Let us look at the sample NBME question below:

A randomized controlled trial is conducted to compare a new oral proton pump inhibitor with oral omeprazole for the prevention of recurrent duodenal ulcer bleeding. A total of 2000 patients with newly diagnosed duodenal ulcer who have had recent bleeding are randomly assigned to receive the new drug or omeprazole. After 1 month, results show that 4% of patients treated with the new drug have recurrent ulcer bleeding compared with 5% of patients treated with Omeprazole (p<0.05). Based on these results, how many patients would need to be treated with the new drug to prevent one recurrent duodenal ulcer bleed?

A.    A. 10

B.    B. 40

C.    C. 50

D.    D.100

E.     E. 200

Dissecting the question

The question targets number needed to treat.

To answer this type of question asking “Number Needed to Treat” you need to remember Absolute Risk Reduction [ARR] (That is how much risk is taken away after exposure or treatment, ARR is gotten when the exposed group is subtracted from the unexposed group)

The formula for Absolute Risk Reduction (ARR): Unexposed group – Exposed group = ARR

To get absolute risk reduction from the question, we need the number of patients who were treated with a new drug (4%) and the number of patients treated with Omeprazole (5%).

ARR = 5 – 4 = 1%

Convert percentage to number = 1/100 =  0.01

The formula for Number Needed to Treat: 1 / ARR

Number needed to treat = 1/0.01 = 100

The answer is D.100

Surgery rotations at the EFTSH, Banjul, The Gambia was really interesting and impactful. Everyone was friendly and patient, a prerequisite for a successful rotation.

A Brief Opinion based on my experience.

The rotations were standard when you want to compare to similar rotations in countries like Nigeria, The Caribbean’s, etcetera (I was able to do some comparison with some friends in these countries).

The Consultants are really kind and understanding, they would try to teach you as much as you need to know.

It is very important that you study before you start your surgery rotations because your superiors (Consultants, Registrars, Medical officers and House officers) would expect that you already know a lot from Basic sciences and previous rotations.

They are going to ask you a lot of questions, don’t run away. Be bold, give answers to questions you know, attempt the ones who have an idea of and politely excuse yourself for those you have no knowledge.

Some of the consultants took note of their students, they noticed how much questions you answer during the rounds, they also notice your punctuality and probably many other salient characters I can’t point at now. That way they have a mental picture before the examination. The point is, you may earn your marks even before the examination day, so study before your rounds at least.

Clerking of patients, cannot be over emphasized. Practice clerking as often as possible, say at least one patient per day. You can clerk/follow up your patients for better understanding of the cases, this would boost your confidence for the long case examination.

Time management is really important in clerking, if you know the local languages (Wollof, Mandika, Fula etcetera) you are in luck.

Surgery rotation's most common/High yield topics.

I have compiled a list of the most popular/high yield topics that was encountered during our rotations, most would be tested during ward rounds, out patients and surgical procedures and others would be tested during the examination.

The list below may not be complete, but if you are able to cover most, I will bet on you for the student surgery examination whether it be in The Gambia, West Africa or The Caribbean’s (These I have knowledge of).

I will prepare notes on most of these topics and place the links here. Guide yourself with these topics and always check back to see if I have updated the links to my notes here. These notes would be of great help to you, especially in forming the base for your studies.

This list is in no particular order. You may read/order according to most common cases during your rotations (Ward rounds, surgeries and outpatients) as most questions asked during ward rounds are based on the cases on ground.

