It's not just the times that are a changin'. So is the pattern of diseasesthat kill and disable people all over the world.
Today, the principal perpetrators of illness and death on our planetare the infectious diseases. But a quarter-century from now, in 2020,non-communicable ailments, notably ischemic heart disease andunipolar depression, will hold top title to global mortality andmorbidity.
Today's issue of Science highlights such forecasts as these in a papertitled "Evidence-based health policy: Lessons learned from the globalburden of disease study.
That study reports the fact-finding efforts over the past five years ofmore than 100 scientists around the world, coordinated and compiledby the Harvard School of Public Health. Its first author, ChristopherMurray, directs the Burden of Disease Unit at Harvard's Center forPopulation and Development.
"It suddenly dawned on the World Bank five years ago," Murray toldBioWorld Today, "that the World Health Organization [WHO]couldn't provide an overview to the Bank, worldwide, by region, oreven by country, of what the major health problems were in a givenplace. So the bank, based in Washington, and WHO, in Geneva,asked Harvard if such a study could be done. It was supposed to takeone year; it took five."
To begin with, Murray's unit examined health data worldwide from1950 to 1991. "We looked," he explained, "at how much of their age-specific mortality rates from different causes can be explained bymajor socio-economic variables, namely income, education,technology changes and tobacco.
"These four variables," Murray continued, "do rather well inexplaining past trends for many diseases, particularly cardiovascularones and cancer. The one risk factor you can't ignore," he added, "isthe epidemic of tobacco-related diseases. By 2020," he observed,"tobacco is expected to kill more people than any single disease,surpassing even the HIV epidemic."
As the world trend continues to shift from developing countries withmany children and few surviving old people to a more evenlydistributed age population, "the age-specific death and disability ratesfrom infectious diseases and maternal and perinatal conditions andmalnutrition all decline very quickly," Murray said.
"The surprise," he went on, "is that non-communicable-disease deathrates also decline. Some people who think about the affluent,sedentary, high-fat lifestyle that we have might expect these rates togo up. But they don't; they go down."
By and large, he observed, pharmaceutical and biotech companiesdeveloping disease-targeting products "have very limited andextremely simplistic market-forecasting ability. The two or threecompanies that have heard about our report were sort offlabbergasted that this work has been done."
Pharmacist John North is director of international relations for EliLilly & Co., in Indianapolis. He told BioWorld Today: "Murray'sstudy certainly is a road map to the year 2020. It is broken down bythe different regions of the world. I think it's the most comprehensivelook at disease that I have seen in some time."
Asked if it would be of practical use to Lilly, North replied: "Yes,very much so. Certainly for a company like Lilly, which has a strongcentral nervous system product pipeline, and the world's leading anti-depressant in Prozac.
"Overall," North noted, "In the year 2020, as measured by Murray'sstudy, depression will be the number-two burden of disease for allnations, and number one cause of disability in the developing world.If we look at where Lilly's research direction is going and read datalike this, maybe it reconfirms that in ordering our priorities we'relooking in the right areas, which will have important consequencesfor the world's population."
Murray mentioned a datum not in his Science paper: "Right now,about 15 percent of global health expenditure is in the developingworld _ Asia, Latin America, the Middle-East Crescent, Africa. Thatisn't enough so far to get a lot of attention, though increasingly, interms of product marketing, it is." The globalization of Lilly andMerck and some of these other pharmaceutical firms in the last fiveyears," he added, "is remarkable. They didn't have all these countriesto consider; now they do.
"It's not just rich consumers in those countries," he pointed out. "Thegovernments are becoming richer, and they can therefore purchaseinterventions that may address health problems strictly for the poor."
In this vein, though, he cautioned: Even for health conditions that aresimilar, for instance, managing acute myocardial infarction, thestrategies in Latin America or Asia are going to have to be more cost-effective. There needs to be a lot more effort at products tailored to amiddle-income environment, which can't readily spend $50,000 for aprocedure, but can spend $5,000 or $10,000."
Murray put his finger on one potential weakness of marketprojections by pharmaceutical and biotech product managers: "Whenyou forecast one disease condition in isolation, time and again in ourexperience a single disease gets the story wrong or exaggerateswhatever the trend is. After all, you only die once."
He also noted one imponderable in any forecasting, including hisown: "When you forecast, you are sort of second-guessing humannature. And our assumption here is that past investment in newtechnology will continue. That's built in to the socio-economic modelof the forecast.
"In other words," Murray went on, "if we were suddenly to stopinvesting in new drugs, this forecast might not be true. One has tothink carefully about what I would call possible but low-probabilityscenarios: For instance, a new AIDS virus or outrageously bad drugresistance, in which case things would look much worse, and onewould want to guard against that in terms of research investment."
Murray's paper in today's Science roughly coincides with theHarvard unit's publication of two books, with eight more to come,detailing full data on the 107 diseases studied throughout the world.Their titles: The Global Burden of Disease and Global HealthStatistics.
"Recognizing that industries are profit maximizers, as they shouldbe," Murray concluded, "If a pharma or biotech firm came to me andasked: `What does your data mean for us in terms of strategicplanning?' I'd answer that this study is manna from heaven, a wake-up call. For 30 bucks each, or whatever it costs to buy the books,you'd get something that you may have been planning to payhundreds of thousands of dollars to try to figure out." n
-- David N. Leff Science Editor
(c) 1997 American Health Consultants. All rights reserved.