Does the Varying Rate of Failed Colonoscopy by Provider Create Additional Charges to the
Patient?
Matthew Nguyen
A thesis submitted in partial fulfillment of the requirements for the degree of
Master in Public Health
University of Washington
2012
Program Authorized to Offer Degree:
School of Public Health – Health Services
University of Washington
Abstract
Does the Varying Rate of Failed Colonoscopy by Provider Create Additional Charges to the
Patient?
Matthew Nguyen
Chair of the Supervisory Committee:
Research Professor, Charles Maynard, PhD, Clinical Faculty, Otto Lin, MD
Health Services
Background: The failure of an endoscopist to thoroughly visualize the colon during a
colonoscopy will often result in a repeat procedure to ensure proper screening,
surveillance, and/or treatment. We believe that the rates of failed colonoscopies and
subsequent follow-up procedures will vary by individual endoscopist and contribute
extra charges to the patient. Out study has two objectives: 1) To determine if
endoscopists have varying rates of failed colonoscopies, 2) To determine if endoscopists
have varying rates of early repeat follow-up procedures after failed colonoscopies.
Methods: We retrospectively reviewed 6,000 colonoscopies performed from 2009 –
2011 at Virginia Mason Medical Center. Based on the abstracted information, we
determined whether each procedure was a success or failure. For failed procedures, we
determined whether a repeat procedure was recommended and how soon after the
failed procedure was the repeat procedure recommended. Of failed colonoscopies with
a recommended early follow-up procedure, we determined those that contributed extra
charges to the patient.
Results: We found one endoscopist with high odds of performing failed colonoscopies, but
he or she did not have high odds of recommending a follow-up interval that would contribute
to extra charges. We also found one endoscopist with high odds of recommending a followup interval that would contribute extra charges, but he or she did not have high odds of
performing a failed colonoscopy.
Conclusions: Our results indicate no one individual provider could be held responsible
for extra charges assigned to the patient due to failed colonoscopies. While the total
burden of extra charges as a result of failed colonoscopies may be deemed excessive by
some, any measures aimed to decrease those excess charges should be addressed more
broadly to all physicians and patients.
LIST OF TABLES
Table Number
Page
1. Patient Characteristics……………………………………….... 13
2. Classification of Patients by Clinical Indication or Findings……. 14
3. Odds ratios and 95% confidence intervals of failure type and recommendation
for repeat procedure by endoscopist……………………………. 15
Page I
1
Does the Varying Rate of Failed Colonoscopy by Provider Create Additional Charges to the
Patient?
Introduction
To address the rapidly increasing cost of healthcare, many healthcare spending
reforms have been centered on minimizing unnecessary medical procedures. These reforms
have been aimed towards some of the more prolific medical procedures. One of the most
prolific medical procedures in the United States is the colonoscopy (1). The colonoscopy is
one of the primary procedures used by gastroenterologists in the United States for screening,
surveying, and providing therapeutic services for colonic diseases and anomalies – including
colorectal cancer, inflammatory bowel disease, and polyps. With more than 14 million
colonoscopies performed annually in the United States and expectations that usage rates will
only increase, attention should focus on limiting those colonoscopy procedures which are
clinically unnecessary (1). We hypothesize that the rate of failed colonoscopies differs by
individual endoscopists. We predict that this variance will result in higher rates of follow-up
procedures that result in unnecessary charges to the patient. We therefore performed a
retrospective chart review study to determine whether failed colonoscopies rates differ
between providers and, if so, whether they contribute extra fiscal charges for the patient.
