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The Landscape of Disease

Patient outcomes and survival rates have altered the patterns of disease over the last 30 years.

Patient Outcomes


Diseases that were once death sentences (heart disease, HIV, cancer) have now become manageable, if not curable, conditions for millions of people. Patients with serious diseases such as cardiovascular disease, HIV, diabetes, and breast cancer are living longer and with better quality of life. Many of these changes are due to unprecedented innovation in the medical device arena. But as we learn more, new questions arise to influence how treatment will be shaped in the future.

The 30th anniversary issue of MD&DI takes a look back at the vastly changing profiles of diseases and the complexities that have emerged based on new understanding of these conditions. This article is not meant to explore all nuances of each disease, but rather to provide a snapshot of the ever-changing landscape of diseases and patients.

Heart Disease

(click to enlarge)
Trends in carotid endarterectomy procedures, 1979-2006. Sources: National Hospital Discharge Survey, National Center for Health Statistics, and National Heart, Lung, and Blood Institute.
By all accounts, the number of patients that die from cardiovascular and heart diseases is in decline. From 1995 to 2005, death rates from cardiovascular disease fell 26.4%, according to a 2009 report from the American Heart Association (AHA). AHA attributes this decline to advances in evidence-based medical therapies (47%) and to changes in risk factors in the population (44%).

(click to enlarge)
Cardiovascular disease mortality trends for males and females in the United States, 1979–2005. Source: National Center for Health Statistics.
Treatment of heart disease is dominated by medical device procedures. In 2006, there were an estimated 1.31 million percutaneous coronary intervention (angioplasty) procedures and 448,000 bypass procedures in the United States. There were also 1.12 million inpatient diagnostic cardiac catheterizations, 114,000 defibrillator implantations, and 418,000 pacemaker procedures.

Patient outcomes research for sudden cardiac death was conducted in 2003 by the Agency for Healthcare Research and Quality (AHRQ). It found that for patients at risk, implantable cardioverter-defibrillators (ICDs), when combined with other therapy, reduced deaths by 24%.

Another study in the AHRQ report used Medicare data, 1987–1995, and California hospital discharge data, 1991–1995, to examine trends in the use of ICDs and outcomes. Researchers found that during those periods, use of ICDs as treatment increased more than tenfold. In that same period, mortality rates fell from 6 to 1.9% for the first 30 days after device implantation and from 19.3 to 11.4% for the year following implantation. The researchers noted, however, that they could not determine whether these outcomes were the result of improved effectiveness of the device or improved patient selection.

(click to enlarge)
Deaths due to cardiovascular disease in the United States from 1900 to 2006 (numbers for 2006 are preliminary). Source: National Center for Health Statistics.
ICDs and antiarrhythmic medications used to prevent sudden cardiac death are effective in reducing deaths, but their impact on quality of life is less clear. AHRQ reported on a study that followed 264 patients with new cases of life-threatening ventricular arrhythmias. For those patients, quality of life decreased at first but gradually improved with time. The overall improvements in quality were greater for patients with ICDs than for patients treated only with pharmaceuticals.

Cardiovascular Disease by the Numbers

26.4
Percentage decrease in death rate from cardiovascular disease, 1995-2005.

98
Percentage of the public that associates automated external defibrillators with restoration of a normal heartbeat.
In addition to surgical measures, emergency response has changed the outcomes of sudden cardiac death, particularly with the increased availability of automated external defibrillators (AEDs). Part of the reason for declining sudden cardiac death rates, says AHA, is increased awareness. The association says the incidence of lay-responder defibrillation, although still low (2% in 2002) is increasing. AHA estimates that as much as 98% of the general public recognizes an AED as something that administers an electrical shock to restore a normal heartbeat among victims of sudden cardiac arrest. These devices are now de rigueur in airports, community centers, event arenas, and even golf courses.

Diabetes

Table I. (click to enlarge) Mortality rates for diabetics per 1000 persons in the United States by sex 1971–2000. Source: Cohort NHANES I, II, and III. Adapted from the Annals of Internal Medicine.
In 1985, diabetes mellitus was the seventh leading cause of death in the United States. From 2003 to 2006, the Health United States 2008 report says that the prevalence of diabetes among adults increased by more than 23% since 1988. Today it is the sixth leading cause of death.

What is troublesome about diabetes is that it weakens the body to other diseases and is often an underlying cause. According to research from CDC, published in 1988, diabetes was selected as an underlying cause on approximately 25% of the death certificates on which it appeared in any field, but it was recorded on only about half of the certificates for persons who had the disease at the time of death. Such disparate recording also makes tracking the disease among patients difficult. In 2007, 5.7 million people were believed to have undiagnosed diabetes, according to CDC.

