No. 1, January 2005
New Mexico’s Capacity for Increasing the Prevalence of
Colorectal Cancer Screening With Screening Colonoscopies
Richard M. Hoffman, MD, MPH, S. Noell Stone, MPH, Carla
Herman, MD, MPH, Ann Moore Jung, MEd, Jane Cotner, MS, David
Espey, MD, Richard Kozoll, MD, Michael W. Gavin, MD
Suggested citation for this article: Hoffman RM, Stone
SN, Herman C, Jung AM, Cotner J, Espey D, et al. New
Mexico’s capacity for increasing the prevalence of
colorectal cancer screening with screening colonoscopies.
Prev Chronic Dis [serial online] 2005 Jan [date
cited]. Available from: URL:
Colorectal cancer screening rates are low throughout the
United States. Colonoscopy has been recommended as a
cost-effective strategy for colorectal cancer screening and
prevention. We evaluated New Mexico’s capacity to increase
the prevalence of colorectal cancer screening using
We identified New Mexican gastroenterologists from state
licensing data and from endoscopic manufacturers. We surveyed
their weekly number of colonoscopies, capacity for additional
screening colonoscopies, and barriers to increasing capacity. We
used census data, published data on the yield of screening
colonoscopy, and professional society guidelines for cancer/polyp
surveillance to estimate the additional colonoscopies required to
increase the state’s prevalence of endoscopic
Forty gastroenterologists, representing all 11 group practices
in the state, and nine of 12 solo practitioners responded. They
estimated that their weekly procedure capacity could be increased
by 41%, from 832 to 1174 colonoscopies. We estimated an annual
capacity increase of 14,880 procedures, which could increase the
prevalence of endoscopic colorectal cancer screening from the
current 35% to about 50% over five years. Lack of support staff,
space, and physicians were barriers to increasing screening.
Implementing a screening colonoscopy strategy could achieve
the goal of a higher level of colorectal screening. However,
achieving more universal screening would require additional
Back to top
Colorectal cancer is the third most frequently diagnosed
cancer in New Mexico and the second leading cause of cancer death
(1). Randomized controlled trials of fecal occult blood testing
(FOBT) have shown that screening reduces the incidence and
mortality of colorectal cancer (2-4). Flexible sigmoidoscopy has
also been shown to reduce colorectal cancer mortality in
well-designed case-control studies (5,6). Professional
organizations have identified colorectal cancer screening as an
effective, high-priority intervention (7-10). Acceptable
modalities include FOBT, flexible sigmoidoscopy, colonoscopy, and
double-contrast barium enema.
Despite those supportive practice
guidelines, colorectal cancer screening rates remain low.
National data show that just over 50% of adults aged 50 years and
older are considered to be appropriately screened for colorectal
cancer with either a FOBT within one year or an endoscopic
procedure within 10 years (11,12). In New Mexico, 2001 survey
data from the Centers for Disease Control and Prevention’s
(CDC’s) Behavioral Risk Factor Surveillance System (BRFSS)
reported that only 23.2% of adults aged 50 years and older had
undergone FOBT testing in the previous two years and that 34.5% had
undergone a flexible sigmoidoscopy or colonoscopy in the previous
five years (13). The BRFSS survey did not obtain information
about radiographic screening tests. Overall, only 48% of the
adult population was considered currently screened (analysis by
the New Mexico BRFSS Unit, July 2003); this likely is an overestimate given the limited concordance of the BRFSS
colorectal cancer screening questions with medical records (14) and
the potential selection bias introduced by the telephone survey
Efforts to improve screening rates have included celebrity
endorsements by Katie Couric (15), the CDC’s Screen for
Life campaign (16), the American Cancer Society’s “Polyp Man”
public service announcements (17), and President Clinton’s
2000 declaration that March would henceforth be National
Colorectal Cancer Awareness Month (18). Medicare began
reimbursing for colorectal cancer screening with FOBT and
flexible sigmoidoscopy in 1998 and has reimbursed screening
colonoscopy at 10-year intervals for average-risk adults since
July 2001 (19). The National Center for Quality Assurance has
established a new Health Plan Employer Data and Information Set
measure of colorectal cancer screening performance standards for
health care plans beginning in 2004 (20,21).
