No. 1, January 2005
The Volume and Capacity of Colonoscopy
Procedures Performed at New York City Hospitals in 2002
Jennifer C.F. Leng, MD, MPH, Lorna E. Thorpe, PhD, Gabe E.
Feldman, MD, MPH, MBA, MHA, Pauline A. Thomas, MD, Thomas R.
Frieden, MD, MPH
Suggested citation for this article: Leng JCF, Thorpe LE, Feldman GE, Thomas PA, Frieden TR. The
volume and capacity of colonoscopy procedures performed at New
York City hospitals in 2002. Prev Chronic Dis [serial
online] 2005 Jan [date cited]. Available from: URL:
Colorectal cancer is the second leading cause of cancer death in New York
City. In March 2003, the New York City Department of Health and Mental Hygiene
recommended colonoscopy every 10 years as the preferred screening test for
adults aged 50 years and older in New York City. To screen all eligible adults
in New York City would require that approximately 200,000 colonoscopy exams be
performed annually. As part of this recommendation, we evaluated current
colonoscopy capacity in New York City hospitals.
We surveyed endoscopy suite nursing or administrative staff
at all 66 adult acute care hospitals performing colonoscopy in
New York City. Data on colonoscopy procedures performed in 2002
were collected between February and June 2003.
All hospitals and two affiliated clinics responded. The
number of hospital-based colonoscopy exams performed in 2002 was
estimated to be 126,000. Of these, 53,600 (43%) were estimated to
be for screening. Hospitals reported their maximum annual
capacity to be 195,200, approximately 69,100 more than current
practice. Reported barriers to performing more colonoscopy exams
included inadequate suite time and space (31%),
inadequate staffing (28%), and insufficient patient referrals
In 2003, endoscopy suites at New York City hospitals
performed approximately one quarter of the estimated citywide need of
200,000 screening colonoscopies. Procedures conducted in
outpatient office settings were not assessed. Most endoscopy
suites, particularly private hospitals, reported having the
capacity to conduct additional procedures. Hospitals and
endoscopy suites should prioritize the development of
institutional measures to increase the number of persons
receiving screening colonoscopy.
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Colorectal cancer is the second leading cause of cancer deaths
(after lung) in New York City (NYC) (1) and the leading cause of
cancer death among nonsmokers (2). In 2000, 1600 New Yorkers
died of colorectal cancer (1). In March 2003, based on findings
from an advisory committee on colorectal cancer screening
(Citywide Colon Cancer Control Coalition), the New York City
Department of Health and Mental Hygiene (NYC DOHMH) recommended
colonoscopy every 10 years as the preferred colorectal cancer
screening test for average-risk asymptomatic men and women aged
50 years and older in NYC (2,3). Colonoscopy is highly sensitive,
examines the entire colon, and allows for screening, diagnosis,
and polypectomy in a single visit. While colonoscopy is one of a
series of recommended options in all major national colorectal
cancer screening guidelines (4-7), few institutions have endorsed
it as the preferred screening option. Findings from the
National Polyp Study, however, suggest that periodic colonoscopy could
prevent 76% to 90% of colon cancers (8). The NYC DOHMH recommendation was based on
this estimated effectiveness of colonoscopy in addition to the desire to reduce patient and provider confusion about
multiple screening options.
Nationally, concern over increased colonoscopy demand and insufficient
capacity has raised the question of whether performing colonoscopies on all
eligible adults aged 50 and older is feasible (9). In some U.S. cities,
physicians cite waiting lists of up to eight months, and in extreme situations,
waiting lists have been closed (9). New York City has a high concentration of specialists
and teaching hospitals and therefore may have a greater capacity to perform
colonoscopies compared with other
communities (10). The NYC DOHMH sought to evaluate current colonoscopy
volume and reported maximum capacity in all NYC acute care
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We conducted a telephone survey of nursing or administrative
staff at all NYC adult acute care hospitals from February to June
2003 (11). This included 55 voluntary hospitals, three Veterans
Administration (VA) hospitals, and 11 public hospitals (which
provide care to New Yorkers regardless of their ability to pay). NYC DOHMH staff telephoned hospital endoscopy suites and interviewed
the nurse manager or his or her designee. NYC DOHMH staff requested
to interview the clinic or nurse manager or the person most able
to accurately provide data on the number of colonoscopy exams
performed at that endoscopy suite. If key staff were unavailable
at the time of the call, a follow-up telephone call was
At the close of the interview, NYC DOHMH staff also asked if there
were other clinical sites within the same facility (or affiliated
with the facility) that performed colonoscopy exams. If so, NYC DOHMH
staff interviewed staff at these additional sites. Every distinct
clinical site that performed colonoscopy procedures and was
officially affiliated with the originally targeted facility was
included in the survey. Specific departments, such as
Gastroenterology and General Surgery, were not separately
Using structured survey questions, interviewers asked
respondents to identify the type of clinic in which colonoscopy
exams are performed, the number and specialty of physicians who
perform the procedure, and the waiting time to schedule a
patient. Respondents were asked the total number of exams
performed during the past year (2002), and the approximate
percentage (<25%, 25%–50%, 50%–75%, or >75%) performed for
screening purposes. They were then asked to provide the maximum
number of exams that could be performed per month. Final
questions probed respondents about barriers to performing at full
capacity and willingness to receive more colonoscopy referrals.
