Friday 12 March 2010

"Experts"...again!

As mentioned in A slight hitch, Part 2., I attended a "robust" meeting with social services, representatives of the nursing home, mum's Community Psychiatric Nurse and mum's Memory Clinic consultant. Although the meeting didn't go quite as I'd hoped, the outcome was good as the standard of care at the nursing home has improved. She's moving to a better nursing home on Monday 15th March anyway as I'd had enough of the shenanigans with the management that runs the current nursing home.

After the meeting, I had a long chat with mum's Memory Clinic consultant. He explained that I couldn't give mum supplements based on weak evidence e.g. in-vitro studies, animal studies or epidemiological/observational human studies showing associations between "A" & "B". There had to be a sufficient number of large Randomised Controlled Trials (RCTs). Fair enough.

I recently e-mailed the consultant including a couple of links to RCTs showing the positive effect of Vitamin D3 on mood. He e-mailed back saying that the evidence was still weak and he linked me to The Cochrane Collaboration web-site and also to the book Evidence Based Medicine - How to Practice and Teach EBM. I bought the book and took a look at the web-site.

Due to a bug on Amazon, looking inside the above book showed me a completely different book which contained a very interesting piece of information.

The Flecainide Story
Pre-Ventricular Contractions (PVCs) are a fancy name for cardiac arrhythmias. PVCs often result in Ventricular Fibrillation (VF) & death during heart attacks. A crossover study done in the US in the 1980s showed that Flecainide drastically reduced PVCs compared to placebo. Flecainide was approved by the US Food & Drugs Administration (FDA) and prescribed to hundreds of thousands of American heart attack patients (though it never caught on in Europe or Australia).

Unfortunately a later study, the Cardiac Arrhythmia Suppression Trial (CAST) showed that, over an 18 month period, about 12% of patients taking Flecainide died compared to about 5% of patients taking placebo. Oh, whoops! It took quite a while for the bad news to be accepted (as nobody likes bad news especially when it adversely affects drug sales & profits) and for Flecainide to be taken off the market. In the meantime, tens of thousands of Americans died unnecessarily. This is what happens when "experts" focus on one outcome only and ignore the rather more important outcome of all-cause mortality.

Statins reduce cardiac deaths in men under 50 who have had one or more heart attacks. There's a statistically-insignificant reduction in all-cause mortality though as deaths from other causes increase. There's also no statistically-significant all-cause mortality benefit to men over 50 or all women who have had one or more heart attacks, or people who haven't had a heart attack. However, that hasn't stopped statins being prescribed to all and sundry, whether young or old, whether male or female and whether having had a heart attack or not.


The Cochrane Collaboration web-site was most interesting. During my long chat with mum's Memory Clinic consultant, he explained that mum was prescribed a cholinesterase inhibitor (Donepezil a.k.a. Aricept) as there was strong evidence for its benefit. I found Donepezil for dementia due to Alzheimer's disease which indeed confirmed the benefit to patients with Alzheimer's Disease (AD). The thing is, mum doesn't have AD. She has Dementia with Lewy Bodies (DLB). I then found Cholinesterase inhibitors for dementia with Lewy bodies, which concluded:-

"Patients with dementia with Lewy bodies who suffer from behavioural disturbance or psychiatric problems may benefit from rivastigmine if they tolerate it, but the evidence is weak." (emphasis added by me).

There is a condition called Parkinson's Disease Dementia (PDD) which is similar (but not identical) to DLB and I found Cholinesterase inhibitors for Parkinson's disease dementia which concluded:-

"Rivastigmine appears to improve cognition and activities of daily living in patients with PDD."

Rivastigmine is similar (but not identical) to Donepezil. There were no reviews showing the effect of Donepezil on DLB.

So "experts" can prescribe medications based on weak/no evidence but I can't give mum supplements based on weak evidence. I'm not going to e-mail the consultant pointing this out as he may withdraw Donepezil and it does actually have a slight benefit. I'm going to print the above studies and use them to try to persuade mum's new GP (when mum's moved to the new nursing home) to permit me to supply mum with supplements based on my evidence.

I also found Omega 3 fatty acid for the prevention of dementia which stated:-

"Background
Accruing evidence from observational and epidemiological studies suggests an inverse relationship between dietary intake of omega 3 polyunsaturated fatty acid (PUFA) and risk of dementia. Postulated mechanisms that might qualify omega 3 PUFA as an interventional target for the primary prevention of dementia include its anti-atherogenic, anti-inflammatory, anti-oxidant, anti-amyloid and neuroprotective properties.

Main results
There were no randomized trials found in the search that met the selection criteria. Results of two clinical trials are expected in 2008.

Authors' conclusions
There is a growing body of evidence from biological, observational and epidemiological studies that suggests a protective effect of omega 3 PUFA against dementia. However, until data from randomized trials become available for analysis, there is no good evidence to support the use of dietary or supplemental omega 3 PUFA for the prevention of cognitive impairment or dementia."

It's now 2010 and there are still no results from RCTs showing. So, omega-3 PUFAs will not be prescribed despite the evidence from biological, observational and epidemiological studies. Luckily, I keep mum's mini-fridge stocked with smoked salmon and I will request that the new nursing home gives mum a salmon meal twice a week.

2 comments:

Galina L. said...

Hey, Nige,
I tried to ask you about your Mom using the e-mail in your blog, but my e-mail was returned .
Is she alive? I visited my mom for 2 months in order to put her health on a right track. My grandma it still alive with Alzheimer in her assisted living facility at 93.
I hope you will not find my question to be invasive.

Nigel Kinbrum said...

Hi Galina,

My mum was 82 on 4th Jan 2012. I may do a blog post now that I'm feeling less miserable.

Things went a bit wrong last year. Vitamin D didn't improve mum's mental faculties and something else happened that upset me a lot. I've got used to mum's condition and the other matter has been resolved.

Did you delete nospam. from the email address I gave? I added nospam. to it to prevent bots from spamming me.

Cheers, Nige.