Although there is no direct evidence for its screening
efficacy, colonoscopy is the most accurate diagnostic test and
offers the potential to remove premalignant growths. Winawer and
colleagues estimated that colonoscopy could reduce the incidence
of colorectal cancer by a range of 76% to 90% (22). Economic analyses have
also found that colonoscopy is a cost-effective screening
strategy for colorectal cancer (23-25). The American College of
Gastroenterology practice guidelines recommend colonoscopy to be
the first screening option (26). However, experts have questioned
the feasibility of increasing screening through colonoscopy
because the number of colonoscopists and infrastructure needed to
screen the population may be inadequate (9). We conducted a
survey of New Mexican gastroenterologists to determine the
feasibility of implementing a colonoscopic screening strategy to
improve statewide screening rates.
Back to top
The Colorectal Cancer Screening Working Group of the Clinical
Prevention Initiative (CPI) evaluated screening capacity by
conducting a mailed survey of endoscopists in New Mexico. The CPI
membership, composed of public health and health care
professionals, is supported by the New Mexico Department of
Health and the New Mexico Medical Society to promote more
effective delivery of practice-based preventive services
throughout the state of New Mexico.
We identified endoscopists in New Mexico by using data from
the Board of Medical Examiners, contacting manufacturers of
endoscopic equipment, and obtaining the membership lists of a
statewide gastroenterology journal club, the New Mexico Medical
Society, and the American Medical Association. Eligible subjects
for this analysis were gastroenterologists actively practicing in
New Mexico, which included 40 gastroenterologists practicing in
one of the 11 group practices and 12 solo practitioners.
The CPI colorectal cancer group developed a brief survey to
obtain information about endoscopic capacity, including
colonoscopies and flexible sigmoidoscopies (Table 1). Questions
were based on literature review, the BRFSS, and the clinical
experience of the CPI colorectal cancer group, which included two
gastroenterologists and two internists who performed
sigmoidoscopy. Revisions were based on pilot testing the survey
with clinical colleagues and other members of the CPI. The survey
was conducted between October and December 2001. Subjects were
mailed a letter introducing the survey and asking for their
participation. The survey was printed on a postcard with a
return address and postage. For nonrespondents, we followed up
with telephone calls and repeat mailings two weeks after the
We used simple, descriptive nonparametric statistics to
estimate the weekly median number of procedures performed by endoscopists in group practice and solo practice and the
estimated weekly potential increase in capacity.
Endoscopic capacity. We determined the number of
additional screening colonoscopies that could be performed using
survey responses. We averaged responses when multiple members of
a group practice completed the survey and provided different
estimates for the weekly number of baseline and additional
procedures performed by the practice. We imputed the weekly
number of baseline and additional colonoscopies for the
solo-practitioner nonrespondents using data from the responding
solo practitioners. For the annual number of colonoscopies, we
assumed that endoscopists performed procedures for 40 weeks. We
performed similar estimates for the number of flexible
Volume of colonoscopies. We modeled the number of
procedures required for a statewide screening colonoscopy
strategy. To identify the number of subjects potentially eligible
for colonoscopic screening, we used data from the 2000 United
States Census for New Mexico that reported 468,000 resident
adults aged 50 to 85 (27). Based on the census data, we evaluated
the additional number of screening colonoscopies required to
increase the prevalence of current screening by 5% (23,400
additional people being screened), 10% (46,800), 15% (70,200),
20% (93,600), and 25% (117,000) during a five-year period. We
assumed that the additional screening procedures would be
performed in equal numbers during the five-year period. We then
modeled the number of surveillance procedures that would be
required following the initial screening colonoscopy. We used
clinical data on the yield of colorectal cancers and adenomatous
polyps from a recent large Department of Veterans Affairs (VA)
colonoscopic screening trial (28) and consensus guidelines for
the timing of surveillance procedures (10).
