Tracking Diabetes: New York City’s A1C
SHADI CHAMANY, LYNN D. SILVER, MARY T.
BASSETT, CYNTHIA R. DRIVER, DIANA K.
BERGER, CHARLOTTE E. NEUHAUS, NAMRATA
KUMAR, and THOMAS R. FRIEDEN
New York City Department of Health and Mental Hygiene; the Doris Duke
Charitable Foundation; the New York City Health and Hospitals
Corporation; the Centers for Disease Control and Prevention
York City Board of Health mandated the laboratory reporting of hemoglobin
A1C laboratory test results. This mandate established the United States’ first
population-based registry to track the level of blood sugar control in people
with diabetes. But mandatory A1C reporting has provoked debate regarding
the role of public health agencies in the control of noncommunicable diseases
and, more specifically, both privacy and the doctor-patient relationship.
Methods: This article reviews the rationale for adopting the rule requiring
the reporting of A1C test results, experience with its implementation, and
criticisms raised in the context of the history of public health practice.
Findings: For many decades, public health agencies have used identifiable
information collected through mandatory laboratory reporting to monitor the
population’s health and develop programs for the control of communicable
and noncommunicable diseases. The registry program sends quarterly patient
rosters stratified by A1C level to more than one thousand medical providers,
and it also sends letters, on the provider’s letterhead whenever possible, to
patients at risk of diabetes complications (A1C level >9 percent), advising
medical follow-up. The activities of the registry program are similar to those of
programs for other reportable conditions and constitute a joint effort between a
governmental public health agency and medical providers to improve patients’
Address correspondence to: Shadi Chamany, Director, Diabetes Prevention and
The Milbank Quarterly, Vol. 87, No. 3, 2009 (pp. 547–570)
c ? 2009 Milbank Memorial Fund. Published by Wiley Periodicals Inc.
S. Chamany et al.
Conclusions: Mandatory reporting has proven successful in helping combat
other major epidemics. New York City’s A1C Registry activities combine both
traditional and novel public health approaches to reduce the burden of an
epidemic chronic disease, diabetes. Despite criticism that mandatory report-
ing compromises individuals’ right to privacy without clear benefit, the early
feedback has been positive and suggests that the benefits will outweigh the
potential harms. Further evaluation will provide additional information that
other local health jurisdictions may use in designing their strategies to address
Keywords: Diabetes, disease registry, surveillance, privacy.
adults with diabetes experience more than 20,000 diabetes-related hos-
cases of end-stage renal disease, with hospitalizations alone accounting
for $481 million in medical costs (Kim, Berger, and Matte 2006). Dia-
betes is the fifth leading cause of death, and diabetes mortality rates are
two to three times higher in blacks and Hispanics than in whites and
two times higher in those living in low-income neighborhoods than in
high-income neighborhoods (Kim, Berger, and Matte 2006; New York
City Department of Health and Mental Hygiene 2008).
Controlling blood sugar (as measured by A1C levels), blood pres-
sure, and LDL cholesterol can substantially reduce the risk of long-term
complications of diabetes and decrease mortality (Adler et al. 2000;
Davidson, Ansari, and Karlan 2007; Diabetes Control and Complica-
UK Prospective Diabetes Study Group 1998). In New York City, as in
the rest of the United States, control of these risk factors for complica-
tions is suboptimal. In a 2004 survey, less than 10 percent of New York
City adults with diabetes had adequate control of three key predictors
of mortality: blood sugar, blood pressure, and cholesterol. Furthermore,
22 percent—more than the city average—were smokers (Thorpe et al.
n surveys conducted between 1994 and 2004, the
proportion of New York City adults reporting having diabetes more
than doubled, from 3.7 to 9.2 percent (New York City Department
Tracking Diabetes: New York City’s A1C Registry
Faced with the increasing burden of diabetes and its complications
in New York City’s population, the New York City Department of
Health and Mental Hygiene reviewed both its existing disease control
programs (e.g., tuberculosis, HIV infection, lead poisoning, hepatitis C
infection) and its ongoing work in improving the quality of diabetes
care to craft a strategy to address diabetes control. Features that the
disease control programs have in common are mandatory reporting of
test results, provision of test results to patients and/or providers, general
education efforts, provision of treatment or resources to access care, and
In 2005, the department submitted a proposal to the New York City
Board of Health that would require most laboratories to report to the
Department of Health and Mental Hygiene 2005). Following a period
of public comment, in late 2005 the board of health approved this
proposal. In proposing a mandatory reporting system for A1C results,
the department built on the experience of these existing disease control
programs by establishing a disease surveillance system that would both
track the condition in the population and directly support individuals
in New York City. It was also the first U.S. mandate requiring A1C
results to be reported to a public health authority.