Background
One aspect of a successful colonoscopy is cecal intubation – the visualization of the
cecum -- in the proximal colon by the endoscopist. Previous studies have found that a
2
significant percentage of colonic lesions do appear near and/or within the cecum, thus failure
to reach that area will often require additional screening methods such as a CT colonoscopy
or a repeat colonoscopy (2). The U.S. Multi-Society Task Force recommends that cecal
intubation be achieved in more than 90% of all colonoscopy procedures (3). Failure to
visualize the cecum can occur for a variety of reasons, including inadequate patient bowel
preparation, endoscopist inexperience, endoscopist low ability level, and colon anatomy (49). Specifically, in regards to patient bowel preparation, the endoscopist evaluates each
patient’s bowel preparation on a three-level scale. A successful bowel preparation allows the
endoscopist to accurately visualize the entire colon. A mediocre or inadequate bowel
preparation will allow the endoscopist to visualize the majority of the colon, but smaller
polyps and/or other lesions may be missed. A completely failed colonoscopy due to improper
bowel preparation occurs when the endoscopist cannot advance the endoscope towards the
cecum in the right colon due to bowel materials blocking the endoscope. Even with these
standards, ultimately the judgment of each patient’s bowel preparation is a subjective process
determined by the individual provider.
A failed colonoscopy will likely be followed with a recommendation for a repeat
colonoscopy procedure. There are currently no universally accepted guidelines regarding the
recommended length of time between a failed colonoscopy and a subsequent follow-up
procedure. Also, very little is known about the financial implications of a failed colonoscopy
procedure. Rex et al. concluded that failed colonoscopies due to bowel preparation in 2
medical centers resulted in a 12 – 22% increase in charges over one-year period (10). Extra
3
charges were summed by estimating additional charges associated with a recommendation to
have a repeat procedure at an interval shorter than that specified by practice guidelines. This
method may overestimate charges, since not all repeat colonoscopies will result in extra
charges for the patient and medical facility. A repeat colonoscopy at a quicker interval than
the suggested guidelines does not always result in an extra procedure – and charges – over
the lifetime of a patient.
Methods
The institutional Review Board at Virginia Mason Medical Center (VMMC) gave
approval for this retrospective chart review study and individual informed consent was not
required.
Subject Recruitment and Databases
VMMC is a health care system located in Seattle, Washington with 14
gastroenterologists performing more than 14,000 colonoscopies annually. Study patients
undergoing colonoscopy were identified from the medical center’s financial database
(WebFocus, Information Builders, New York, NY) using the following procedure codes from
the Current Procedural Terminology): 45386, 45385, 45384, 45382, 45381, 45380, 44388
, 44389 , 44390, 44391, 44392, 44393, 44394, 44397, 45378 , 45379. We extracted
colonoscopy procedure data from January 1st, 2010, through July 1st, 2011. Our sample did
not include every colonoscopy procedure performed at VMMC during this period. For every
6-month period starting from January 1st, 2010, we identified the first 200 colonoscopies
4
performed by 8 of the 14 gastroenterologists. These 8 gastroenterologists were identified as
performing a “significant” number of colonoscopies – on average 200 or more colonoscopies
every 6 months. The sample was limited to these 8 gastroenterologists in order to accurately
assess the abilities of those providers that regularly performed colonoscopies. Studies have
shown that gastroenterologists who perform low volumes of colonoscopies have higher rates
of incomplete colonoscopies, a fact that was considered in our conclusions (8 - 9).
For each of the colonoscopy procedures, we thoroughly reviewed the electronic
medical records at VMMC (Cerner Information Systems, Kansas City, Missouri) -- including
clinic notes, procedure notes, pathology reports, history and physicals, and consultations. We
personally abstracted data from the medical records into a database. For the purpose of our
study, any patient receiving a colonoscopy at VMMC during the study period is an eligible
study participant, regardless of indication of the index procedure, gender, age, colonoscopy
findings, or any other criteria.