Fast Facts about Diabetes

An estimated 10% of adults 20 years and older had diabetes in 2003-2006 (diagnosed and undiagnosed).

The prevalence of diabetes among adults has increased by 23% since 1988.

For diabetics, every percentage point drop measured by A1C blood test can reduce the risk of microvascular complications (i.e., eye, kidney, and nerve diseases) by 40%..

Treating diabetes is limited to management of blood glucose, blood pressure, and lipid levels, as well as preventive care for eyes, feet, and kidneys. Type 1 diabetes reduces the normal life span by an average of 5–8 years. However, survival rates are improving mainly due to advances in monitoring and tighter control of blood glucose.

For women, the survival rate has not improved as much as it has for men. In 2007, analysis of the National Health and Nutrition Examination Survey (NHANES) cohort studies found that between 1971 and 2000, the death rate of men with diabetes dropped significantly, in line with the overall decline of the death rate for all Americans. But the death rate for women with diabetes did not decline at all. In fact, the rate for women rose 23%.

Although there is no cure for diabetes, researchers are exploring new technologies that could eradicate the disease. Prevention campaigns play a significant role in reducing the complications and improving life span associated with type 2 diabetes. Type 1 diabetics may find help from tuberculosis vaccines or stem-cell research.

HIV/AIDS

(click to enlarge) Ten countries with the highest estimated number of people living with HIV/AIDS and the number of deaths from AIDS by the end of 2007. Source: UNAIDS/WHO 2008 Report on the Global AIDS Epidemic.
Because it is a relatively new disease, the rate of change from panic to management is perhaps the most visible for HIV and AIDS. HIV was identified in the United States in 1981, but it took less than 10 years for researchers to understand the disease and to develop measures for prevention.

HIV/AIDS by the Numbers

An estimated 22 million adults and children were living with HIV in sub-Saharan Africa at the end of 2007.

Life expectancy at birth in Swaziland is 31 years.

Since the beginning of the epidemic, nearly 600,000 people with AIDS have died in the United States.

In the early 1980s, as many as 150,000 people were infected with HIV each year. By the 1990s the infection rate dropped to about 40,000 each year. In 2006, according to an assessment by UNAIDS and WHO, 37,041 people were diagnosed with the disease in the United States.

CDC estimates that about 1 million people in the United States are living with HIV or AIDS. Of those, only about 25% have been diagnosed.

Diagnosis is key to treatment and containment of HIV. CDC says that timely access to diagnostic HIV test results also improves health outcomes. Its research indicates that nearly half of new HIV infections are identified in healthcare settings. In one CDC report, conducted 2000–2003, 44% of patients interviewed said they were tested for HIV because of illness. Rapid testing before a patient is admitted to a hospital can lead to shorter hospital stays and improved outpatient care, compared with HIV testing after patients are admitted to the hospital.

(click to enlarge) Diagnoses and deaths associated with AIDS, 1981–2007. Source: CDC.
There is no cure for HIV or AIDS, but pharmaceutical cocktails have significantly improved quality of life for those with the disease. Life span has improved with pharmaceutical treatments. CDC's analysis of cohort studies in 2008 found that among patients who received HIV treatment, life expectancy increased by an average of 13 years from 1996 to 2005. Life expectancy predicted at age 20 increased from 36 years to 49 years. And women have been found to have higher life expectancies than men.

That's the good news about HIV. The tragedy of this disease is that those statistics are only applicable for countries in which infected people receive early diagnosis and aggressive treatment.

In Africa, where the disease has run rampant for decades, and where WHO says that 20 million people have died, efforts to treat those affected have been challenging in the best of cases. In some countries, such as Swaziland and Botswana, more than 20% of the population has AIDS. The life expectancy for sub-Saharan countries is 47 years. The results of such overwhelming statistics are an overtaxed infrastructure and decreased access to technology, which makes it even harder to organize treatment.

Although such challenges may seem insurmountable, there are steps being taken among the medical device community to help countries with prevention and management. Low-cost, autodisable injection devices have features that prevent reuse by locking the syringe. These devices will hopefully be used for all injections in Africa. Monitoring and diagnostic devices are being developed that are mobile and function in areas without electricity. Such efforts must be maintained and increased.

Breast Cancer

(click to enlarge) Incidence and mortality rates for breast cancer. Source: Surveillance, Epidemiology, and End Results (SEER) Program and the National Center for Health Statistics.
Although advances have been made in many areas of cancer, breast cancer specifically has had a high profile and therefore increased awareness. Since 2003, breast cancer research has received nearly $600 million from the National Cancer Institute each year. Such awareness and support, as evidenced by all of the topics in this article, are key to finding treatment and increasing survival rates.