No patient-level information was collected.
The citywide need for screening colonoscopy exams was
estimated assuming a steady-state population structure. We
divided the 2000 census count of New Yorkers aged 50 and older
(2,102,578) by the recommended screening colonoscopy interval (10
years) (1). We estimated that to screen all 2 million eligible
New Yorkers every 10 years, NYC would need to perform
approximately 200,000 colonoscopy exams per year.
Survey variables were analyzed using descriptive statistics.
Each hospital reported the total number of exams performed in
2002; the sum of these numbers is the estimated total number of
exams performed in hospitals citywide. The estimated number of
exams performed for screening purposes in 2002 was calculated by
multiplying the midpoint of a given clinic’s reported
screening percentage category by the total number of reported
colonoscopy exams performed in 2002 for that clinic. The same
calculation was performed using the low and high endpoints of a
given screening percentage category to give an estimated range of
the number of exams performed for screening for each clinic. The
estimated maximum number of colonoscopy exams an endoscopy suite
could perform per year was determined by multiplying the reported
maximum number of exams feasible per month by 12.
Potential annual residual capacity was estimated by
subtracting the number of exams performed in 2002 from the
estimated maximum annual number of exams that could be performed.
All estimated values were rounded to the nearest hundred because of
the measurement tool’s lack of precision. The estimated annual
maximum number of exams performed and the estimated annual
potential residual capacity were calculated using the exact
numbers reported and then rounded to the nearest hundred.
Descriptive results were presented according to type of hospital
(voluntary/VA vs public). Data were analyzed using SAS, version
8 (SAS Institute, Inc, Cary, NC).
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We contacted staff at all 69 acute care hospitals in NYC.
Three hospitals did not have endoscopy suites and were excluded
from the survey. Two hospitals had additional affiliated
endoscopy suites; staff from these sites were included in the
survey for a total of 68 sites (Table 1). Most hospitals were
voluntary/VA hospitals (84%); the rest (16%) were public
The majority of staff interviewed (51%) were nurses in
supervisory positions, including nurse managers, charge nurses,
nurse directors, and nurse supervisors. Eighteen percent were
managers or executive administrators, and 10% were physicians or
medical directors. The remaining respondents (21%) were medical
and administrative ancillary staff responsible for maintaining
endoscopy suite colonoscopy schedules. Respondents reported that
a total of 963 physicians were performing colonoscopy exams in
these endoscopy suites at the time of the survey. Ninety-three
percent of physicians were gastroenterologists, and the remaining
7% were colorectal or general surgeons. The median number of
physicians performing colonoscopy exams at public endoscopy
suites was five, compared with 12 at voluntary/VA endoscopy suites.
The median waiting period to schedule a routine screening
colonoscopy was 49 days (range, 21–150 days) at public endoscopy
suites and seven days (range, 0–90 days) at voluntary/VA endoscopy
The total number of reported colonoscopy exams performed in
acute care hospitals in NYC in 2002 was estimated to be 126,000
(Table 2). Endoscopy suites at voluntary/VA hospitals performed
an estimated 117,200 (93%) of the
total estimated colonoscopy exams; public hospitals performed 8800 (7%). The total
number of exams performed for screening was estimated to be
53,600 (range, 37,800–69,000). Sixty-one endoscopy suites (90%) were able to
provide data on both the number of exams performed in 2002 and the estimated
maximum annual number of exams that could be performed; of these, 89% reported a
maximum capacity that was higher than the volume reported for 2002. If maximum
capacity as reported by suites was achieved,
approximately 69,100 additional colonoscopy exams could be
conducted annually (potential residual capacity). Most of the
potential residual capacity (88%) was reported by voluntary/VA endoscopy suites; 12% was reported by public endoscopy suites.
