Andrew Gunn – (we)blog therefore?

Evidence-based medicine (EBM) means basing medical practice on scientific evidence. Its ascendency is disturbingly recent.

Yogi Berra — the baseball player, not the cartoon bear — identified the commonest complaint about evidence-based medicine many decades ago. “In theory, there is no difference between theory and practice. In practice, there is.”

I practice evidence-based medicine. At least, I recently attempted to. Twice.

The first time was my final encounter of a tiring 50-patient day. I wasn’t his usual GP. He complained about widespread aches and pains, seeking reassurance he wasn’t having a heart attack.

I eased his concerns but recommended he keep an existing appointment with a heart specialist the next day. I wondered aloud if his aches might be caused by his cholesterol-lowering medication, known as statins. Muscle aches are a very common, and still under-recognised, side effect of statins.

I wrote the words, “number needed to treat”, on a piece of paper and handed it to him. I explained the number needed to treat was how many people in his situation needed to take a statin to prevent one heart attack or stroke over, say, the next five years.

If acronyms and statistics make your eyes glaze then the next two paragraphs might be challenging. But you’ll be okay. Trust me, I’m a doctor.

This is the key concept: The number needed to treat (NNT) is the inverse of the absolute risk reduction (ARR), which is of course totally different to the relative risk reduction (RRR).

If, for instance, a drug reduces the incidence of stroke from 2% to 1%, then the RRR is 50% (because 1% is half of 2%), the ARR is 1% (because 2% minus 1% equals 1%) and the NNT is 100 (because the inverse of 1% or 1/100 is 100).

ARR is critically important. In contrast, RRR is deceptive drivel found in advertisements, media releases, sloppy medical articles, and the occasional National Prescribing Service handout. You generally hear about RRRs.

But I digress. I also briefly explained the concept of number needed to harm (NNH). Assuming the magnitudes of harm and benefit are comparable, then the NNT of any treatment must be less than its NNH. If the NNT is greater than the NNH, then the treatment will harm more people than it helps.

I suggested my patient ask the cardiologist for his statin’s NNT. He was taking it for primary prevention, having had no previous heart attacks or strokes. In his circumstances, the NNT was very likely to be over 50. In other words, there was less than one chance in 50 the tablet would do him any good within the next few years and it might well be harming him.

I didn’t get an answer from the cardiologist about the NNT. Perhaps this was because imaging was ordered to investigate the aches and pains. It turned out the statin wasn’t the problem. The man’s pain was from multiple bony secondaries of a previously undiagnosed cancer.

During my second recent flirtation with evidence-based medicine, I avoided the same mistake. I already knew this patient had cancer.

She was worried because her oncologist wanted to start chemotherapy. I didn’t know the statistics to give adequate counsel on this, so I gave her a letter. In it, I asked the oncologist to discuss the NNT and NNH of chemotherapy with her.

Yesterday, I saw her again. She looked much more relaxed. She said the oncologist had decided against chemo.

Every prescription or procedure should be dictated by its NNT and NNH yet doctors mostly work without knowing them. Try asking for the NNT and NNH of your treatments, then sit back and observe the response!

In the future, doctors should be able to rattle off these figures for any treatment and be prepared for the reply, “Huh? There’s only one chance in fifty this will help me, there’s some chance it’ll harm me and on top of that, it’s expensive? Forget it, doc!”

Hopefully Yogi Berra was right. “The future ain’t what it used to be.”

(An earlier version of this article “Evidence in Practice” was published 7 Oct 2011 by Australian Doctor www.australiandoctor.com.au)

Just between you and me, I may have killed my father 14 years ago.

He was in his 70s when he mentioned he’d developed a gum boil. His cheek was more swollen than his gum so I suggested he see a real doctor. His GP then referred him to an ENT surgeon. The surgeon took a biopsy and ordered a chest X-ray.

While waiting for follow-up, my mother asked me to check the X-ray. She seemed a bit concerned. It was soon apparent why.

The lung fields looked far from normal. The report, which my mother must have read, said there were multiple pulmonary metastases.

I broke the news to my father, who was visibly deflated. I told him cancer was an unpredictable disease and he’d beaten it before. He agreed but said this time felt different. As usual, he was right.

A couple of days later I went with him to see the surgeon. The surgeon pulled out the biopsy report and embarked on a spiel of how resection would require the loss of an eye and a good part of the face.

