In other words the amount by which you can expect the incidence to decrease if a risk factor is removed.

So attributable risk is equal to the incidence rate in exposed group – incidence rate in non-exposed group.

Attributable  Risk = [A/A+B] - [C/C+D]

Example

Analyze the data from this cohort study calculating the relative risk and attributable risk?

Relative Risk = [A/A+B] ÷ [C/C+D] 

= [659/1643] ÷ [25/373] = 179907/41075 = 4.4

Interpretation:

Compared  with non smokers, smokers are four times likely to develop lung cancer.

Attributable  Risk = [A/A+B] - [C/C+D]

= [659/1643] - [25/373] = 0.4 – 0.07 = 0.33

Interpretation:

If  the incidence rate of lung cancer in the non-smokers is 7/100 and in smokers it is 40/100, the attributable risk of smoking  in causing lung cancer is 33/100. 

Case- control Studies

Objectives:

1. To know the definition of odds and odds ratio.
2. How to analyze the data from case control study and compute the odds ratio.
3. How to interpret the result. 

Odds:

Probability that an event will happen divided by the Probability that an event will not happen.

Odds Ratio:

Odds of exposure for cases divided by odds of exposure for controls.

Example No One:

The odds that a person with lung cancer was a smoker versus the odds that a person without lung cancer was a smoker

Answer:

Case control study is a retrospective study where you start with the outcome and you go back in time looking for risk factors (exposure).

So first lets first agree upon our variables:

Odds ratio = Odds of exposure for cases/Odds of exposure for controls

Odds of exposure for cases = No of those who have lung cancer and were smokers/No of those who have lung cancer and were not smokers = A/C

Odds of exposure for controls = No of those who have no lung cancer and were smokers/No of those who have no lung cancer and were not smokers = B/D

OR = A/C ÷ B/D = AD/BC

OR = 659 × 348/984×25 = 9.32

Interpretation:

The odds of having been a smoker are more  than nine times greater for someone with lung cancer compared with someone without lung cancer.

Example No Two:

How would you analyze the data from this case-control study?

Answer:

OR = AD/BC = 60×200/120×20 = 5

Interpretation:

This means the odds of having a family history of colorectal cancer are five times greater for those who have the disease than for those who do not.

Putting the pieces together

Objectives:

1. To know the definition of sensitivity, specificity, PPV and NPV.
2. How to compute sensitivity, specificity, PPV and NPV.

Sensitivity:

The probability that the test will be positive when the disease is present.

Sensitivity will answer the following question?

How many patients with the disease will have a positive test result?

Sensitivity = A/A+C

Example:

An experimental diagnostic test is developed to noninvasively detect the presence of trisomy 21, Down's syndrome. The test is administered to a group of 500 women considered to be at risk for a Down's fetus based on blood tests. The results of this test are shown above. What is the sensitivity of this new test?

A. 40%                                                                 

B. 50%

C. 67%                                                                  

D. 71%

E. 83%

So sensitivity determines the ability of a test to detect the presence of a disease in those who truly have the disease.

Positive predictive value:

The probability that, if the test result is positive, the patient truly does have the disease.

PPV will answer the following question?

How many persons with a positive test result will truly have the disease?

PPV= A/A+B

Example:

The table below summarizes the results of a new test to identify patients with an acute myocardial infarction (AMI). The test was performed on 400 subjects.

If one of the 400 subjects in the study is randomly chosen, what is the likelihood that an abnormal test indicates that the individual has an AMI?

A. 0.50                                                                 

B. 0.60

C. 0.68                                                                  

D. 0.80

E. 0.85

Positive predictive value determines the likelihood that an abnormal test (+ve) indicating the presence of disease.

Specificity:

The probability that the test will be negative when the disease is absent.

Specificity will answer the following question?

How many patients without the disease will have a negative test result?

Specificity = D/B+D

Example:

Researchers are assessing the specificity of a screening procedure for breast cancer in a population of 3000 women whose mothers had the disease. The presence or absence of a malignant condition is established by conventional mammography, which is assumed to be definitive for the purposes of comparison. The following data are collected: What is the specificity of the test?

A. 90/100

B. 90/450

C. 2540/2550 

D. 2540/2900

E. (90+2540)/3000

Negative predictive value

The probability that, if the result is negative, the patient truly does not have the disease.

NPV will answer the following question?

How many persons with a negative test result will truly have no disease?

NPV= D/C+D

Example:

The table below summarizes the results of a new test to identify patients with an acute myocardial infarction (AMI). The test was performed on 400 subjects.

If one of the 400 subjects in the study is randomly chosen, what is the likelihood that a normal test indicates that the individual has an no AMI?

A. 0.50                                                                 

B. 0.60

C. 0.68                                                                  

D. 0.80

E. 0.85

Question of The Week

An experimental serologic test is developed to detect the presence of HIV antibody. Epidemiological analysis reveals the results shown below.

Calculate the following:

1.    Sensitivity.

2.    Specificity.

3.    PPV.

4.    NPV.

5.    Prevalence.

6.    Accuracy.

N.B. The answer will be posted next Friday/Please post your answers below.

Review material of the topic will be posted in the USMLE Preparation Material section.