Consult Doctors. FREE.
Real Doctors, Expert Answers
Connect with Facebook Connect with Google For Doctors
By creating an account, you are indicating that you have read and accepted the DoctorXDentist Terms of Use.
Consult Doctors. FREE.
Real Doctors, Expert Answers
By creating an account, you are indicating that you have read and accepted the DoctorXDentist Terms of Use.
Registration Progress
Step 1: Indicate Topics of Interests
Step 2: Follow Relevant Doctors
Complete!
What are your interests?
Please select at least 3 interests.
NEXT
NEXT
Registration Progress
Step 1: Indicate Topics of doctors
Step 2: Follow Relevant Doctors
Complete!
Follow your favourite doctors
We found some doctors you may like. Click continue to follow them.
CONTINUE
CONTINUE
Consult Doctors. FREE.
Real Doctors, Expert Answers
Continue with Facebook Continue with Google

or

OOPS!

SOMETHING WENT WRONG.

PLEASE TRY AGAIN.

OOPS! SOMETHING

WENT WRONG.

PLEASE TRY AGAIN.

YOUR QUESTION HAS BEEN

SUCCESSFULLY SUBMITTED.

OUR DOCTORS WILL GET BACK TO YOU SHORTLY!

Disclaimer: Any answers provided are for general informational purposes only and is not a substitute for professional medical advice. If you think you may have a medical emergency, call your doctor immediately. Always seek the advice of your doctor before starting or changing treatment.

YOUR QUESTION

HAS BEEN

SUCCESSFULLY

SUBMITTED.

OUR DOCTORS WILL GET

BACK TO YOU SHORTLY!

Disclaimer: Any answers provided are for general informational purposes only and is not a substitute for professional medical advice. If you think you may have a medical emergency, call your doctor immediately. Always seek the advice of your doctor before starting or changing treatment.

YOUR QUESTION HAS BEEN

SUCCESSFULLY SUBMITTED.

YOUR QUESTION

HAS BEEN

SUCCESSFULLY

SUBMITTED.

YOUR ANSWER HAS BEEN

SUCCESSFULLY SUBMITTED.

YOUR ANSWER

HAS BEEN

SUCCESSFULLY

SUBMITTED.

YOUR QUOTE REQUEST HAS BEEN

SUCCESSFULLY SUBMITTED.

OUR DOCTORS WILL GET BACK TO YOU SHORTLY!

YOUR QUOTE REQUEST

HAS BEEN

SUCCESSFULLY

SUBMITTED.

OUR DOCTORS WILL GET

BACK TO YOU SHORTLY!

YOUR THREAD HAS BEEN

SUCCESSFULLY CREATED.

HEAD OVER TO FORUM PAGE NOW

TO JOIN THE DISCUSSION

YOUR THREAD

HAS BEEN

SUCCESSFULLY

CREATED.

HEAD OVER TO THE FORUM PAGE NOW

TO JOIN THE DISCUSSION!

YOUR REVIEW HAS BEEN

SUCCESSFULLY SUBMITTED.

THANK YOU.

YOUR REVIEW

HAS BEEN

SUCCESSFULLY

SUBMITTED.

THANK YOU.

OOPS!

THERE IS SOMETHING

WRONG WITH YOUR EMAIL.

PLEASE TRY AGAIN.

OOPS! THERE IS

SOMETHING WRONG

WITH YOUR EMAIL.

PLEASE TRY AGAIN.

YOUR EMAIL HAS BEEN

SUCCESSFULLY SUBSCRIBED.

THANK YOU.

YOUR EMAIL

HAS BEEN

SUCCESSFULLY

SUBSCRIBED.

THANK YOU.

YOUR CONSULTATION HAS BEEN

SUCCESSFULLY SUBMITTED.

OUR DOCTORS WILL

GET BACK TO YOU SHORTLY.

YOUR CONSULTATION

HAS BEEN

SUCCESSFULLY

SUBMITTED.

OUR DOCTORS

WILL GET

TO YOU

SHORTLY.

MESSAGES TO

Should Everyone Be Tested For Everything?

