IT IS | HOW
DO WE TRACK? | PASSIVE
TRACKING | ACTIVE
TRACKING | DISEASE
SURVEILLANCE | THE
HEALTH OF AMERICA
is Chronic Disease Tracking?
disease tracking, also known as surveillance, is the collection
and analysis of data on chronic conditions. An effective
chronic disease-tracking network should include local, state,
and federal public health agencies that work together to
track the incidence and prevalence of certain chronic diseases.
When combined with a strong biomonitoring program and environmental
hazard tracking (i.e. the Toxic Releases Inventory (TRI)
carried out by the Environmental Protection Agency), health
practitioners and environmental regulators will have the
ability to identify clusters of disease and make informed
decisions when formulating policy that affects health.
do we currently track disease?
are both national and state databases that make up chronic
disease tracking in the United States. In addition, local
public health agencies quite often develop registries as
in the case of children with elevated blood lead levels.
However, most of them are specific to only one disease and
do not communicate with other registries or tracking systems.
tracking systems fall primarily into two categories: active
and passive. One example of a passive tracking system is
a registry. Registries are usually state-based and require
health care providers to report every incidence of a certain
disease encountered when treating patients, including extent,
treatment, and outcome of the illness. Physicians are typically
more familiar with registries than with other types of disease
tracking because of reporting requirements; however, registries
are not the only mechanism used to track diseases. Active
health tracking relies on population-based survey methods,
which include reviewing existing medical records and conducting
interviews with individuals in an attempt to understand
health trends. Active health tracking is the responsibility
of personnel at state and federal public health agencies.
Some local health agencies may elect to conduct their own
surveys and develop their own networks of health care reporting
providers, particularly in the case of communities with
long standing health concerns of toxic or potentially toxic
following are some examples of existing tracking systems:
Surveillance, Epidemiology, and End Results (SEER) program
is an example of a population-based registry of cancer
incidence and mortality in the United States. SEER data
are based on state cancer registry information for a
select group of states and cover only 14% of the population.
Iowa Birth Defects Registry is an example of a state-based
registry. Health care providers are required to report
each birth defect case to the state health department.
In addition, 20 field staff collect birth defect information
from a review of medical records. This registry provides
information for research projects that attempt to identify
risk factors for birth defects.
National Health Interview Survey (NHIS) is designed
to represent the civilian, non-institutionalized population
in the United States. Conducted by the CDC's National
Center for Health Statistics (NCHS), this survey collects
information on illness, accidental injuries, disability,
use of dental, medical and hospital services, and other
health-related topics. It has been conducted continuously
National Hospital Discharge Survey (NHDS) is a continuous
survey based on a sample of medical records for patients
discharged from short-stay hospitals. It collects demographic
information, admission and discharge dates, diagnoses
and procedures performed.
National Ambulatory Medical Care Survey (NAMCS) and
the National Hospital Ambulatory Medical Care Survey
(NHAMCS) are national surveys designed to provide information
on the types and uses of outpatient health care services
for office-based physicians, emergency rooms and hospital
surveys provide a good overview of certain health outcomes
nationally, but were not designed to describe the health
of state and local communities. Nor do the surveys have
the capacity to pinpoint clusters of chronic disease and
link them to communities exposed to environmental contaminants.
national chronic disease monitoring and tracking network
would link these existing data collection capacities together
and incorporate environmental hazard tracking components
into the network. Gaps in knowledge would then be identified
and systems designed to paint a complete picture nationally,
regionally, and eventually statewide and locally.
Chronic Disease Surveillance to Assess Local Problems
remains a challenge! How does one make local observations
of chronic diseases and link them with state and national
registries via a tracking system? Such systems will rely
on the participation of clinicians as well as community
residents who participate in environmental and occupational
exposure surveys. There currently are public health jurisdictions
that are maintaining baseline-data on a variety of symptoms
and conditions that may be related to environmental exposure.
Health of America Depends on it
century has witnessed a shift in the leading causes of morbidity
and mortality from infectious to chronic diseases, but support
for tracking-related efforts has lagged. The EPA and state
environmental agencies have pursued a risk-based regulatory
approach, focusing primarily on extrapolation from animal
toxicology tests, to determine which environmental pollutants
are damaging to humans. At the same time, public health
agencies have used a tracking-based population approach
to try and determine the primary dangers to human health.
there has been little fusion of these two systems, which
has stagnated any attempt to identify environmental hazards
that may have detrimental effects on human health. A vital
step in continuing to address the public health needs of
the United States is the formation of a network that can
both track chronic diseases, clustering of common conditions
and monitoring environmental exposures. This next step in
public health practice will initiate a new paradigm for
both active and passive surveillance of chronic diseases
and disabling conditions that may be clearly linked to environmental