I waited for a lull to ask the surgeon if he’d seen the chest X-ray. A flicker of alarm passed across his face. “No,” he admitted as he reached for the films.

My father was a bit perturbed when the X-ray instantly changed his treatment options from curative to palliative — but at least he now knew that the disappointing X-ray result had prevented the excision of half his face.

Eight months later, my father was still battling on against the odds. My mother rang one night to say he was particularly unsettled. I suggested an increase in his dose of morphine.

A few hours later, I was plucked from an RACGP pre-exam course to take a phone call. My father had suddenly died.

I don’t know whether the extra morphine killed him but it’s certainly possible. Luckily, we are sometimes allowed to kill people if our intent is to reduce their suffering — provided, that is, we don’t intend to reduce a patient’s suffering by killing them. In some jurisdictions, that’s literally a hanging offence, even if they do want to die and we don’t want to.

Patients are often more realistic than ethicists or politicians about death. Just a few hours ago during a home visit, a patient with an inoperable 8.5cm liver secondary discussed euthanasia with me. The dying get tired of living more readily than the living get tired of being control freaks.

Last year, a Greek GP friend spied a man at a café who was chain smoking, shirtless and sporting an anti-angina patch. The patch was suspended in mid-air by a thick Mediterranean coat of body hair.

The hairs had infused sufficient nitro-glycerine to explode if a match strayed nearby but the man’s blood concentration was probably zero. My friend couldn’t resist striking up a conversation laced with health advice.

The man’s rejoinder was illuminative. “Many die but none return. It can’t be that bad.”

Simon McKeon has just been named the Australian of the Year. I hadn’t heard of him, which is a point in his favour.

McKeon is an investment banker specialising in mergers and acquisitions. Whatever his day job’s ethics, his noblesse oblige has prompted significant involvement in charities like the Christian aid-organisation, World Vision.

World Vision shrewdly promotes the idea that donors will sponsor specific individuals. This is known to increase contributions. As Mother Theresa said, “If I look at the mass I will never act. If I look at the one, I will.” Stalin was more succinct: “One death is a tragedy; a million is a statistic.”

Charitable work is a Good Thing, even if Ralston Saul thinks that increased emphasis on charity and volunteering indicates a weakening of democracy and citizenship. Taxation—not charity—pays for civilisation. From each according to their ability, to each according to their need, and all that stuff.
A Brazilian archbishop once said, “When I give food to the poor, they call me a saint. When I ask why the poor have no food, they call me a communist.”

Saints are generally unthreatening and sometimes help to maintain the status quo. They get more accolades than communists.

McKeon sounds like a decent guy, maybe even a saint, but this year somebody else deserved the Annual Aussie Award. I’m talking about the unsaintly bloke who proved that just because you’re paranoid doesn’t mean they aren’t out to get you. Yay for Julian Assange of WikiLeaks. Perhaps a Nobel Peace Prize would be consolation.

A character in Kurt Vonnegut’s novels called mirrors “leaks” because he thought they leaked information from another universe. WikiLeaks and its mirrored sites give us information from that other universe. It’s a strange place.

Like many other Australians, I thought the current war in Iraq was a stupid idea even before it started. Unfortunately, our pre-WikiLeaks leaders were able to justify it with a pack of lies about Saddam Hussein’s weapons of mass destruction. It seems democracy does not imply a right to know what your government is doing in your name. The result has been a statistic of deaths.

The persecution of WikiLeaks has highlighted certain 21st century realities. For instance, major credit organisations will handle the Ku Klux Klan’s money but not WikiLeaks’. Money is power.
Come to think of it, Mao said power came from the barrel of a gun and Francis Bacon thought knowledge is power. I prefer Bacon. Assange probably does too.

If you control knowledge then you control the people with guns and money. That’s why Egypt—currently in watch-this-space mode—cut off the internet.

Assange missed out on Aussie of the Year but a magazine did declare him Un-Australian of the Year for “dobbing”. This was inane. It is not dobbing to publicise damning information about someone who is incredibly powerful and prone to extreme violence. It’s suicide.

The mag’s second place getter as Un-Australian of the Year, for not moderating the weather, was God. Good call.

