Help with my pre-hypertension/pre-high blood pressure

[fls]

Statins are just about useless, with 200 patient years of treatment needed for one year of one patient's life extension. And weight loss alone is no help.

Where are you getting this number?

Linda

 

[casebro]

Where are you getting this number?

Linda

Using the 4S study results, simple enough to draw your own graph:

Draw a box. Make two diagonal lines, low on the page. Stating at the low left corner, Higher to the right. One ending at 5%, one at 7.5%. Extend the lines out of the box. Scale the bottom in 1/5 intervals.

The bottom scale represents 5 years. The 5% is how many patients on Statins died in 5 years. The 7.5% is how many controls died. A 1/3 improvement. So far, this all jibes with what the 4S and all other studies show, right?

Interpretation: Graphs are typically used to forecast into the future. So lets.

Extend a horizontal line out to the right from the 7.5% line. Note how far the 5% line extends before it meets the horizontal line. That shows how long the 5-percenters have before they reach the 7.5% life span. About two years max. It is a triangle, so the average is about one year. With me so far?

Now the 200 years of treatment part:

2.5% is one in 40. The studies are all five years duration. So 40 patients for 5 years =200. That's 200 patient years of treatment for the ONE year of life extension, for ONE patient. Average.

Th 4S study was extended for 5 more years, but the lines are straight. Odd, no curves, nature hates a straight line. Well actually, at the 5 year mark they put their controls on Statins too, combining all stats. I believe it should have been considered two 5 year studies, but is claimed to be one 10 year study. No difference in my interpretation, as a 10 year plan it still works out to 1:200. Just about all Statin studies show the same % improvement, over the same time frame. The straight line means the data is scalable, for ever into the future.

I would think that by now the Farmingham Study would have some bigger, longer numbers. But I haven't found any. The FS ought to be able to show the two groups with potential life span differences, since it has been going on for ummm 60 years? No soap, no loooong term data published. When all we, as patients, want is longer lives, since the overall death rate is still ONE.

PM me if my graph directions are not clear, I can send a jpeg. I lack a photo host to use as a link. I have a limited income, disabled as I am by CAD.

ETA: Maybe this is easier logic:

The 4S study was about 5,000 patients. For 5 years. Thats 25,000 patient years of treatment. About 250 died in each group. One third lower = 80 people who lived an average of one year longer. 80 years vs 25,000=300 years of treatment per year of extension. Again, scalable.

 

[fls]

The two lines already represent an average. Differences between the lines apply to all members of the group. This means that the 2.5 year difference between the two lines when 7.5% have died (or more appropriately, the 1.67 year difference between the two lines when 5% have died) applies to everyone. That is, each person that is treated has their life extended by that amount. You only need to treat one person to extend their life by that amount (and of course, the absolute amount depends upon the time over which you are measuring the difference).

The number-needed-to-treat is 200 using those numbers. That is, you would need to treat 200 people for one year to save one life. But since the life expectancy is several decades, it's as though those decades of life are re-distributed over those 200 people, giving each of them an additional few months.

Linda

 

[casebro]

No. the raw numbers are, approximately

280 died in the control group of 5,000.

200 dies in the Statin group of 5,000.

Thats 80 lives extended. After 25,000 patient years of treatment.

Those 80 people are not immortal. They will die almost as soon, either from heart disease, cancer, or stroke. In about two years, by my graph.

Where do you get the 'several decades'?

No averages. Just raw numbers. Now make your own chart.

Or ask somebody here that is better at statistics to make one for us.

 

[fls]

No. the raw numbers are, approximately

280 died in the control group of 5,000.

200 dies in the Statin group of 5,000.

Thats 80 lives extended. After 25,000 patient years of treatment.

You are counting each life as though it represents a year, though. That is clearly not a valid assumption. If you wish to report the number as number needed to treat to extend one life one year, in addition to number of lives saved, you need to know the number of years remaining for those lives (i.e. life expectancy).

Those 80 people are not immortal. They will die almost as soon, either from heart disease, cancer, or stroke. In about two years, by my graph.

Where do you get the 'several decades'?

There is a formula for calculating life expectancy from death rates (LE=1/m, m=1/t*ln(proportion of people surviving at time t)). This is a simplified version, but hopefully it gives you the idea.

No averages. Just raw numbers. Now make your own chart.

Or ask somebody here that is better at statistics to make one for us.

I don't think you'll like the results any better.

Linda

 

[blutoski]

My brother lost 30 pounds, started bicycling to work 150 miles per week. Lots od endurance. His BP went up. His doctor says "Of course, exercise will raise your BP. Here's some pills."

I think you know how much we hate anecdotes.

And what the MD said doesn't make any sense or was misunderstood. There is a huge body of evidence that supports the claim that while blood pressure increases during exercise (obviously), that cardiovascular fitness (the result of exercise) is strongly associated with low resting bp, all things being equal.

My colleage who runs the blood clinic at Canadian Blood Services and I were discussing this the other day: a disproportionate number of athletes cannot donate blood because their blood pressure is too low. They try to identify ways to send targetted marketing to candidate demographics, and unfortunately, athletes have a high rate of disqualification.

