Saturday, May 5, 2012

Sensitivity and screening

A good screening test is very sensitive. This means it picks up most cases of the disease so a negative result tells you with good level of certainty that the disease is absent. Thus a good screening test "rules out".  It therefore also has high number of false positives.
It is usually not very specific, i.e if it is positive, it may be due to something other than the disease but it must be very sensitive i.e if it is negative, the disease is most likely absent.

Expl is the Overnight Dexamethasone suppression test for Cushing's syndrome
If cortisol drops : Cushing's is ruled out
However, if cortisol remains high, it may be Cushing's or Stress or something else i.e it's not specific

Also, ESR for temporal arteritis
If low, TA is ruled out
If high, there are several inflammatory diseases that could be responsible so it's not specific

Sensitivity rules out with its negative results, SnOut, specificity rules in with its positive results, SpIn

A confirmatory test is therefore highly specific for the particular disease or event.

2 comments:

  1. God bless Dr. USELU for his marvelous work in my life, I was diagnosed of HERPES SIMPLEX VIRUS since 2018 and I was taking my medications, I wasn't satisfied i needed to get the HERPES out of my system, I searched about some possible cure for HERPES i saw a comment about Dr. USELU , how he cured HERPES with his herbal medicine, I contacted him and he guided me. I asked for solutions, he started the remedy for my health, he sent me the medicine within 3 days. I took the medicine as prescribed by him and 2weeks later i was cured from HERPES contact him via email (dr.uselucaregiver@gmail.com) once again thanks to you Dr. USELU cure the flowing virus, contact his email or add him on whatsapp (+2349019328641) cancer cure
    diabetes cure
    ringing ear
    herpes cure
    warts cure
    HPV cure
    HIV cure
    get your ex back
    pregnancy herbal medicine
    Hepatitis  

    ReplyDelete
  2. Investing online has been a main source of income,that's why knowledge plays a very important role in humanity,you don't need to over work yourself for money.All you need is the right information,and you could build your own wealth from the comfort of your home!Binary trading is dependent on timely signals,assets or controlled strategies which when mastered increases chance of winning up to 90%-100% with trading. It’s possible to earn $10,000 to $20,000 trading weekly-monthly,just file a complaint with  Robert,I had almost given up on everything about binary trading and ever getting my lost funds back,till i met with him,with his help now i have my lost funds back to my bank account and I can now trade successfully with his profitable strategies and software!! Email: Robertseaman939@gmail.com or Fb.me/investandmakemoney1 or  whatsApp: +44 7466 770724

    ReplyDelete