Using a standardized data input form, we recorded the following data points: 1)
indication for colonoscopy procedure, 2) clinical findings, 3) patient bowel preparation, 4)
cecal visualization by the endoscopist, 5) if cecum visualization was not achieved, detailed
reasons for this, 6) if cecum visualization was not achieved or if bowel preparation was not
adequate, the recommended follow-up procedure, and 7) if cecal visualization was not
achieved or if bowel preparation was not adequate, the recommended follow-up time interval
for a repeat procedure. Failed colonoscopies were those in which the colonoscopy exam was
5
attempted but cecal visualization by the endoscopist did not occur or those in which the
colonoscopy exam was completed but a thorough examination of the majority of the colon
was deemed incomplete by the endoscopist due to inadequate bowel preparation by the
patient. We did not collect the actual follow-up procedure and interval data since the vast
majority of the follow-up procedures were not scheduled to occur until after completion of
this study. Instead, we collected data on the recommended interval for follow-up given by the
endoscopist after a failed colonoscopy.
Colonoscopies were categorized according to indications and clinical findings. Each
group of colonoscopies was assigned a recommended follow-up colonoscopy time interval
that was based on the existing literature and guidelines set by the major gastroenterology
groups: American Society of Gastrointestinal Endoscopy (ASGE), American
Gastroenterological Association (AGA) and American College of Gastroenterology (ACG)
(11 – 13). The assigned recommended follow-up colonoscopy time interval is initially based
on each individual patient’s original indication for receiving a colonoscopy procedure. A
more aggressive recommended follow-up colonoscopy time interval would be assigned if a
patient had any type of clinical finding during the colonoscopy that would require a quicker
follow-up. For example, if a patient -- with no prior personal or family history of polyps
and/or colorectal cancer -- came in for a screening colonoscopy, the recommended follow-up
colonoscopy time interval – given the absence of any significant clinical findings – would be
10 years. If a different patient with an identical indication received a colonoscopy, but had an
6
adenoma removed during the procedure, the recommended follow-up colonoscopy time
interval would be 5 years.
Estimation of Charges
Colonoscopy charge data were obtained from local Medicare-allowable hospitalbased fees. A standard colonoscopy with biopsy in the Seattle / King County region of
Washington State had an average Medicare charge of $783. We used Medicare charge
instead of received payments or procedural costs for the following reasons: First, the majority
of the recommended follow-up procedures had yet to occur at the time of our study. As a
result, we could not collect received payment or procedural cost data. Second, received
payments and/or procedural costs at VMMC may not be applicable to other medical
facilities. Calculating an estimate using a standardized Medicare charge will permit
comparison of our experience with that of other institution.
Statistical Methods
We utilized multiple logistic regression to determine each endoscopist’s 1) overall
rate of failed colonoscopy, 2) rate of failed colonoscopy due to patient bowel preparation, 3)
rate of failed colonoscopy due to reasons other than patient bowel preparation, and 3) rate in
which a follow-up interval recommendation after a failed colonoscopy was less than or equal
to one-half of the recommended follow-up interval for a successful colonoscopy. We
controlled for the following potential confounders: patient age, gender, and clinical
indication for the colonoscopy.
7
Results
Study Population
A total of 6,000 unique colonoscopy procedures were identified through the
colonoscopy completion rate quality metrics database. The overall mean age was 59 years
(range 16-95); 2910 (48%) were male (Table 1).Table 2 details the clinical indications or the
findings for each procedure – a patient was grouped into a finding category if the clinical
findings for that particular procedure resulted in a follow-up interval that was shorter than it
would have been with the original procedural indication. Table 2 also shows the
recommended follow-up colonoscopy time interval given a successful procedure.
Failed Colonoscopy Rates by Endoscopist
According to our study criteria, 550 (9. %) procedures resulted in an incomplete
colonoscopy. 48 (0.8%) patients received an incomplete colonoscopy for reasons not
involving patient bowel preparation. 481 (8. %) patients were described as having a failed
colonoscopy due to mediocre or inadequate bowel preparation -- meaning that the
endoscopist was able to visualize the cecum, but due to residual fecal matter in the colon,
was not able to thoroughly inspect the entire colon. 27 (0.4%) had a completely inadequate
bowel preparation in which the endoscopist could not visualize the cecum due to residual
fecal matter completely obstructing visualization or movement of the endoscope.