controversy. Although the period of public comment attracted fairly
modest attention, experts across various disciplines later published pa-
pers both supporting and opposing the measure (Banerji and Stewart
2006; Barnes, Brancati, and Gary 2007; Fairchild 2006; Fairchild and
Alkon 2007; Fairchild, Bayer, and Colgrove 2007; Goldman et al.
2008b, 2008a; Krent et al. 2008; Mariner 2007; Monitoring Diabetes
Treatment in New York City 2006; Steinbrook 2006). The appropriate
role of public health and the use of traditional public health tools in
the control of chronic disease were the principal issues raised in many of
these papers, and this debate has become increasingly critical given the
growing burden of chronic disease in the population (Frieden 2004).
the program, presents the public health rationale for creating the A1C
Registry, describes how registry data are collected and used, and consid-
ers the issues raised by critics, particularly the role of public health in
S. Chamany et al.
Public Health Rationale for the A1C
Disease registries can improve outcomes in people with chronic
conditions (Bodenheimer, Wagner, and Grumbach 2002a, 2002b;
Gudbj¨ ornsdottir et al. 2003; Kupersmith et al. 2007; Larsen, Cannon,
and Towner 2003; Tsai et al. 2005). Registries provide a mechanism by
which providers can identify individuals in greatest need of follow-up or
referral and also monitor disease indicators in their patient population
in place. The department’s position was that a population-based A1C
registry could fill a critical gap in the health care system’s infrastruc-
ture until such innovations as electronic medical records with a registry
function were more widely adopted, enabling providers to monitor and
improve diabetes care.
Features and Uses of the A1C Registry
Theregistry’s informationis usedto monitor glycemiccontrol overtime
support medical providers and their patients (see table 1). Laboratories
that conduct A1C testing for New York City residents (regardless of
the laboratory’s location) and are already reporting electronically other
laboratory test results to the department are subject to the mandate.
Laboratories report test results to the department using a secure file
transmission method. Although laboratories that provide incomplete
data or fail to report may be fined or have their permits revoked under
the city’s health code, no such actions have yet been taken.
The department analyzes registry data to assess variations in testing
patterns, health care utilization, and glycemic control by age, sex, ge-
ographic location (i.e., zip code or borough), and type of health care
facility (e.g., hospital, federally qualified health center, solo practice).
The general laboratory reporting rule governing the A1C mandate does
not require reporting race and ethnicity, so data on these variables are
incomplete. Longitudinal analyses will examine changes in patients’
level of glycemic control over several years for cohorts defined by year of
entry into the registry.
Tracking Diabetes: New York City’s A1C Registry
Features of the A1C Registry
Who reports? Laboratories (within or outside New York City)
with a New York State license and serving New
York City residents that already report
electronically via file upload to the department
for other reportable conditions
Test records for individuals who have had an A1C
test done at a mandated laboratory, within 24
hours of the result
• A1C test result
• Date of test
• Name of testing facility
• Name of ordering facility/provider and address
• Name of person tested, his/her address and date of
The treating medical provider(s) (defined as the
individual provider and/or institution that
ordered the last test) or the person who was the
subject of the test
• Individual providers receive a quarterly patient
roster, ordered by A1C level, by mail.
• Facilities receive similar rosters for all providers
linked to that facility.
• Patients who opt out are not included in rosters.
• Letters are sent to patients 18 years and older who
have A1C >9 percent or who are overdue for
• Patients who opt out do not receive a letter.
• Patients can opt out of the interventions,
including receiving letters or being on provider
rosters, by contacting the department by phone,
post, or online.
• Patients cannot opt out of the registry, as
laboratory reporting is mandatory.
What is reported?
What information is
Who can receive
How do providers
How do patients
Can patients opt out?
Supporting Patient Care
The goals of the department’s provider and patient tools are (1) to
raise providers’ awareness regarding the level of glycemic control in
their patient panels; (2) to enable providers to take action for those
at highest risk; and (3) to inform and guide patients who are at risk