- Colorectal cancer detection level: 1%
- Adenomatous polyp detection level: 37%
- Advanced (villous, dysplastic, >1 cm, >2 polyps)
polyp level: 15%
- Surveillance following colorectal cancer detection: 6 months
and 3 years
- Surveillance following 1–2 adenomatous polyps <10 mm:
- Surveillance following advanced polyp: 3 years
We assumed that half of the cancers diagnosed in the fifth year
would have a six-month surveillance colonoscopy that same year.
The colonoscopic screening trial had a higher proportion of
subjects with positive family history of colorectal cancer than
the general population and may have overestimated the yield of
screening. Results from an employee-health colonoscopic screening
program did show a lower yield than the VA study (29). Therefore, we
performed a sensitivity analysis by reducing the expected rates
of detected colorectal cancers and adenomatous polyps by
We entered survey data into a Microsoft Access (Microsoft Corporation,
Seattle, Wash) database. We
performed statistical analyses with SAS (SAS Institute, Inc, Cary, NC) (30).
Back to top
We received procedure information from nine of 12 solo practitioners and all 11 group practices,
representing 40 endoscopists (two to eight practitioners per
group). Physicians and
practices were based in 12 different counties. Ten of 11 group
practices and six of 12 solo practitioners were located in urban
areas, defined by the Census Bureau as having population
densities >1000 per square mile (31).
Table 2 shows the
numbers of procedures currently being performed weekly and the
weekly capacity for additional procedures, which were stratified by type of
practice. Overall, gastroenterologists reported performing 832
colonoscopies a week; they estimated being able to increase their
capacity by an additional 342 (41%) procedures each week.
Assuming a 40-week work year, each endoscopist in group
practice could perform an estimated 252 additional colonoscopies
every year and solo practitioners could perform an estimated
400 additional colonoscopies. Statewide, endoscopists could
perform an estimated 13,680 additional colonoscopic procedures
each year. If the nonresponding solo practitioners performed similarly to those
completing the survey, the estimated
annual additional capacity for colonoscopy would be 14,880
We show the estimated number of additional colonoscopies
required to increase screening prevalence by 5%, 10%, 15%, 20%,
and 25% during a five-year period in
Table 3. The total number of
procedures includes screening procedures based on the 2000 New
Mexico census and surveillance procedures based on the yield of
cancer and adenomatous polyps detected with screening. The second
column of numbers reflects the yield of advanced neoplasia based
on the VA study data from Lieberman and colleagues. The third
column is a sensitivity analysis showing the estimated number of
colonoscopies if the cancer yield was 0.5% and the overall yield
of adenomatous polyps was 20%. If all patients with adenomatous
polyps underwent colonoscopic surveillance at three years (rather
than just patients with advanced neoplasia), the annual number of
procedures would be increased by about 5%. Overall, a screening
colonoscopy strategy could increase the prevalence of current
colorectal cancer screening by about 15%.
Although our analyses focused on colonoscopies, we also
obtained information on flexible sigmoidoscopy. All but one of
the group practices performed flexible sigmoidoscopies, but only
five of the solo practitioners performed them. Overall, however,
only 165 procedures were performed weekly; respondents estimated
that they could perform an additional 188 procedures.
The barriers to performing additional endoscopic tests are
shown in Table 4. Only one group practice reported no barriers
to performing additional procedures, and four solo
practitioners reported no barriers. Lack of support staff, space
(for procedures and/or recovery room), and physicians were the
most frequently cited problems for the group and solo
Back to top
New Mexico gastroenterologists responding to our survey
estimated having the capacity to increase their weekly number of
colonoscopies by about 41%, from 832 to 1174. This substantial
increase could raise the prevalence of current endoscopic
screening by approximately 15% within five years. The most recent
BRFSS data report that 35% of New Mexican adults are currently
screened by endoscopy; thus, the increased endoscopic capacity
would be just sufficient to achieve 50% colorectal cancer
screening. However, this level of screening would still be far
short of the 70% to 90% screening reported for mammography,
Papanicolaou (Pap) smears, and prostate-specific antigen (PSA)
tests (32,33). Additional recommended screening modalities,
including FOBT, flexible sigmoidoscopy, and radiological studies
would be needed to achieve a higher level of screening (7,8).
