How has medicine changed in the past 20 years? A look at dementia, cancer care and chronic disease

The 21st century began with the first draft of the human genome, and with it, the promise of immense new powers to treat, prevent and cure disease.

In high-income countries like Australia, rates of heart disease were falling, and life expectancy was rising.

Over the past two decades, lots has changed about the factors that affect our health, wellbeing and how long (and well) we live.

So what do we know now that we didn’t then, and how far have we come?

As part of Radio National’s Big 20 series, Dr Norman Swan speaks to three leaders in their field to find out what’s happened in dementia research, cancer care and chronic disease over the last 20 years.

Chronic disease has been getting worse

Dr Norman Swan talks to Professor Chris Murray, director of the Institute of Health Metrics and Evaluation at the University of Washington.

Dr Swan: Take us back to the year 2000. What was the pattern of disease?

Professor Chris Murray: In the year 2000, right before the big push globally on reducing health problems in low income settings, we were pretty much nearing the peak of the HIV epidemic and, particularly in sub-Saharan Africa, we still had a very large number of deaths under age five — 12 million or so a year.

We hadn’t yet had the big efforts to control malaria. And many middle-income countries were right in that transition from a profile of disease burden dominated by infectious diseases and starting that shift towards cancer, heart disease, chronic kidney disease.

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In the high-income world — Australia, Europe, North America — the [disease burden] looked pretty similar. It was already heavily dominated by heart disease and cancer, chronic kidney disease, but there was less obesity back then, there was less diabetes, and we were still back in the heyday of heart disease coming down pretty rapidly.

Dr Swan: What has happened in the two decades since?

Professor Murray: We’ve seen really dramatic progress bringing down child death rates.

In a place like Niger in West Africa, the improvements are just spectacular. You’ve probably halved child death rates in that period … bringing [it] down below the 5 million mark because of antiretrovirals for HIV.

There has been real progress on controlling malaria because of bed-net programs. So just lots of progress racked up, until COVID, on a number of fronts in the low-income world.

Then at the other end of the spectrum in the high-income world, we’ve seen heart disease progress slow, and in some places reverse.

We’ve seen this steady rise of obesity and bringing with it diabetes, high blood sugar, bringing up blood pressure levels in some countries, despite all the therapies that exist for them.

In the middle-income world we’ve seen progress but we’ve seen the rise of ambient air pollution in the last two decades. It’s becoming a bigger and

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How family medicine has changed on P.E.I. since COVID hit

You don’t have to spend much time at Dr. Kristy Newson’s office in Charlottetown to discover COVID-19 has changed the way she and her staff do their jobs. 

For one, the family doctor’s waiting room is completely empty, and the door locked. 

“We try not to fill up our waiting rooms just to avoid patients spreading infections,” said Newson, who also serves as president of the P.E.I. College of Family Physicians. 

“So we ask them to remain in their car until their appointment time. We then call down to them and they come right into the office. And between each patient, we have to disinfect and clean the rooms completely before the next patient can be seen.”

That means she’s not able to see as many patients at her office throughout the day — at least not without extending her hours.

Patients of some family physicians are now being instructed to wait in their vehicles for their appointment, as some waiting rooms like this one are off-limits. (Steve Bruce/CBC)

While Newson said some family physicians are doing just that, she and many others have turned to telephones and web cameras, as a way to squeeze in more patients. 

“Between each [in-person] patient I do some telemedicine appointments, just to give my staff the chance to clean the rooms,” said Newson.  

“We try to triage them over the phone, and if it’s a concern that could be addressed via telemedicine or virtual care, the patient would be offered that style of appointment. If they prefer to see us in person, or if we feel it’s something that needs a physical exam, then we would book them a regular routine visit in our office.”

Doctors seeing just as many patients

According to Health PEI, about 30 per cent of care provided by Island family physicians is now virtual or over the phone. 

Newson maintains with the move to more virtual appointments, there’s been minimal impact on the quality and speed of care family physicians can provide. 

“The perception may be that physicians aren’t seeing as many patients. But truly, it’s more a change in the type of appointments we’re able to offer,” said Newson.

“I wouldn’t say the wait times for urgent or semi-urgent appointments are any longer at this stage. Possibly for non-urgent, annual checkups, those sorts of things, those things have probably been pushed several months down the road.”

Rooms have to be cleaned between appointments, which lowers the number of patients family physicians are able to see in person each day, unless they extend their hours. (Steve Bruce/CBC)

Another change for family physicians since the start of the pandemic — they’ve stopped seeing patients with coughs, fevers and sore throats. 

They’re now directed to the cough and fever clinics in Charlottetown and Summerside. 

“That’s just to prevent the spread of infectious disease at family medicine offices,” said Newson.

“At the cough and fever clinics, they’re able to provide separate exits and entrances for the patients, patients are able to

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How Covid-19 Death-Rate Predictions Have Changed Since March

In March, estimates of how many Americans would die from Covid-19 in the coming months ranged from 81,000 to 2.2 million.

That disparity—which arguably produced as much confusion as insight—prompted one independent data scientist to build his own model in hopes of arriving at a better forecast. (He did.)

Now, as many as 50 different research groups make predictions, but one of the most accurate assembles all of the individual models, calculates the median value and looks no more than four weeks into the future.

The ensemble forecast was founded by the Reich Lab at the University of Massachusetts, Amherst, in collaboration with the Centers for Disease Control and Prevention and is based in part on models previously developed to forecast influenza and other infectious diseases.

In the next four weeks, it predicts the total number of deaths attributed to the new coronavirus will surpass 240,000—adding roughly 17,000 deaths to the current tally.

Such projections help policy makers and health-care officials decide how to manage resources and implement or relax interventions intended to curb the spread of the disease.

“It gives you guideposts,” said Jeffrey Shaman, an infectious-disease modeler at the Mailman School of Public Health at Columbia University. “Are you going in a bad or good direction? Is it under control?”

But even now, the projections of individual models sometimes differ substantially, according to Michael Johansson, co-leader of the CDC’s Covid-19 modeling team. In June, one model predicted that by July, the death toll would top 263,000. Another anticipated that it would be less than 120,000.

By focusing on the median, the ensemble forecast has consistently provided reliable four-week projections. In this case, its projection was 130,558, and the actual figure was 130,089.

“That’s been one of the big advantages,” Dr. Johansson said. “By leveraging all the information from all the model approaches, we get forecasts that are demonstrably robust.”

The Covid-19 Forecast Hub is the central repository for individual forecasts. Those included in the ensemble—currently more than 40—are probabilistic forecasts that look four weeks into the future; provide a point estimate of the expected number of deaths in the period; and include the range within which the actual number will likely fall with prediction intervals of 95% and 50%.

The ranges for each forecast are divided into 23 quantiles. The Hub calculates the median for each quantile, and the ensemble forecast is the median of those values.

“Because of previous work, we know you don’t want to exclude models unless there is a clear reason to do so,” Dr. Johansson said. “They capture different things.”

By confining the forecasts to the short term, changes in policy or public behavior are also less likely to upset the projections.

In contrast, the earlier models tried to predict the number of deaths that would occur months later.


How has your understanding of Covid-19 evolved since March? Join the conversation below.

“Forecasts beyond a relatively short prediction window are not going to be very robust,” Dr. Johansson said. “You

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