(First published by Australian Doctor online 4 Feb 2011 http://www.australiandoctor.com.au/articles/98/0c06ec98.asp? )

6 Feb 2011

Okay, I just created this account and there’s nothing much here yet.

You’ll find more at http://www.andrewgunn.com (yup, I’m “drandrewgunn” on gmail, twitter, wordpress and everything else BUT I’ve got the andrewgunn domain name <insert victory dance>).

Simon McKeon has just been named the Australian of the Year. I hadn’t heard of him, which is a point in his favour.

McKeon is an investment banker specialising in mergers and acquisitions. Whatever his day job’s ethics, his noblesse oblige has prompted significant involvement in charities such as the Christian aid organisation World Vision.

World Vision shrewdly promotes the idea that donors will sponsor specific individuals. This is known to increase contributions. As Mother Theresa said: “If I look at the mass I will never act. If I look at the one, I will.” Stalin was more succinct: “One death is a tragedy; a million is a statistic.”

Charitable work is a Good Thing, even if Ralston Saul thinks that increased emphasis on charity and volunteering indicates a weakening of democracy and citizenship. Taxation — not charity — pays for civilisation. From each according to their ability, to each according to their need, and all that stuff.

A Brazilian archbishop once said: “When I give food to the poor, they call me a saint. When I ask why the poor have no food, they call me a communist.”

Saints are generally unthreatening and sometimes help to maintain the status quo. They get more accolades than communists.

McKeon sounds like a decent guy, maybe even a saint, but this year somebody else deserved the Annual Aussie Award. I’m talking about the unsaintly bloke who proved that just because you’re paranoid doesn’t mean they aren’t out to get you. Yay for Julian Assange of WikiLeaks. Perhaps a Nobel Peace Prize would be consolation.

A character in Kurt Vonnegut’s novels called mirrors “leaks” because he thought they leaked information from another universe. WikiLeaks and its mirrored sites give us information from that other universe. It’s a strange place.

Like many other Australians, I thought the current war in Iraq was a stupid idea even before it started. Unfortunately, our pre-WikiLeaks leaders were able to justify it with a pack of lies about Saddam Hussein’s weapons of mass destruction. It seems democracy does not imply a right to know what your government is doing in your name. The result has been a statistic of deaths.

The persecution of WikiLeaks has highlighted certain 21st century realities. For instance, major credit organisations will handle the Ku Klux Klan’s money but not WikiLeaks’. Money is power.

Come to think of it, Mao said power came from the barrel of a gun and Francis Bacon thought knowledge is power. I prefer Bacon. Assange probably does too.

If you control knowledge then you control the people with guns and money. That’s why Egypt — currently in watch-this-space mode — cut off the internet.

Assange missed out on Aussie of the Year but a magazine did declare him Un-Australian of the Year for “dobbing”. This was inane. It is not dobbing to publicise damning information about someone who is incredibly powerful and prone to extreme violence. It’s suicide.

Second place as Un-Australian of the Year, for not moderating the weather, went to God. Good call.

IT rained for weeks and then got wetter in January. Climate change, anyone?

I was in the Sunshine Coast hinterland. Rain was torrential but minor house repairs were needed to keep snakes out.

A teenage son and I left for a hardware store, a one-hour round trip. Creeks were swollen but we got there.

When returning, cars slowed ahead of us. A sign said, ‘Saltwater over road’. The water looked shallow and I figured driving slowly meant salt would barely touch the car. A speeding bus in the opposite lane disproved that theory.

Rain kept bucketing down. Out of town, I pulled over so a large van would pass. They could be my flood marker. Cars are occasionally lost crossing the local creeks.

The van was moving quickly but I kept up. Its tail lights were more visible than the road.

The van braked at a long section of flooded road. It crept forward into the water but then stopped. I realised that instead of fondling a length of rope in the hardware store, I should have bought it.

The van then accelerated and was soon on its way. I decided to take the plunge. Momentum would be my friend.

Apparently you need to go above 60kmh to hydroplane. I was not going that fast but in the most treacherous and rapid-flowing section my tyres created the second-biggest plume of water I’ve ever seen. Man, I scared the bejesus out of that creek.

The next day, I got smarter and checked the tide times before leaving for Brisbane. We were safely home before the highway closed.

A day later, I drove to work in outer suburbia. My usual route was impassable but a short detour did the trick.