8
Each of the 550 failed procedures was given a subsequent follow-up interval. 373 (6.
%) were advised to have a follow-up procedure in a shorter period of time than the
recommended follow-up procedure time if the procedure were successful. Altogether, 312
(5%) were given a follow-up interval that was shorter than one-half of the guideline
recommended follow-up time interval. We decided to use one-half of the standard follow-up
time interval as a benchmark to ensure simplicity and also to prevent overestimating the costs
of failed colonoscopies. Even though a provider may have recommended a shorter follow-up
interval after a failed colonoscopy, extra procedures – and charges -- may not necessarily
have been accrued. For example, a 50 year old patient, who undergoes a failed screening
colonoscopy, is advised to have a follow-up procedure in 7 years instead of 10 years as
recommended for successful colonoscopies. Will this forward-shifted procedure result in an
extra procedure (and charges) over the lifetime of a patient? We argue that it will not. Shorter
than recommended intervals will only result in shifting the costs of colonoscopies over a
patient’s lifespan forward, rather than adding to the total cost.
While we must emphasize that this one-half threshold is an arbitrary benchmark, we
feel that it will provide a rough approximation of which failed colonoscopies will result in
repeated procedures.
Table 3 shows the risk adjusted odds of various types of failed procedures by
operator. Regarding the rate of any type of failed colonoscopy, only one endoscopist
(Endoscopist “G”) had an odds ratio greater than one that was statistically significant. The
9
odds of Endoscopist “G” performing a failed colonoscopy, after controlling for patient age,
gender, and clinical indication, was1.4 times higher than endoscopist I, the reference
category. Regarding the rate of recommending a follow-up procedure after a failed
colonoscopy at one-half or less of the guideline recommended follow-up interval, only one
endoscopist (Endoscopist “H”) had an odds ratio greater than one. The odds of Endoscopist
“H” recommending a follow-up procedure after a failed colonoscopy at one-half or less of
the guideline recommended follow-up interval was 2.9 times higher than endoscopist I.
However, in regards to their rate of performing a failed colonoscopy, Endoscopist “H” had a
much lower odds of performing a failed procedure. This rate was statistically significant (p <
0.001). Endoscopist “G”, who had a statistically significant higher odds of performing a
failed colonoscopy than operator I, had a lower odds ratio of recommending a follow-up
procedure after a failed colonoscopy at one-half or less of the guideline recommended
follow-up interval. However, this rate was not statistically significant (p= 0.06).
Estimation of Extra Charges due to Failed Colonoscopies
Using a standardized Medicare charge ($783) for colonoscopies in the Seattle / King
County area, the failed colonoscopies with significantly shorter recommended time intervals
contributed an estimated $244,296.00 in extra charges.
Discussion
In summary, 5% of all the studied colonoscopies were given a recommended followup time interval that resulted in extra procedures and costs. This estimate is much lower
10
when compared to a previous study by Rex et al. who found a 12-22% increase in costs (8).
More importantly, we only found one endoscopist with a statistically significant increased
likelihood of performing failed colonoscopies. Furthermore this endoscopist did not have
high odds of recommending a follow-up procedure that resulted in extra procedures and
charges. The only endoscopist that was found to have high odds of recommending extra
procedures also had very low odds of performing failed ones. As a result, we argue that this
endoscopist also did not contribute extra procedures or charges.
Any unnecessary medical procedure presents certain risks and costs to the patient.
However, our findings suggest while failed colonoscopies may lead to repeat procedures and
consequently, increased charges to the patient, the rate at which they occur cannot be traced
to any individual provider. While we found one endoscopist with high odds of performing
failed colonoscopies, he or she did not have high odds of recommending a follow-up interval
that would contribute to extra charges. Conversely, we found one endoscopist with high odds
of recommending a follow-up interval that would contribute extra charges, but he or she did
not have high odds of performing a failed colonoscopy. We conclude that efforts within the
participating study facility to lower healthcare charges should not be focused on individual
provider patterns of failed colonoscopies or on the rates of recommending follow-up
colonoscopies that produce extra procedures and charges. Rather efforts should be focused
on all providers and all patients.