All public hospitals and 50 of 57 voluntary/VA hospitals
reported at least one barrier to performing more colonoscopy
exams. The most commonly reported barriers were inadequate suite
time and space (31%), low physician-staffing levels (28%), low
nurse- and/or technician-staffing levels (28%), and insufficient
patient referrals (24%). Respondents at public facilities more
frequently cited staffing shortages compared with private
facilities (45% [public] vs 25% [private] needed more physicians; 64% [public] vs 21%
more nurses/technicians). At public facilities, respondents also
more often described patient no-shows and cancellations (27% [public] vs
4% [private]) as barriers to performing more exams and less frequently
described a lack of referrals as a barrier (9% [public] vs 26% [private]).
Eighty-eight percent of suites responded yes to the question
“Would you like more referrals?” and 71% responded yes to “Would
you like to be listed for referrals?” Sixty-three percent of
suites reported that they were willing to submit a monthly
colonoscopy report to the health department documenting the
number of exams performed.
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We found that approximately 126,000 colonoscopies are being
conducted annually in NYC hospitals, almost half (43%) of which are performed for screening purposes. Hospitals reported a
potential to conduct an additional 69,100 procedures if barriers
could be sufficiently addressed. In 2002, hospital-based endoscopy suites
performed approximately one quarter of the estimated annual need of 200,000
screening exams. Effective hospital-based improvements could
potentially double this number by enabling endoscopy suites to perform closer to
maximum capacity. The actual total volume of colonoscopy procedures being
conducted in NYC is unknown, because we
currently lack data on the volume of procedures performed in
outpatient office settings.
Public hospital endoscopy suites represented 16% of all suites surveyed, yet
they conducted only 7% of reported procedures, suggesting a lower overall volume
than in the private sector. Nonetheless, public hospitals also reported the
capacity to increase the number of procedures they performed (12% of total
additional capacity). Although this suggests that public facilities, not just
private facilities, may be functioning below full capacity, the long waiting
period to schedule a screening
colonoscopy, the low number of exams performed (relative to
private facilities), the more severe physician staffing
shortages, and the more frequent patient cancellations all imply
that public hospitals face more obstacles when striving to
operate at maximum capacity.
Findings from this survey suggest that, if barriers were
adequately addressed, NYC would have sufficient screening
capacity in hospital endoscopy clinics to meet much of the demand
generated by a focused colonoscopy campaign. Additional capacity
is currently concentrated in private facilities, which primarily
serve patient populations with health insurance. According to a
population-based survey conducted in 2002, only about half of New
Yorkers over the age of 50 reported ever having had a colonoscopy
or sigmoidoscopy, leaving nearly 1 million adults at greater risk
for undetected colon cancer (12). Hospitals and clinics should
develop institutional measures to increase the number of persons
receiving screening colonoscopy. Regular reminders to primary
care physicians to refer patients for colonoscopy, rapid referral
systems to expedite the referral process, protocols to bypass the
initial visit with the endoscopist, and greater efficiency in
colonoscopy procedures could increase the number of colonoscopy
exams performed. Community-based organizations, advocacy groups,
local government, and the medical community could advocate for
legislative changes to increase reimbursement, reduce copays,
and mandate insurance coverage for screening colonoscopy exams.
These same groups should also work to increase public awareness
and further educate providers about colorectal cancer screening.
As a result of this study, the NYC DOHMH developed a colonoscopy
surveillance system to track the volume of colonoscopy procedures
performed in NYC hospitals; this system will allow the NYC DOHMH to
monitor the impact of citywide efforts to increase screening
Particular consideration should be given to increasing the
number of colonoscopy exams performed on uninsured and low-income
patients, who often face significant barriers to health care.
Facilities may be able to improve the efficiency of endoscopy suites and
decrease patient cancellations by the use of patient navigators (staff members
designated to help patients negotiate complex public hospital systems). Shifting
some of the need of the uninsured, low-income population to private hospitals
may also provide a partial solution and could be accomplished through
partnerships among local hospitals.