Rex and Lieberman modeled a strategy for implementing
colonoscopy as the preferred screening procedure in the United
States (9). Based on a 10-year screening interval and assuming
that 10% of the adult population aged 50 to 70 would be screened
every year, they estimated an annual need for 7.7 million
colonoscopies. After reducing this number for patients with
significant comorbidities, noncompliance, and current screening,
they estimated that approximately 2.56 million additional
colonoscopies would need to be performed. Based on a government
report that 4.4 million colonoscopies were performed in 1999, Rex
and Lieberman concluded that implementing screening colonoscopy
would require a 58% increase in capacity. This figure may be an
underestimation because they modeled screening only until age 70.
Given that the incidence of colorectal cancer increases steadily
with age (34) and that screening could appropriately be offered
until age 80 (35), the actual number of additional colonoscopies
could be quite higher.
Even if Rex and Lieberman correctly estimated the number of
additional procedures to fully implement screening colonoscopy,
the demand in New Mexico would likely exceed the capacity of the
state’s endoscopists — despite their already high
level of productivity. Endoscopists in New Mexico reported
performing about 16 to 20 colonoscopies weekly, which compares
quite favorably with data obtained from the National Cancer
Institute’s (NCI’s) nationwide Survey of Colorectal
Cancer Screening Practices. The 346 gastroenterologists
responding to the survey, conducted between November 1999 and
April 2000, performed an average of only 31.7 colonoscopies
monthly, including 12.4 for screening (36).
Rex and Lieberman acknowledged that increasing the level of
colonoscopies would be challenging (9). One of their solutions
was for gastroenterologists to perform 50% fewer flexible
sigmoidoscopies to make time to perform colonoscopies (9). They
cited Medicare data showing that 543,502 flexible sigmoidoscopies
were performed in 2000. The nationwide NCI survey estimated that
gastroenterologists performed 25% of sigmoidoscopies, which
suggests that nearly 70,000 fewer procedures could be performed
in just the Medicare population alone (36). However, this survey
indicated that sigmoidoscopies comprised about 30% of the
colorectal endoscopic procedures performed by
gastroenterologists. Our data showed that sigmoidoscopy comprised
only 16% of the lower endoscopic procedures performed by
gastroenterologists in New Mexico, implying practice patterns had
already changed substantially. Further reductions in performing
sigmoidoscopy may not be feasible, especially because many of the
sigmoidoscopic procedures are diagnostic.
Another strategy for implementing screening colonoscopy would
be to increase the number of procedures performed by other
medical providers. The NCI survey reported that general surgeons
performed 30% of colonoscopies (36). However, on average, the 251
general surgeons performed fewer than eight colonoscopies
monthly, including about three screening colonoscopies. While
nearly half of the gastroenterologists performed at least 10
screening colonoscopies monthly, only 6% of general surgeons
reached this level. The NCI survey also obtained data on
colorectal cancer screening practices by primary care physicians
(37). Among the 1235 respondents, fewer than 5% of primary care
providers reported performing colonoscopy, and most of them
performed fewer than five procedures monthly. Although 29% of
primary care respondents performed sigmoidoscopy, fewer than 20%
performed more than 10 procedures monthly.
Increasing screening colonoscopy by having general surgeons
and primary care physicians perform these procedures does not
seem to be a feasible strategy for New Mexico. When we conducted
our survey, endoscopic equipment manufacturers provided us
information on all practices that had purchased equipment for
performing colorectal procedures. In addition to
gastroenterologists, we also identified surgeons and primary care
physicians as owners of endoscopic equipment. Three of the eight
colorectal cancer surgeons in the state identified as performing
colonoscopies responded to the survey; they were performing 18
colonoscopies weekly and estimated that they could increase their
capacity by 12 weekly. None of the 28 primary care providers who
performed endoscopy reported performing colonoscopy. Only six
primary care endoscopists reported performing five or more
(maximum eight) flexible sigmoidoscopies weekly; the majority
performed less than two. Another problem with relying on
nongastroenterologists to perform endoscopy is that their low
procedure volume may be associated with diminished proficiency
Rex and Lieberman further noted that increasing capacity for
screening colonoscopy would require more efficiency in endoscopy
suites (9). Our respondents consistently reported that limited
space and support staff were barriers to performing more
procedures. Our respondents also reported that having more
physicians would help improve capacity. Strategies to increase
the number of gastroenterologists would likely target a
training program; New Mexico does have a university
gastroenterology fellowship program. However, Rex and Lieberman
questioned the wisdom of training more endoscopists because
accurate, cost-effective, noninvasive tests — such as
virtual colonoscopy or fecal DNA assays — are likely to be
used increasingly, thus reducing the need for screening
colonoscopies (9). Another barrier facing New Mexico is a
relatively impoverished population with a high proportion of
uninsured adults (39); financial incentives may also be necessary
to attract and retain specialists. Although there is little data
supporting the practice, nonphysicians could also be trained to
perform colonoscopy (40).
