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  #1  
Old 03-17-2012
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Stats Effect of therapy on AIDs incidence/prevalence!

A 23 year old patient presents to the clinic and is diagnosed with PCR as HIV-positive. You start triple therapy as a standard treatment. What best describes the effect of triple therapy among AIDS patients' population?

A. increased prevalence
B. decreased prevalence
C. increased incidence
D. decreased incidence
E. No effect on the incidence or prevalence due to lead time bias
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i think its A
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answer is [A]
triple therapy.. or any therapy in general for a chronic disease which tends to increase the life span of the patient... by time.. it will lead to more people alive who have AIDS..meaning that the prevalence of the disease has increased

it wont effect the incidence, coz it's not a vaccine or a preventive measure or anything.. so the rate of people getting sick is constant,, it's just that they live longer now

hope it's clear that way ^_^
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The answer is B
The question tells about HIV patient and asks about AIDS population
By using triple therapy less HIV people will progress to meet the definition of AIDS syndrome. So the prevalence of AIDS will decrease NOT increase.
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Increased prevalance- if a drug's working better and prolonging life, the no. of ppl with the disease at a given point of time(i.e, prevalance) increases.
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Quote:
Originally Posted by bunny View Post
The answer is B
The question tells about HIV patient and asks about AIDS population
By using triple therapy less HIV people will progress to meet the definition of AIDS syndrome. So the prevalence of AIDS will decrease NOT increase.

but eventually they will have aids, right? so shouldnt prevalence increase?
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i saw this question in goljan notes thats y i posted to discuss with u guys whats correct option?
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"bunny"

has a point, could be a trick to see if u really grasped the concept, and just memorized a general rule, who knows
i'd still pick [A]
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We give drugs when patients have a CD4 count of 350-500.However, sooner or later the CD4 count will drop to <200 = AIDS. At long term prevalence will increase. Maybe at short term prevalence will be reduced, but at long term, HIV might become the next DM.
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Originally Posted by drhma View Post
but eventually they will have aids, right? so shouldnt prevalence increase?
Prevalence doesn't count what will be in the future, only count till the moment of now... that 's why the population of AIDs pts after tripple therapy is less...
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Quote:
Originally Posted by patho2012 View Post
Prevalence doesn't count what will be in the future, only count till the moment of now... that 's why the population of AIDs pts after tripple therapy is less...
Nop, prevalence is total number of cases of the risk factor in the population at a given time. It can be the prevalence of 10 years ago, the prevalence of this year, or in the one in the future.

Plus, the question is saying what will happen... is talking about the future. The prevalence will not change now if we start giving medicine, we have to wait some time until we can start seeing changes in the prevalence of AIDS.
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Default I have a point..

If you are thinking it is being tricky..then I guess it shouldn't be decreasing the prevalence, but decreasing the incidence..am I right?
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initially i jumped at B

but A makes more sense
when you have AIDS you take therapy so that you can live with AIDS right?
so the prevalence increases.

if the therapy were to cure the AIDS and you become AIDS-free, then the prevalence would decrease.

is that right?
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Quote:
Originally Posted by Dr.Aly View Post
If you are thinking it is being tricky..then I guess it shouldn't be decreasing the prevalence, but decreasing the incidence..am I right?
nothing to do with incidence
incidence is new cases
the amount of new cases wont be affected by the therapy for someone who already has AIDS.
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Originally Posted by Dr.NickRiviera View Post
initially i jumped at B

but A makes more sense
when you have AIDS you take therapy so that you can live with AIDS right?
so the prevalence increases.

if the therapy were to cure the AIDS and you become AIDS-free, then the prevalence would decrease.

is that right?
Yeah... unless we get a new HIV-vaccine or a definitive cure, people with HIV will always end up with CD4 <200 = AIDS.

To put it in a different way, 10 years a go a lot of people was dying because of HIV/AIDS (The prevalence at that time was lower if you compared it to the current prevalence)... However, nowadays we have more people with HIV/AIDS that are still alive because of the new treatment options that are available. As a result, the prevalence of HIV/AIDS has changed. Now we have more people sick but because the life-expectancy in this patients has increased.

Well, at least this is how I see it...
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Just to put it in perspective. In real life this is what is happening with the prevalence and incidence of AIDS. If you see at the bottom of the graphic, you will see that the prevalence of AIDS is increasing year by year... So I guess that the answer should be "A"

http://www.cdc.gov/hiv/topics/survei...overview.htm#1
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Effect of therapy on AIDs incidence/prevalence!-aids-prevalence.jpg  
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the graph says it all...yes, ans B is correct...you just mix all the defs up like a bowl of salads...
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Quote:
Originally Posted by patho2012 View Post
the graph says it all...yes, ans B is correct...you just mix all the defs up like a bowl of salads...
How is it B?

It looks like A to me.
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Quote:
Originally Posted by patho2012 View Post
the graph says it all...yes, ans B is correct...you just mix all the defs up like a bowl of salads...
Really...???

This is how I see it:

AIDS diagnoses = incidence. Is going down because of two thing: 1) because of the antiretrovirals, and 2) people being more careful about it ----> THE INCIDENCE of AIDS has changed because of less people being diagnosed with AIDS.

Death
= mortality rate, this goes down as people tend to live longer. You can see how the antiretrovirals have had a big impact in AIDS mortality. To put it in perspective: in DM or any other chronic disease = less death people means more sick people ---> more prevalence of sick people.