Half-a-dozen patients into the day, I was told the clinic would close. Nearby creeks were rising and staff could be trapped for days. Toowoomba’s unbelievable flash flood a day earlier didn’t help anxiety levels.

I saw a couple more patients and shut up shop. I was preparing to leave when a journalist called. I explained I was rushed and asked why he had rung. He wanted flood news.

Unfortunately for his story, I wasn’t carrying a patient through flood water. I similarly disappointed another journalist a day later.

On the way home, I stopped at a supermarket. The checkout chick congratulated me on the day’s best panic buy.

As Brisbane flooded, I sat safely at home feeling vaguely fraudulent. The internet was alive with images of flood victims I could not assist. Most lived in Brazil but many were just kilometres away. I could not even get to my hostel patients.

I view most politicians dimly but several shone during the floods. In recent decades, Western leaders have encouraged the strong to help themselves. This disaster has made our leaders encourage the strong to help the weak. Building human communities, instead of destroying them for a dollar, is a lovely change. Let us hope it lasts.

WORK can be a health hazard. Theodore Rothonis, a Sydney GP, would attest to that. The patient who stabbed him has just been tried (he was found not guilty on mental health grounds but will be detained in a prison hospital until authorities deem he no longer poses a risk to the public).

Recent tragedies confirm that working in mines is also dangerous. So is clearing mines, when it is done by peasants or Hurt Locker GIs rather than Princess Di. The most dangerous jobs, however, are illegal. Street prostitutes and drug dealers often meet untimely ends. General practice has its hazards but there are more GP suicides than murders.

A colleague recently asked if I would accept another patient. The man had disclosed a fantasy that involved slicing his doctor’s flesh with a carving knife. Last Tuesday, I met my new patient and he was as nice as pie. A forced stint in hospital and the knowledge that you’re running out of treating doctors can improve attitude problems.

On Wednesday, I visited a hostel. One resident has a stream of interesting ideas. His latest is to get bullet-shaped mouldings clamped onto cars so they can be shot through tunnels under cities.

Even by my jaded standards, when I saw him this week he seemed dangerously agitated. I suddenly understood why he gets weekly ECT. I left as the uniformed cavalry arrived to get him to hospital.

Workplaces often have duress alarms but I have never used one. Anyway, I suspect blood-curdling screams are more effective.

I was once attacked by a patient when an alarm was within reach. I was too busy to consider activating it. I lost a shirt button when without warning an intellectually impaired man grabbed my neck. His carers later commented that his mother regards him as “80% intellectually disabled and 20% evil”.

At an Aboriginal medical service, I once discovered a large kitchen knife stashed among the paperwork. The nurse explained that it was for her protection. The knife did not make me feel safer but each to their own. I did not want her job.

Seventeen years in a clinic for homeless youth provides a few more anecdotes. For instance, I have twice wrestled bloodied broken glass from patients who were busily gouging their forearms in front of me. I guess this seemed less hassle than suturing them up.

I have also had a pistol waved at me followed by the explanation that it was only a replica. On another occasion, a patient suddenly lunged towards my abdomen with a kitchen knife. I jumped back, which prompted an exasperated, “Jesus Doc, as if I’d stab you! I’ve known you for ages!”

A couple of years ago, I found myself physically intervening in a fight. One of my patients was on the ground being kicked in the head.

I rang Medicare that night. I figured my actions had saved the health system a pile of cash so I asked about an item number for prevention of acquired brain injuries.

I waited in nervous anticipation and could hear the Medicare woman banging her keyboard in the background. Her answer? “The computer says no.”

EARLIER today, I needed to buy a stapler. It took longer than expected because the shelves contained dozens of alternatives. There was too much choice.

Our mixed communities even give us a choice of religion. A favourite homeless patient once told me that if you are going to have an imaginary friend, you may as well have lots of them. He chose a polytheistic Eastern religion because he needed all the friends he could get.

Another of my favourite patients is a vegan, a choice he made decades ago. Last month, I broke bad news to him. He had been getting headaches and a CT scan showed brain cancer. My patient — a thinker and one-time associate of Bertrand Russell — remains disappointed. His brain is important to him.

My father felt the same way about his own brain. The same news created similar disappointment. To my surprise, my mother’s initial reaction was more complex. Apparently multiple cerebral secondaries did at least explain some recent behaviour changes. I believe my mother just meant that my normally kind and placid father had become an unpredictable grump — but occasionally more dramatic behaviour changes make the news.