Our study had some important limitations. We were generally unable to
validate the self-reported weekly number of procedures performed by each
practice or solo practitioner. However, one group of three gastroenterologists,
who estimated that they annually performed 3000 procedures, also reviewed their
billing records for the previous year. These data showed that they had
overestimated their current capacity by 10% — they actually performed only 2760
procedures. The estimated increased capacity also depends upon the respondents
being able to accurately assess the practice’s ability to perform additional
tests, which could not be validated. However, if other practices similarly
overestimated their current capacity, then the estimates for the absolute number
of additional procedures could also be inflated.
Another potential limitation was that we used a simplified model. On the demand side, we assumed that
patients would be compliant with surveillance-testing
recommendations and that the population would be stable. On the
supply side, we assumed that the number of gastroenterologists in
the state would be stable. We also assumed that the supply of endoscopists would be matched with patients needing procedures.
However, New Mexico has problems retaining specialists (41), and
even having a sufficient number of gastroenterologists may not
ensure comprehensive screening coverage. In New Mexico, access to
care may be severely limited by geographic distance. New Mexico
is a large, mostly rural state; almost all of the
gastroenterologists practice in urban areas. Nonetheless, our
intention was not to precisely estimate screening capacity but
rather to provide a general assessment of the feasibility of
implementing screening colonoscopy, including identifying
We conclude that New Mexico has the colonoscopic capacity to
substantially increase the prevalence of adults with current
colorectal cancer screening. The state could probably achieve a
level of 50% current endoscopic screening by colonoscopy alone.
However, New Mexico lacks the capacity to implement a fully
comprehensive screening colonoscopy strategy. Efforts to achieve
more universal screening would also require additional modalities
such as FOBT, flexible sigmoidoscopy, and barium enema in addition to
health care policies requiring screening coverage. More efficient
use of colonoscopy would also be necessary, including withholding colonoscopic screening from patients with limited life expectancy
(7), performing surveillance colonoscopy at appropriate intervals
(42), and considering a single lifetime-screening colonoscopy
Back to top
The project was supported by the New Mexico Department of
Health, contract 02/665.4200.0189. We appreciate the comments
of Amnon Sonnenberg, MD, MSc and Meg Adams-Cameron, MPH, who reviewed
an early draft of the manuscript. We also
appreciate the support of the New Mexican endoscopists who
responded to our survey. The material in this article was presented in
part at the American Society of Gastrointestinal Endoscopy
Meeting, Orlando, Fla, May 19, 2003.
Back to top
Corresponding author: Richard M. Hoffman,
MD, MPH, New Mexico VA Health Care System 111GIM, 1501 San
Pedro SE, Albuquerque, NM 87108. Telephone: 505-256-2727. E-mail: firstname.lastname@example.org. The author is also
affiliated with the University of New Mexico Cancer Center.
Author affiliations: S. Noell Stone, MPH, University of New
Mexico Cancer Center, Albuquerque, NM; Carla Herman, MD, MPH, University of New
Mexico Cancer Center, Albuquerque, NM; Ann Moore Jung, MEd, New Mexico Medical
Society, Albuquerque, NM; Jane Cotner, MS, University of New Mexico Cancer Center,
David Espey, MD, Indian Health Services, Centers for Disease
Control and Prevention, Albuquerque, NM; Richard Kozoll, MD, New Mexico Medical
Society, Cuba, NM; Michael W. Gavin, MD, Lovelace Sandia Health System,
Back to top
- Jemal A, Tiwari RC, Murray T, Ghafoor A,
Samuels A, Ward E, et al.