This study has limitations. We did not attempt to provide data on the
complete universe of colonoscopy procedures in NYC, because
information on the number and location of outpatient office
settings where colonoscopy procedures are performed was
unavailable. However, in NYC, colonoscopy procedures performed in
hospital endoscopy suites do likely represent a significant
proportion of all colonoscopy procedures. One study estimated
that 25% of the estimated 35 million outpatient procedures
performed nationwide in 2001 were performed in physicians’
offices (13). In NYC, this proportion may be similar or even
lower, due to the relatively high proportion of uninsured and
Medicaid patients in NYC (approximately 19% of persons aged 50
and older in 2002) (14) and the high concentration of hospitals in
NYC. Because of low reimbursement, colonoscopy procedures for
Medicaid patients are generally only performed at hospital endoscopy suites by hospital-employed salaried physicians
Another limitation was that our estimated citywide need for 200,000 annual
screening colonoscopy exams was based on the 2000 census count and assumed a
steady-state population structure. This was likely an overestimate, as we did
not account for those who have medical contraindications to colonoscopy, those
who have already been screened, and those who will absolutely refuse the
procedure. This overestimate may be slightly offset by high-risk persons who
require more frequent colonoscopy for surveillance; additionally, as more
eligible persons undergo screening, more colonoscopy procedures will be needed
to perform surveillance on those in whom polyps were identified.
Finally, respondents may have overestimated the annual maximum number of
exams that could be performed. Respondents were not asked specifically to report
whether they were considering
any additional resource investment, such as staff or
equipment, in estimating the maximum number of exams that could
be performed and therefore may have based their estimate on endoscopy suite availability only.
Our study demonstrates a feasible method for obtaining data on
colonoscopy volume and capacity at hospitals in an urban area,
either as a one-time study or as a study repeated at regular
intervals. In June 2003, the NYC DOHMH began collecting similar data on
colonoscopy procedures on a quarterly basis. These data are used
to assess the impact of ongoing agency efforts to increase the
proportion of eligible persons who undergo screening colonoscopy
In 2003, the NYC DOHMH created a coalition of key individuals and
organizations that share an interest in decreasing the incidence
and mortality of colon cancer, the Citywide Colon Cancer Control
Coalition (C5). The mission of the C5 is to improve citywide
colon cancer prevention and control by increasing awareness and
screening. As part of these efforts, the C5/NYC DOHMH developed
guidelines that state: “Most people 50 years of age and older
should undergo colonoscopy every 10 years. Annual fecal occult
blood testing (FOBT) is an acceptable, although not optimal,
alternative for those unwilling or unable to undergo colonoscopy.
Persons at high risk for colorectal cancer should begin screening
with colonoscopy at age 40 or earlier” (2,3). Removing
institutional barriers to increasing screening capacity, as well
as improving access to care, are critical tasks for C5 coalition
members to address; a concerted citywide effort is essential to
achieving these goals.
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The authors are indebted to the members of the Citywide Colon Cancer Control
Coalition (C5) for their assistance in establishing guidelines for colorectal
cancer screening in New York City, and for their efforts in advancing colon
cancer prevention and control. C5 cochairpersons are Harold Freeman, MD (Ralph
Lauren Center for Cancer Care and Prevention), and Sidney J. Winawer, MD
(Memorial Sloan-Kettering Cancer Center). C5 committee chairs include: Barbara
Barrie, Maurice Cerulli, MD (New York Methodist Hospital); Alvaro Genao, MD (North General Hospital); Steven H. Itzkowitz,
MD (Mount Sinai School of Medicine); Alfred I. Neugut, MD, PhD (Columbia University Medical
Center, New York Presbyterian Hospital); Mark B. Pochapin, MD (Jay Monahan
Center for Gastrointestinal Health, New York Presbyterian Hospital, Weill
Medical College of Cornell University); Moshe Shike, MD (Memorial Sloan-Kettering Cancer Prevention and Wellness Program, Memorial Sloan-Kettering
Cancer Center); Robert Schiller, MD (Beth Israel Medical Center, Institute for
Urban Family Health); Thomas Weber, MD (Montefiore Medical Center).
We also thank Drs Kelly Henning and Sidney J. Winawer for their insightful
comments on this manuscript.
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Corresponding author: Jennifer C.F. Leng, MD, MPH, New York City
Department of Health and Mental Hygiene, 125 Worth St, Room 315,
CN6, New York, NY 10013. Telephone: 212-788-4637. E-mail: firstname.lastname@example.org.
Author affiliations: Lorna E. Thorpe, PhD; Gabe E. Feldman,
MD, MPH, MBA, MHA; Pauline A. Thomas, MD; Thomas R. Frieden, MD,
MPH, New York City Department of Health and Mental Hygiene, New
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