In a well-publicised case, a paedophile had a brain scan the day before sentencing. A frontal lobe tumour was discovered and its resection cured his aberrant behaviour. When the tumour recurred he relapsed.

It seems common for us to behave as if smoking, eating junk food and, of course, poverty are all choices. In some situations, however, it seems paedophilia is not.

The neuroscience of choice is surprisingly little-known … or perhaps not surprisingly little-known. Life is difficult enough without trying to deal with reality.

Libet’s classic neurological experiments on choice were conducted decades ago. These showed a pretty obvious result. If people decide to move their wrists then, a fraction of a second later, their wrists will move.

The freaky bit was that the brain’s motor centres causing the movement would spike on an EEG about half a second before the conscious decision was made to move. This finding has been reproduced many times and it seems that the requisite motor cogwheels are in motion before we make the apparently free choice that NOW is the time we want to use them.

More recent experiments further suggest that conscious choices describe actions but do not control them. For instance, in one study, participants were asked to freely decide whether they wanted to press a button with their left or right hand. High-tech brain scanners could then accurately predict, many seconds before any conscious decision was made, which hand subjects would choose.

These research findings are more or less supportive of what Western philosophers term epiphenomenalism. Lay people usually term it bollocks because it is bizarre to think conscious decisions do not impact on behaviour.

Smarter people than me are busily constructing Ptolemy’s epicycles to explain away the research. And I’m sorry if you didn’t enjoy this article but it had to be written. I had no choice.

DEATH. Certificates. Two words that are unpleasant individually and downright ugly together. But death certificates are eventually written for us all, because we never save lives, we just delay deaths.

I’ve learnt a thing or two about death over the years. For instance, I now know what it means if gentle rotation of an oropharyngeal airway draws dark blood — particularly if the unconscious mouth seems oddly unrelaxed.

This is pathognomonic for ‘do not attempt resuscitation because your home visit patient is already in rigor mortis’.

In addition, I know you shouldn’t decree to relatives that Gran has departed until you’ve witnessed more than a minute of asystolic arrest. And, if she unexpectedly and briefly arises from the dead before irreversibly shuffling off this mortal coil, it is appropriate to diagnose her bitter complaints of chest pain as angina rather than reflecting on that cracking noise heard during your earlier precordial thump.

I’ve also picked up a thing or two about certificates. To be blunt, they are often rubbish. (Okay, that’s only one thing about certificates but let’s pretend it’s two.)

A few weeks back, I received a 3am call from the police. An elderly patient had unexpectedly died at home and the usual quick decision was needed. Could I write a death certificate or was a coroner required?

I had a quick talk to the police (“no suspicious circumstances”), the paramedics (“a run of VF”) and the widow (appropriately shocked and already articulating what I often tell patients, namely that a quick death is often better for the victim but worse for the survivors).

I agreed to write the certificate. Ischaemic heart disease had claimed another victim.

This led me to reflect on a past incident. One week after finishing my intern year, I was promoted to medical superintendent and sent bush.

A local resident suddenly died in a pub and, needless to say, resuscitation proved futile. The ambos asked if I’d write a death certificate or whether the government medical officer should do an autopsy.

I took the easy option. Why write a speculative certificate if an experienced doctor could do an autopsy?

The next morning, I rocked up to work and was surprised to be told a body was in the morgue. The dreadful truth dawned. I wasn’t just the town’s medical superintendent; I was also the region’s government medical officer.

The local police sergeant twigged that I hadn’t expected to do the autopsy. He obligingly suggested that most patients die from “my old car deal in Far Cushion”. I made a mental note of this and proceeded to remove the corpse’s heart. This was partly to pretend I was doing a proper job and partly to placate the salivating wardie doubling as pathology assistant.

After appropriate examination of lifeless innards, I confiscated the circular saw from the disappointed wardie. He still wanted to remove the brain but I was ready to decree the cause of death. It was, as the sergeant had anticipated, myocardial infarction.

This is, of course, the problem with all those murder investigation TV shows. In real life, Constable Plod discovers a body and rings the local GP. Then, before the brilliant forensic team gets the merest whiff of an intriguing case, one of our colleagues signs off on my old car deal.