Cancer statistics, 2004. CA Cancer J Clin 2004;54:8-29.
- Hardcastle JD, Chamberlain JO, Robinson MH, Moss SM, Amar
SS, Balfour TW, et al.
Randomised controlled trial of
faecal-occult-blood screening for colorectal cancer. Lancet
- Mandel JS, Church TR, Bond JH, Ederer F, Geisser MS, Mongin
SJ, et al.
The effect of fecal occult-blood screening on the
incidence of colorectal cancer. N Engl J Med
- Kronborg O, Fenger C, Olsen J, Jorgensen OD, Sondergaard O.
Randomised study of screening for colorectal cancer with
faecal-occult-blood test. Lancet 1996;348(9040):1467-71.
- Muller AD, Sonnenberg A.
Prevention of colorectal cancer by
flexible endoscopy and polypectomy. A case-control study of
32,702 veterans. Ann Intern Med 1995;123(12):904-10.
- Selby JV, Friedman GD, Quesenberry CP Jr, Weiss NS.
case-control study of screening sigmoidoscopy and mortality from
colorectal cancer. N Engl J Med 1992;326(10):653-7.
- Pignone M, Rich M, Teutsch SM, Berg AO, Lohr KN.
for colorectal cancer in adults at average risk: a summary of the
evidence for the U.S. Preventive Services Task Force. Ann Intern
- Smith RA, Cokkinides V, Eyre HJ; American Cancer Society.
American Cancer Society
guidelines for the early detection of cancer, 2003. CA Cancer J Clin 2003;53(1):27-43.
- Rex DK, Lieberman DA.
Feasibility of colonoscopy screening:
discussion of issues and recommendations regarding
implementation. Gastrointest Endosc 2001;54(5):662-7.
- Winawer S, Fletcher R, Rex D, Bond J, Burt R, Ferrucci J,
et al. Colorectal cancer screening and surveillance: clinical
guidelines and rationale-Update based on new evidence.
- Seeff LC, Nadel MR, Klabunde CN, Thompson T, Shapiro JA,
Vernon SW, et al.
Patterns and predictors of colorectal cancer
test use in the adult U.S. population. Cancer
- Centers for Disease Control and Prevention.
cancer test use among persons aged ≥ 50 years--United States,
2001. MMWR 2003;52:193-6.
- Centers for Disease Control and Prevention.
Risk Factor Surveillance System data — 2002. Atlanta (GA): Centers for
Disease Control and Prevention; 2002.
- Nelson DE, Holtzman D, Bolen J, Stanwyck CA, Mack KA.
Reliability and validity of measures from the Behavioral Risk
Factor Surveillance System (BRFSS). Soz Praventivmed 2001;46
- Cram P, Fendrick AM, Inadomi J, Cowen ME, Carpenter D,
The impact of a celebrity promotional campaign on the
use of colon cancer screening: the Katie Couric effect. Arch
Intern Med 2003;163(13):1601-5.
- Centers for Disease Control and Prevention.
life. Atlanta (GA): Centers for Disease Control and Prevention; 2004.
- Reynolds T.
Colossal colon, polyp man aimed at increasing
screening. J Natl Cancer Inst 2003;95(8):575.
- Clinton WJ.
National colorectal cancer awareness month, 2000. Washington (DC): Office of the Press Secretary;
- Walsh JM, Terdiman JP.
Colorectal cancer screening:
scientific review. JAMA 2003;289(10):1288-96.
- National Committee for Quality Assurance. HEDISª 2004 Summary Tables of Measures and Product
Lines. Washington (DC): NCQA; 2004.
- Schneider EC, Riehl V, Courte-Wienecke S, Eddy DM, Sennett
C. Enhancing performance measurement: NCQA's road map for a
health information framework. National Committee for Quality
Assurance. JAMA 1999;282(12):1184-90.
