Notes from the book Risk Savvy

Book: https://www.amazon.com/Risk-Savvy-Make-Good-Decisions/dp/0143127101

Certainty is an illusion

1000 German adults were asked face-to-face – “Which of the following TEST are absolutely certain?”

  • Expert Horoscrope
  • Mammography
  • HIV Test
  • Fingerprint
  • DNA Test

Ask this question to yourself as well!

Correct answer is NONE.

NO Test results are absolutely certain.

When Modern technologies are involved, the illusion of certainty is amplified. In-fact, nothing is certain and all of these test makes error.

==================Medical Notes===============

Summary:

  • No Medical TEST RESULTS Are absolutely certain
  • All Screening / Test has False Positive (ASK the doctor or google the same) and understand the percentage of false positive
  • If you are detected positive in any test – do at least couple of more screening to confirm.
  • Early Detection not necessary results into decreasing the mortality rate.

About False Positive Test Result

Many of use believe that the test results of various health test are 100% accurate.

Unfortunately, that’s not the case.

All devices have errors and they do show False Positive Test for a particular disease even if you don’t have it. Each machine/ test has a different False Positive Rate.

Please find below few false positive rates of:

For HIV Test – it is 1 in 250,000 (one of the best false positive rate)

For Mammogram:

False-positive rates ranges from 2.6% to 15.9%.

Between 3 – 16 patients wrongly detected positive. This is HUGE.

Source and Another Research

For Sonography (or Ultrasound):

False-positive rates range is around 9% (9 out of 100 patient wrongly detected positive)

Study Source

Study 2 Source

What this means?

  • If you are tested positive, it’s not necessary that you have that disease for sure. You might want to do few more test to confirm.

Does Early Detection / Screening reduces the Mortality Rate / Death Rate?

Short Answer: NO

Prostate Cancer

Here’s a study done on prostate cancer that shows that Men who did regular screening vs men who didn’t and if it helped reduced the mortality rate:

The results shows that, after an average 7 years of follow-up, the mortality did not significantly differ between the 2 groups.

Source

Breast Cancer

Out of every 1000 women who did not participate in screening, about 5 died of breast cancer, while number was 4 for those who participated.

In statistical terms, that is an absolute risk reduction of ONLY 1 in 1000.

Source

^^ Most doctors / people are fooled with the understanding that early detection results into decreasing the mortality rate

^^ Some cancers are non-progressive and that results into decreasing the mortality rate. The patient may not take any medicine but due the nature of it’s cancer he is going to die due to some other reasons before his cancer actually becomes his reason for death. Doctors may consider these patients as their success however that may not be the case.

=======================================================

Why Doctors DO NOT Promptly Share these information?

The author has coined a term SIC SYNDROME for doctors.

  • Self Defense
  • Innumeracy
  • Conflicts of Interest

Self Defense:

  • Most doctors are worried about a situation when they didn’t found any symptoms in a patient through manual checkup BUT do not want take a chance (and to protect) their image, they recommend extra test / screenings
  • Since People trust the screening results (as shared in the study at the beginning) – Doctors have an absolute proof to show it to the patient that they do / do not have any risk.
  • This is one of the biggest reason doctors recommend screening and tests to protect their down side

Innumeracy

  • The inability to think with numbers. Doctors are not trained to communicate the risk of any test to the patients.
  • There are lot of research papers out there however since doctors are not trained to read them well statistically they misinterpret the data and results into wrong risk communication to patient.
  • A famous example of wrong miscommunication is – Early detection can result into 20 percent risk reduction in Breast cancer. Here, 20 Percent risk reduction is in relative terms. In absolute terms it is 1 in 1000 women which is super low

Conflicts of Interest

  • Doctors may have an interest to earn more and hence recommend an unnecessary screening
  • According to the points mentioned in the book, Big hospitals have targets of doing X Surgeries and Y Screenings every month irrespective of the condition of the patient. This results into unnecessary screening or test of patient to earn money

 

============== Additional Notes from the book=========

When the weather reporter announces a 30% chance of rain, what does it mean?

> It means there is 3 out of 10 chance you will get wet. It DOES NOT mean that only 30 percent of the area will get the rain OR some specific hours it will be rainy.

A good article on this subject

There is a HUGE misconception among people about it’s actual meaning due to lack of communication from the authorities as to what the 30% actually mean 😦

Notes on Leadership to Manage People:

  • First listen, then speak
  • If a person is not honest and trustworthy the rest doesnt matter
  • Encourage people to take risk and empower them to make decisions and take ownerships

Strategy:

  • Innovation drives success
  • You can’t play it safe and win. Analysis will not reduce uncertainty
  • When judging a plan, put as much stock in people as in the plan

In the face of uncertainty ‘intuition’ is indispensable for decision Making: 

An example of this is US Airways Flight 1549 Read More

Had the pilot spend time in going through the checklist while the flight’s engine were shut it couldn’t have been saved. Instead the captain use a simple rule of thumb – which helped him do a successful land in HUDSON River.

An Intuition or gut feeling is a judgement:

  1. that appears quickly in consiceneness
  2. whose underlying reasons we are not full aware of
  3. is strong enough to act upon

Simple Point: Ignoring tons of information can lead to  better, faster and safer decision.

 

 

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