2. To provide peace of mind to Ariels head

This is a perfectly good reason to do the test.

One question that gets forgotten in medicine is this:

“What do you think it could be?”

I wasn’t taught to ask this in medical school, it was a bit of wisdom from a skilled clinician. The significance is that if I don’t ask that question, and treat that concern I might get the diagnosis 100% correct, and the treatment 100% correct, but have failed to address the real concern that brought the patient to my door.

Hi A.L.

With the proviso that your ALT was elevated out of range pre treatment (a handful of patients with a significant VL have normal looking LFTs at baseline) then ALT elevation is a reliable marker for relapse. Elevations of LFTs for no obvious reason are the usual reason doctors look for HCV.

So, at SVR24, if your ALT is normal, and you’re not feeling any of the “usual suspect pre-treatment symptoms” then HCV RNA PCR is largely academic – we are not going to find anything. My reason for ordering it would be to remove patient doubt/anxiety, rather than because it’s strictly needed and I’m not already sure what the result is.

Some patients like my direct style, some find it blunt but consider this:

Life is a terminal disease, and sexually transmitted at that!

My mum’s take on it goes like:

Life is not a trial run

But this remains my favourite:

I shall pass this way but once;
any good that I can do or any kindness I can show to any human being;
let me do it now.
Let me not defer nor neglect it,
for I shall not pass this way again.

– Etienne de Grellet

Hazel found this…

I don’t understand the bit about the little grey bars. What is a ‘confidence rate’? Can someone who understands statistics please explain?

I could point you at this https://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval but the formulas might make your eyes bleed so let’s work through it. It’s actually pretty easy to understand.

Say we have a coin and we toss it once. It comes up heads. We now have 100% (1/1) heads, but it could just as easily have been 100% tails. It was impossible to get the expected 50:50 result with a single toss, but even with 2 tosses it is 1:4 of being 2 heads, 1:2 of being a head and a tail, and 1:4 of being two tails. With 3 tosses the chances of 3 heads are 1:8, 4 tosses 1:16, 5 tosses 1:32 so you can see that the more we toss the coin the less likely we are to get an “all heads” rubbish result.

If you go to this page: http://statpages.info/confint.html you can put in 1 for x and 1 for N and get the confidence interval on our single coin toss which is 0.0250 – 1.000 (2.5% to 100%). You can change the values for x (say heads) and N (say tosses) and see what happens.

Now say we toss it 3 times and get 2/3 – 66% heads. The confidence interval is 0.094 – 0.9916 (9.4% to 99.16%)

Now say we toss it 30 times and get 20/30 – still 66% heads. The confidence interval is 0.4719 – 0.8271 (47.19% – 82.71%)

See how the confidence interval gets narrower the more tests we do? I kind of makes sense that the more we test this, the closer we are going to get to the right answer.

Now say we toss it 300 times and get 200/300. Now we have tossed it so many times that random chance starts to evaporate because we have had lots of tries. The confidence interval is now 0.6102 – 0.7198 – narrower again, but….

This interval does not include 0.5 aka 50% aka 50:50 so we can conclude that the coin is loaded.

So in short the more results we have the more confident we are that the value is correct and the confidence interval tells us how much higher or lower the real result could reasonably be if we do an infinite number of trials.

What’s “reasonable”?

Reasonable in this case is a mathematical definition because confidence intervals exist at different levels. We have been looking at the 95% confidence interval level that says – with mathematical precision – that 95% of the time, the results will fall within this range.