- Winawer SJ, Zauber AG, Ho MN, O'Brien MJ, Gottlieb LS, Sternberg SS,
Prevention of colorectal cancer by colonoscopic polypectomy. The National
Polyp Study Workgroup. N Engl J Med 1993;329(27):1977-81.
- Pignone M, Saha S, Hoerger T, Mandelblatt J.
Cost-effectiveness analyses of colorectal cancer screening: a
systematic review for the U.S. Preventive Services Task Force.
Ann Intern Med 2002;137(2):96-104.
- Lieberman DA.
Cost-effectiveness model for colon cancer
screening. Gastroenterology 1995;109:1781-90.
- Sonnenberg A, Delco F, Inadomi JM.
colonoscopy in screening for colorectal cancer. Ann Intern Med
- Rex DK, Johnson DA, Lieberman DA, Burt RW, Sonnenberg A.
Colorectal cancer prevention 2000: screening recommendations of
the American College of Gastroenterology. American College of
Gastroenterology. Am J Gastroenterol 2000;95(4):868-77.
- U.S. Census Bureau. American FactFinder; Profile of
general demographic characteristics. Washington (DC): U.S. Census Bureau; 2000.
- Lieberman DA, Weiss DG, Bond JH, Ahnen DJ, Garewal H,
Use of colonoscopy to screen asymptomatic adults for
colorectal cancer. Veterans Affairs Cooperative Study Group 380.
N Engl J Med 2000;343(3):162-8.
- Imperiale TF, Wagner DR, Lin CY, Larkin GN, Rogge JD,
Risk of advanced proximal neoplasms in asymptomatic
adults according to the distal colorectal findings. N Engl J Med
- SAS Institute, Inc. SAS/STAT® User's Guide, Version 8. Cary (NC): SAS Institute, Inc; 1999-2001.
- U.S. Census Bureau. Census 2000 urban and rural
classification. Washington (DC): U.S. Census Bureau; 2003.
- Nelson DE, Bland S, Powell-Griner E, Klein R, Wells HE,
Hogelin G, et al.
State trends in health risk factors and receipt
of clinical preventive services among US adults during the 1990s. JAMA 2002;287(20):2659-67.
- Sirovich BE, Schwartz LM, Woloshin S.
Screening men for
prostate and colorectal cancer in the United States: does
practice reflect the evidence? JAMA 2003;289(11):1414-20.
- Weir HK, Thun MJ, Hankey BF, Ries LA, Howe HL, Wingo PA,
et al. Annual report to the nation on the status of cancer,
1975-2000, featuring the uses of surveillance data for cancer
prevention and control. J Natl Cancer Inst
- U.S. Preventive Services Task Force.
Screening for colorectal cancer: recommendation and
rationale. Ann Intern Med 2002;137(2):129-31.
- Brown ML, Klabunde CN, Mysliwiec P.
Current capacity for endoscopic colorectal cancer screening in the United States: data
from the National Cancer Institute Survey of Colorectal Cancer
Screening Practices. Am J Med 2003;115(2):129-33.
- Klabunde CN, Frame PS, Meadow A, Jones E, Nadel M, Vernon
SW. A national survey of primary care physicians' colorectal
cancer screening recommendations and practices. Prev Med
- Wexner SD, Litwin D, Cohen J, Earle D, Ferzli G, Flaherty
J, et al.
Principles of privileging and credentialing for
endoscopy and colonoscopy. Gastrointest Endosc
- New Mexico Health Policy Commission. Health Care in New
Mexico. Access, Financing, Delivery and Outcomes. Santa Fe (NM): The Commission;
- Lieberman DA, Ghormley JM.
Physician assistants in
gastroenterology: should they perform endoscopy? Am J Gastroenterol 1992;87:940-3.
- Salem N. Poll: 21% N.M. doctors want out of state system.
Albuquerque (NM): Albuquerque Tribune; 2000 Jan 27.
- Mysliwiec PA, Brown ML, Klabunde CN, Ransohoff DF.
physicians doing too much colonoscopy? A national survey of
colorectal surveillance after polypectomy. Ann Intern Med
- Sonnenberg A, Delco F.
Cost-effectiveness of a single
colonoscopy in screening for colorectal cancer. Arch Intern Med
Back to top