Living with an AIDS diagnosis
(this one sounds pretty straightforward to me) = prevalence. If you see the line at the bottom (The one with the clear circle and a line) it has not changed at all, it keeps going up. This can be because of two things: 1) antiretrovirals and 2) the late Dx of AIDS in some population. The ones with the late seroconversion that were infected before the introduction of the antriretrovirals but because of this late seroconversion they got to use the medicine.

Living with HIV infection
= this is HIV infection prevalence. Again, the antiretrovirals keep the patients living longer without AIDS, but sooner or latter they becomes AIDS. How do I know? You can see this because of the strong relationship among "living with HIV infection" and "living with AIDS diagnosis" lines, they are parallel.

So, after having analyzed the table, we can now make some conclusions regarding the above question:

1. Antiretrovirals have increased the prevalence of HIV and AIDS.

2. It is the incidence not the prevalence of AIDS the one that has been reduced with the introduction of the antiretrovirals.

3. Neither the prevalence of AIDS nor the prevalence of HIV has been reduced with the introduction of antiretrovirals.

So, going back to the Q and the answers... correct answers: A and D (increased prevalence and reduced incidence)

Well, this is how I see this table... What do you think guys?
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Quote:
Originally Posted by Dr. Mexito View Post
Really...???

This is how I see it:

AIDS diagnoses = incidence. Is going down because of two thing: 1) because of the antiretrovirals, and 2) people being more careful about it ----> THE INCIDENCE of AIDS has changed because of less people being diagnosed with AIDS.

Death
= mortality rate, this goes down as people tend to live longer. You can see how the antiretrovirals have had a big impact in AIDS mortality. To put it in perspective: in DM or any other chronic disease = less death people means more sick people ---> more prevalence of sick people.

Living with an AIDS diagnosis
(this one sounds pretty straightforward to me) = prevalence. If you see the line at the bottom (The one with the clear circle and a line) it has not changed at all, it keeps going up. This can be because of two things: 1) antiretrovirals and 2) the late Dx of AIDS in some population. The ones with the late seroconversion that were infected before the introduction of the antriretrovirals but because of this late seroconversion they got to use the medicine.

Living with HIV infection
= this is HIV infection prevalence. Again, the antiretrovirals keep the patients living longer without AIDS, but sooner or latter they becomes AIDS. How do I know? You can see this because of the strong relationship among "living with HIV infection" and "living with AIDS diagnosis" lines, they are parallel.

So, after having analyzed the table, we can now make some conclusions regarding the above question:

1. Antiretrovirals have increased the prevalence of HIV and AIDS.

2. It is the incidence not the prevalence of AIDS the one that has been reduced with the introduction of the antiretrovirals.

3. Neither the prevalence of AIDS nor the prevalence of HIV has been reduced with the introduction of antiretrovirals.

So, going back to the Q and the answers... correct answers: A and D (increased prevalence and reduced incidence)

Well, this is how I see this table... What do you think guys?

dont go crazy my friend, they are just saying that by starting early therapy, you wont actually progress to AIDS, so the prevalence of AIDS will go down, at first glance seems like a give away Q, but they get you
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  #21  
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Quote:
Originally Posted by LatinGeorge View Post
dont go crazy my friend, they are just saying that by starting early therapy, you wont actually progress to AIDS, so the prevalence of AIDS will go down, at first glance seems like a give away Q, but they get you

I really don't get it...
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Originally Posted by Dr. Mexito View Post
I really don't get it...
AIDS is the syndrome, like PCP, TOXO, MAC, you know, all the AIDS defining conditions.

But you can be HIV+ and can be living the vida loca, asymptomatic and then advance to AIDS 10 years later.

All they are saying is that by giving the drug, you can spend most of your life being HIV+ but not advancing to AIDS.

Last edited by LatinGeorge; 03-17-2012 at 07:17 PM. Reason: typo
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  #23  
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Yup i also think that prevalance will decrease its a basic science exam not a CDC researcher exam
Just a humor lol
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Yup i also think that prevalance will decrease its a basic science exam not a CDC researcher exam
Just a humor lol
Does this means that AIDS incidence will also be reduced... right?
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Wawww......
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Wawww......

Welcome to the convo! Suka+r!
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Quote:
Originally Posted by LatinGeorge View Post
AIDS is the syndrome, like PCP, TOXO, MAC, you know, all the AIDS defining conditions.

But you can be HIV+ and can be living the vida loca, asymptomatic and then advance to AIDS 10 years later.

All they are saying is that by giving the drug, you can spend most of your life being HIV+ but not advancing to AIDS.
Yea that makes sense, what a bullshit question.
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where are these questions from?
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Quote:
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Yea that makes sense, what a bullshit question.
haha its a WTF question
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  #30  
Old 04-07-2012
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Default Decreasing incidence..!

Yep, that is what I meant. If you want to go the trickier way then it is decreasing incidence..!
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Quote:
Originally Posted by bunny View Post
The answer is B
The question tells about HIV patient and asks about AIDS population
By using triple therapy less HIV people will progress to meet the definition of AIDS syndrome. So the prevalence of AIDS will decrease NOT increase.
I totally agree
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Old 05-14-2012
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Quote:
Originally Posted by bunny View Post
The answer is B
The question tells about HIV patient and asks about AIDS population
By using triple therapy less HIV people will progress to meet the definition of AIDS syndrome. So the prevalence of AIDS will decrease NOT increase.
I still refuse to accept this answer...

This is quoted from UW (Q Id 1171 [393525])

"Any treatment that prolongs survival but does not cure the disease will increase prevalence due to an increase in the number of afflicted (but still alive) individuals over time."
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