Breast cancer is the second most common malignancy found in women. CDC released Report on the Status of Cancer in 2006 that found a 7% decrease in the number of breast cancer cases diagnosed during 2001–2003. This was described as stabilization from the increases seen since the 1980s. The analysis showed that incidence rates for invasive breast cancer decreased each year during 1999–2003.

(click to enlarge) The National Cancer Institute's (NCI's) investment in breast cancer research increased from $548.7 million in fiscal year 2003 to $572.4 million in fiscal year 2007. Source: NCI Office of Budget and Finance.
Even more important is the fact that the overall breast cancer death rate has dropped steadily. The incidence of breast cancer is highest in whites, but African-Americans have higher mortality rates than any other racial or ethnic group in the United States. The gap in mortality between African-Americans and whites is wider now than it was in the early 1990s.

Advances in diagnosis and campaigns to support regular mammography for women have greatly affected mortality rates. The overall five-year relative survival rate for 1999–2005 was 89.1%. Research now centers on finding noninvasive ways to measure abnormalities (i.e., without a biopsy), such as magnetic resonance imaging or positron emission tomography. Analysis in 2006 by AHRQ determined that all of the technologies evaluated could reduce the need for biopsy in women who had an abnormal mammogram, but who did not have cancer. However, as acknowledged in the paper, each noninvasive method would miss some cancers.

Surgical procedures have also progressed, and surgeons often take a more nuanced approach than in previous years. Three basic surgeries are performed, including breast-sparing surgery followed by radiation therapy, mastectomy, and mastectomy with breast reconstruction surgery. Minimally invasive approaches, such as radio-frequency ablation are also being explored, but that method is still in the early stages of development.

Conclusion

The diseases discussed in this article are arguably the most serious in the world, and, because of that, they often get the most attention. These disease sectors receive billions of research dollars from charities, governments, and industry leaders each year. They have powerful advertising campaigns to educate and help the public. And it works. Cardiovascular disease now has more options for treatment than it had 30 years ago, and serious events can be mitigated. Diabetes, although a growing epidemic, has seen extensive breakthroughs to achieve better quality of life for those affected, and research for a cure is promising. HIV and AIDS are manageable diseases provided that prevention, diagnosis, and treatment are handled properly. And breast cancer, if caught early, is a survivable and curable illness. Research and treatment for each disease has seen significant successes, but they will also require more work in the years ahead.

Heather Thompson is managing editor of MD&DI.

Bibliography

“Decline in Breast Cancer Incidence in the United States, 1999–2003,” Centers for Disease Control Morbidity and Mortality Weekly Report. Available from Internet: www.cdc.gov/mmwr/preview/mmwrhtml/mm5622a1.htm#tab.

Gillum, RF, “Sudden Coronary Death in the United States: 1980–1985,” Circulation 79 (1989): 756–765.

Gregg, Edward W et al., “Mortality Trends in Men and Women with Diabetes, 1971–2000,” Annals of Internal Medicine 147, no. 3 (August 2007).

Health United States 2008, Centers for Disease Control. Available from Internet: www.cdc.gov/nchs/hus.htm.

“Life Expectancy of Individuals on Combination Antiretroviral Therapy in High-Income Countries: A Collaborative Analysis of 14 Cohort Studies,” The Lancet 372, no. 9635 (July 2008): 293–299.

“National Diabetes Fact Sheet,” Centers for Disease Control National Center for Health Statistics. Available from Internet: www.cdc.gov/nchs/fastats/diabetes.htm.

Norris, Susan L et al., “The Effectiveness of Disease and Case Management for People with Diabetes—A Systematic Review,” American Journal of Preventive Medicine 22, no. 4s (2002): 15–38.

Report on the Global AIDS Epidemic UNAIDS/WHO 2008. Available from Internet: www.unaids.org/en/KnowledgeCentre/HIVData/GlobalReport/2008/default.asp.

“SEER Cancer Statistics Review 1975–2006,” The National Cancer Institute. Available from Internet: http://seer.cancer.gov/csr/1975_2006/index.html.

“Surgery Choices for Women with Early-Stage Breast Cancer,” Agency for Healthcare Research and Quality (AHRQ). Available from Internet: www.ahrq.gov/consumer/brcanchoice.htm.“Treatment to Prevent Sudden Cardiac Death,” AHRQ. Available from Internet: www.ahrq.gov/clinic/suddcard.htm.

Wasserthiel-Smoller, Nathan et al., “Heart Disease and Stroke Statistics, 2009 Update: A Report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee,” Circulation 119 (2009) e21–e181. Available from Internet: http://circ.ahajournals.org/cgi/content/full/119/2/e21.

Copyright ©2009 Medical Device & Diagnostic Industry
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