1.  Pre-operative (Before surgery/operation) and Post-operative (after surgery/operation) management

2.   General Physical Exam

3.    Factors affecting wound healing

4.    Wound classification

5.    Process of wound healing

6.    Factors affecting wound healing

7.    Appendicitis

8.    Diabetic Foot Examination

9.    Classification of Diabetic foot

10. Ulcers

11. Description of Ulcers

12. Types of Amputations

13.   Indications for Amputation

14.  Complications of Amputation

15.  Jaundice

16.  Anatomy of the foot

17.  Deep Venous Thrombosis (DVT)

18. Pulmonary Embolism and Virchows triad

19.   Intestinal Obstruction

20.  Complications of Intestinal Obstruction and their Treatment

21.  Pneumothorax

22.  Classification of pneumothorax

23.  Curvesoirs sign

24.  Peritonitis

25.  GI bleeding

26.  Hernia (Really high yield)

27.   Urine output

28.   Hirschprung disease

29. Peptic Ulcer Disease – types and complications

30.   Cholecystitis

31.   Pancreatitis

32. Gastric Outlet Obstruction (Inability of Gastric content to go beyond proximal duodenum)

33. Upper Motor Neurons  and Lower Motor Neuron lesions (for the neurosurgeon)

34. Factors that impair/prevents Wound healing

35.    Surgical site infection

36.    Charcot Triad and Reynolds Pentad

37. Necrotizing fasciitis (Deep Spreading infection affecting the fascia planes)

38.    Acute Abdomen

39.  Gangrene (A type of Necrosis of body tissue. Types: Dry, Wet, Gas, Founier)

40.    Septic foot

41. Spinal Injury (Motor deficits, Abnormal/Decreased sensations)

42.   Cellulitis

43.   Colon cancer

44.  Transfusions (Whole blood, PRBCs, FFP, Cryoprecipitate, Platenlets)

45.   Diabetes

46. The Diaphragm (Supply and anatomic relations)

Viva Examination focus

1.  Resuscitation equipment

2.   X-Ray (Chest, Head)

3.    CT scan

4.    Cannula

5.    Catheter

6. Fluids & Crystalloids (Composition & Uses)

7.     NG tube

8.     Endotracheal tube

9.      Surgical Instruments

Short case Examination focus

1.     Neck swelling

2.     Hernia/Groin mass

3.     Breast mass

4.     Hirschsprung disease

Neurology focus

I will suggest you pay attention to these topics for neurology.

I remember the neurosurgeon liked these topics. He even openly said he would not forgive anyone who fails to answer questions on the Glasgow Coma Scale.

1. American Spinal Injury Association (ASIA) classification of spinal injury

2.   Dermatomes

3.     Types of spinal cord injury

4.  History and Physical Examination of the Neurologic system

5.                  Glasgow Coma Scale (GCS)

6.                  Hydrocephalus

7.                  Spina bifida and anencephaly

Please note:

This list covers only Surgery 1 rotations.

Answering Biostatistics questions for IFOM and the USMLE: Part 1

Let us look at the sample NBME question below:

A community public health department has a limited budget for new interventions and must decide between two options. Option A is to reduce exposure to an industrial chemical that increases the risk for leukemia from 0.5 per 100,000/year to 2.0 per 100,000/year. It is estimated that 30% of the working population in the community is exposed to this agent. Option B is to reduce exposure to a different toxin that increases the risk for aplastic anemia from 0.5 per 100,000/year to 50 per 100,000/year. It ¡s estimated that 5% of the working population is exposed to this toxin. The estimated cost of each intervention is US $740,000. It is assumed that each intervention program will have similar effectiveness in eradicating the exposure. The case fatality rates are similar for both diseases. Which of the following is the best rationale for the health department to use in selecting an option?

A) Option A because more fatalities will be prevented

B) Option A because more workers are exposed to the toxic agent

C) Option B because more fatalities will be prevented

D) Option B because more workers are exposed to the toxic agent

E) The best approach cannot be determined based on the information provided

Dissecting the question

- This question targets the topic: Relative Risk [Relative risk is a high yield topic]

- The quick formula for Relative Risk for this purpose is to divide:

 Exposed group (or no treatment) / Unexposed group (or with treatment)

- What these kinds of questions ask, is for you to compare the risk of Option A relative to Option B.

- Every other information in the vignette isn’t needed to arrive at the answer.

- You can easily spot this type of question by looking for the keyword “Risk” when you are asked to compare one group to another (Just like the above question).

Solving for an answer:

From Option A (Risk for leukemia):

Exposed group = 2

Unexposed group = 0.5

Putting in the formula:

2/0.5 = 4% (Relative Risk of 4)

From Option B (Risk for aplastic anemia):

Exposed group = 50

Unexposed group = 0.5

Putting in the formula:

50/0.5 = 100% (Relative risk of 100)

So the Risk in Option B is 100% relative to that in Option A which is 4%. 

It means it would be better to invest in an intervention that would reduce the risk of disease by 100% than to invest in one that reduces the risk by only 4%.

The answer is "Option C) Option B because more fatalities would be prevented".

It is not “D) Option B because more workers are exposed to the toxic agent” because we are working with the risk increased per year in each option (i.e 100,000/yr), we are not working with the percentages of workers exposed to the agents. The reason is, even though 30% of workers are exposed to Option A’s agent the risk of getting leukemia is 4%. For Option B, only 5% of the working population is exposed to it, but the risk of getting aplastic anemia is 100% from the calculation.

Take home:

When you meet any biostat question that wants you to compare risk in one group to another,

- Remember relative risk

- Extract exposed numbers and unexposed numbers from the questions

- Divide E (exposed) with U (unexposed) [E/U = RR]

- The group with the highest number has the more risk and vice versa.