A doctor who failed to diagnose a rare disease in a child recently drew flak in local news. Comments emerged divided. A kiasu-kiasi Singaporean like me might say “yes we should send everybody for testing so this doesn’t happen again!”

1. Should we really be testing everyone?

But if every single person were to be tested for diseases they might not be at high risk for, it is going to cost the public healthcare system too much, and might drain resources from actually treating diseases.

Before we agree too quickly with the usual cost-containment narrative, there is another side of the story we ought to look at.

Preventive medicine, although it has “medicine” in its name, is about helping patients NOT have to take medicine! It is about taking steps to identify people at high risk, to prevent a disease from developing or nipping it in its early stages.

Screening and diagnostic testing play a big role in preventive medicine as they allow healthcare providers to assess your risk for a disease and need for further testing and treatment.

2. Unfortunately, screening tests are not fool-proof

Screening tests are by definition, a simple test performed on a large number of people to identify those who have or are likely to develop a specified disease. However, no screening test can tell with 100% accuracy that someone has the disease.

Having a positive screening test result might NOT necessarily mean you have the disease, and vice versa when it returns negative.

To illustrate, let’s pretend that somebody has breast cancer. We can screen for breast cancer using mammography, but the only way to confirm that a person indeed has breast cancer is by doing an invasive breast biopsy.

doctorxdentist

After a mammography screening test, this person falls in one of the four grey boxes. True positives and true negatives are useful results, because you know the person definitely has or doesn’t have cancer.

The other 2 possible results highlighted in red? Well, not so much.

  1. A false positive is when she thought she had the cancer, but she doesn’t.
  2. A false negative is when she thought she was all-clear, but nope, she has cancer.

False negatives (and false positives) are instances when the test does not accurately predict the truth. And these happen for all screening tests – no test is perfect! 

3. The perfect screening test

The most ideal screening test would have minimal false negatives (high SENSITIVITY) and minimal false positives (high SPECIFICITY).

Sensitivity and specificity are concepts about the test method itself. It’s kind of like how good the test is at classifying someone as having or not having a disease.

With advancements in science, screening tests are getting closer and closer to predicting the truth, but it's important we keep this in mind when thinking about increasing the use of screening tests.

4. Bonus: Positive and negative predictive values (for the extra geeky)

From a patient’s perspective, I want to know how likely I have the disease, if my test result is positive ie. how likely do I have breast cancer if my mammogram comes back positive.

This brings us to positive (PPV) and negative (NPV) predictive values of a test. Compared to sensitivity and specificity, PPV and NPV depend on the number of people who have the disease – also known as “prevalence”. 

Rare diseases like Kawasaki only affect a few people in the population – about 30 cases per 100,000 children under-5 – that’s only about 0.03%! When prevalence is low, the likelihood that you really have the disease will be low (low PPV), even with a test of high sensitivity and specificity.

In normal speak, it means that most of those screened “positive” will eventually be found not to have the disease upon further testing. This factor probably accounted partially for why Dr Chia decided against ordering any tests to rule out Kawasaki disease for her patient - imagine all the unnecessary worry that parents have to suffer if every doctor started ordering these tests for their febrile children.

I think that's probably enough content for an article you're probably just scrolling through on your smartphone. But if you are still intrigued by the science of screening tests (like me), check out this academic review.


I hope this helps to aid understanding of health screening tests, and how over-using them might not be the answer to the problem of under-diagnosing certain conditions.

For Singaporeans, the Screen for Life programme run by HPB has an online tool to find out what screenings are best suited for yourself, friends and family. Information on subsidies are also available.

Sarah is a fully registered pharmacist with the Singapore Pharmacy Council. She’s currently working towards completing a further degree in public health. Things that excite her include a good book, a good cup of coffee and being able to help people use medicines safely.

784 views 0 Doctors agree 31 Jan 2018
SHARE
Not the answer you're looking for? Browse other answers tagged Health Screening Singapore Healthcare or ask your own question now FOR FREE.

Get Doctor Quotes

Name of Treatment
Category
Budget
Full Name
Email
Contact Number
Other Information
Contact By Phone
Contact By WhatsApp