This is not to say that everybody with a blood pressure problem will benefit by going out and running circles around the block... many people have other medical contraindicators with risks that outweigh benefits. Seniors at an advanced age may not live long enough to see benefits. &c.

If the causes of your hypertension are largely genetic, and if the family history is that serious, then you really need to work on a management plan with an MD, rather than taking stabs in the dark on the intertubes.

 

[casebro]

280 people died in the control group.

People are dying in the treatment group. They are not immortal. 200 died in 5 years. How long before 80 more die?

Two years.

Average extra life span of those 80? One year.

Years of treatment, 25,000. For 80 folks to live an average one year longer.


Oh sure, the average life span of the groups as a whole is 75 years, decades to go! But we are not concerned with the average life span of the 90-some-odd percent who haven't died yet. We want to know how much extra those 80 are going to life.

Or, apply your math to two groups of 55 year olds. One group has 95% surviving after 5 years, the other group has 92.5%. The difference is the crux. I wonder why nobody has ever published that number? Please do.

ETA, WHOOPS, better wait. Those are heart attack rates. To do that math, you'll want the overall death rates of the two groups. Easily available on Google. Look for '4S'. I don't care what I die of, only whether something hlps me live longer.

How many patient years of treatment are needed for each one year of difference? Note that 60% of us do NOT die of heart disease. That's 3,000 treated for 20 years- for nothing! 60,000 treatment years for nothing. Statins don't make that 60% live any longer.

 

[fls]

280 people died in the control group.

People are dying in the treatment group. They are not immortal. 200 died in 5 years. How long before 80 more die?

Two years.

Average extra life span of those 80? One year.

Years of treatment, 25,000. For 80 folks to live an average one year longer.

Oh sure, the average life span of the groups as a whole is 75 years, decades to go! But we are not concerned with the average life span of the 90-some-odd percent who haven't died yet. We want to know how much extra those 80 are going to life.

To measure the life years gained, you would follow each group until all had died and calculate the area between the two survival curves. What you are effectively doing is truncating those curves at five years (as though everyone died at the end of the study), so that the only life years gained were during the 5-year course of the study. What happens in real life (assuming no additional treatment is given at the end of the study) is that the curves continue to diverge or run parallel and then eventually begin to converge as death rates in both groups increase due to other disease. Sometimes we have complete information. For conditions with a high mortality rate, such as some kinds of cancer, we can follow the groups until everyone is dead. But the reason that we don't usually present outcomes as years of life gained is because our information is usually far too incomplete, as it is in this case.

Sometimes we attempt to extend the survival curves in order to estimate this value using actuarial data. For example, here is a study estimating life years gained from the 4S study assuming the treatment was stopped at the end of the study (i.e. it answers the question you are attempting to answer). Gain in life expectancy from the trial was 0.240 per person for five years (0.054 for one year) of simvastatin treatment. This works out to a NNT of 4 over five years to extend one life by one year or NNT of 19 over one year to extend one life by one year (the numbers are 3 and 15 if you don't consider unrelated causes of death).

Or, apply your math to two groups of 55 year olds. One group has 95% surviving after 5 years, the other group has 92.5%. The difference is the crux. I wonder why nobody has ever published that number? Please do.

I don't understand what point you are making here.

How many patient years of treatment are needed for each one year of difference? Note that 60% of us do NOT die of heart disease. That's 3,000 treated for 20 years- for nothing! 60,000 treatment years for nothing. Statins don't make that 60% live any longer.

While 60% may not die of heart disease because they die of something else first, we are all at risk of dying from heart disease if nothing else intervenes.

Linda

 

[casebro]

So, in round numbers, starting Statins in our fifties, enables us to average one year longer. So my figure for life extension was right, though my NNT may be wrong.

And, to swing this subject back towards the OP- If that is what happens if we lower a major risk factor of death by 1/3, then I suppose treatment of HPT is just about as effective? Stay light-headed, suffer from optical migraines for 20 more years, with swollen ankles, and live one extra year?

Is that what patients expect ?

 

[fls]

So, in round numbers, starting Statins in our fifties, enables us to average one year longer. So my figure for life extension was right, though my NNT may be wrong.

At age 50, life expectancy is an additional 30.5 years (US, 2003 life tables), so you would expect to extend your life 1.6 years. And death isn't the only outcome of interest. We are also interested in preventing heart attacks and angina, so that in addition to extending life, you remain functionally independent for more of those years.

And, to swing this subject back towards the OP- If that is what happens if we lower a major risk factor of death by 1/3, then I suppose treatment of HPT is just about as effective? Stay light-headed, suffer from optical migraines for 20 more years, with swollen ankles, and live one extra year?

Is that what patients expect ?

That shouldn't be what patients expect. We have a lot of choices in anti-hypertensives, so they should expect to find something tolerable when it comes to side-effects. We really shouldn't base decisions on unusual or rare situations (with respect to optical migraines - I assume you are referring to yourself or someone you know). And in addition to extending life by years, preventing strokes would mean that the quality of life is extended as well.

Linda

 

[Speedskater]

This thread has too many TLA's.
I feel like I need a secret decoder ring just to follow it!





TLA = Three Letter Acronym