- Every other information from the vignette may not be helpful

- All the methods or assumptions in these questions might not be perfect but if you grasp the concept, you'll find it easy to answer similar questions.

Reference:
1. Topic: Relative Risk. Book: First Aid for the USMLE step 1 2019. Public Health Sciences/Biostatistics section.

welcome to my page my Great readers, in this article I am here to educate you about some foods you are probably consuming excessively but may not know how dangerous they are to your kidneys.

WHAT IS KIDNEYS?

The kidneys are two bean-shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of your spine. Healthy kidneys filter about a half cup of blood every minute, removing wastes and extra water to make urine.

In all human being, they are two kidneys present one at the right hand side and other at the left hand side. And Please remember that they is no body who can live without present of two healthy kidneys.

The kidneys are a very important organ in the body of every human being. They are two bean-shaped organs, each about the size of a fist, located just below the rib cage, one on each side of your spine. The kidneys are responsible for getting rid of waste products, drugs, and toxins through our urine.

Although so many people know that a major function of the kidneys is to remove waste products and excess fluid from the body, but the kidney still perform all functions which may go beyond this alone.

FUNCTIONS OF THE KIDNEYS

1# Healthy kidneys are responsible for getting rid of waste products, drugs, and toxins in your body system which passes through our urine.

2# Healthy kidneys also help in removing wastes, control the body's fluid balance, and keep the right levels of.

3# Healthy kidneys also help in filtering about a half cup of blood every minute, and removing wastes and extra water to make urine

4# your kidney help your body in maintaining Electrolyte balance.

5# Its serve in controlling your blood pressure.

6# Healthy kidneys serve as an organ in producing the hormone called Erythropoietin.

7# healthy kidney help in controlling Acid and base balance in the body system. ETC.

KIDNEYS DISEASES

They are different kinds of kidney diseases but I am going to discuss few among them. Chronic kidney disease, kidney stone, polycystic kidney disease and urinary kidney infection ETC. The most common form of kidney disease among these is Chronic kidney disease, Is a long-term condition that doesn’t improve over time. It’s commonly caused by high blood pressure

SYMPTOMS OF KIDNEY DISEASES

1# you will experience frequent unrination

2# fatigue (tiredness )

3# you will experience Trouble Sleeping (difficulty in Sleeping )

4# you will experience Bad appetite

Haven known some of the functions and important with symptoms of an Affected kidney, I can now go straight to 3 things you need to avoid excess intake of them if you want to live long.

STOP DRINKING TOO MUCH ALCOHOL

Please pay maximum attention to this message, excessive consumption of alcohol can be very bad and dangerous to your kidney. So many People are victim of this particular act because of addiction.

Drinking too much Alcohol causes changes in the function of your healthy kidneys and makes them less able to filter the blood. Which can easily damage the kidney. Excessive consumption of Alcohol also affects the ability to regulate fluid and electrolytes in the body. When alcohol Dehydrates that is, (dries out) the drying effect can affect the normal function of cells and organs, including the kidneys.

Too much intake of Alcohol affects the kidneys' ability to keep the correct balance of water and electrolytes in the body system which lead to kidney infection.

Although if you want to Drink alcohol, little quantity is enough because Moderate alcohol consumption has been shown to be protective in the formation of kidney stones. But you Drink it beyond moderate level, it can easily harm your kidney by causing chronic kidney disease.

STOP ABUSING PAINKILLERS

We are in a society today where painkillers medicine are been abuse by so many People in the society most especially young ones.

Whenever you used pain killers medicines improperly, it can cause different problems in your body, including the kidneys. According to a research, some of the cases of chronic kidney failure each year may be caused by the overuse or abusing of these painkillers drugs.

Taking one or a mix of these medicines daily over a long time without the doctor's prescription may cause chronic kidney problems. That is,. Painkillers that combine 2 or more medicines (such as, aspirin and acetaminophen together) with caffeine or codeine can mostly likely to harm your kidneys. Please take note of that.

STOP EATING TOO MUCH SALT

Salt is good for the body but when they are consume excessively, they can equally harm the kidney. Hope you are following? Many People today eat much quantity of salt without knowing how harmful they are to the kidneys.

high salt intake has been shown to increase the amount of protein in the urine which is one of the major risk factor for the decline of kidney function. There is also increasing evidence that a high salt intake may increase deterioration of kidney disease in people who already have kidney problems.

Salt is also a strong solvent which May likely contain high sodium, and has the ability to dehydrate the kidney when consumed excessively. Please I beg you with the name of God, look for a better supplement for your food in order to limit salt intake because it can cause a big harm to your kidneys.

All images used above are for illustrative purpose. Please share this message to the society and Don't forget to the follow me for more information on my page THANKS.