11
We did estimate that, within a 3 year period, nearly a quarter-million dollars was charged
to our patients due to failed colonoscopies with short recommended follow-up time intervals.
Our findings suggest that if efforts are to be made to decrease this estimate in future years,
the focus should be pointed towards broad-based methods that encompass all endoscopists
and patients.
Our study has several limitations. First, our sample may not be representative of all
medical systems performing colonoscopies. VMMC performs a high-volume of
colonoscopies and the performing endoscopists are highly trained and experienced. Lowvolume medical systems with less experienced endoscopists may have higher rates of failed
colonoscopies. Our findings may not be applicable to these situations. Second, in estimating
a total charge amount due to failed colonoscopies, our study did not completely capture the
cost of a colonoscopy procedure. We decided to use one standardized Medicare charge for a
colonoscopy performed in the Seattle/ King County area. Additional charges, such as
professional provider charges, supportive nursing charges, administrative charges, etc. were
not calculated. Our resulting calculations should not be mistaken for a specific, realistic
estimation of the extra charges due to failed colonoscopies. Instead, the primary take-away
from this study should be the discrepancies in the rate of inadequate bowel preparations
between providers and also the differences between providers in the rate at which they
recommended their patients to return for a follow-up colonoscopy. A more complete estimate
of the cost of failed colonoscopies may be more persuasive in initiating action to lower the
rate of failure. Furthermore, in calculating the rate at which repeat procedures were
12
recommended, we used an arbitrary, conservative threshold that may have underestimated
the levels at which unnecessary procedures are recommended. Again, a more liberal
threshold may have provided a more persuasive argument to initiate action.
We conclude that extra charges associated with failed colonoscopies were not
associated with endoscopists’ rates of failure or recommendations for repeat procedures. .
We estimated that failed colonoscopies contributed more than $240,000 in extra charges to
patients in this single institution. However, further studies comparing estimates of
departmental level charges from failed colonoscopies to charges for other costly, unnecessary
procedures will be required to inform decision making regarding where limited resources
should be given to reduce rates of failed medical procedures.
13
Table 1. Patient characteristics
Age (years)
Female
Male
Bowel Preparation
Failed
Mediocre
Not Stated
OK
59+12
3090
2910
52 %
48%
27
481
248
5244
0.5%
9%
3%
87%
14
Table 2. Classification of clinical indication or findings.
Findings
Non-Advanced
Adenoma(s)
Advanced
Adenoma(s)
Cancer
Hyperplastic Polyp(s)
Mass
Diagnostic
Screening – 1st
Degree Family
History of Colorectal
Cancer
Screening – 2nd
Degree Family
History of Colorectal
Cancer
Screening - NO
Family History
Screening – 1st
Degree Family
History of Polyps
Screening – 2nd
Degree Family
History of Polyps
Surveillance - Cancer
Surveillance –
inflammatory bowel
disease
Surveillance - Mass
Surveillance – Other*
Surveillance – Polyps
Unknown
Patient with Clinical Findings (n=1683)
Total
%
Recommended F/U Interval
727
12.1%
4 (3-5)
478
8.0%
3
41
0.7%
1
408
6.8%
10
29
0.5%
1
Patients with No Clinical Findings (n=4317)
Age Dependent (10 for those >=
1126
18.8%
50, or 50 – Age)
318
5.3%
4 (3-5)
77
1.3%
10
1481
24.7%
10
138
2.3%
5
1
95
0.02%
1.6%
10
1
137
12
48
874
2.3%
0.2%
0.8%
14.6%
10
0.2%
3
1
4 (3-5)
4 (3-5)
Age Dependent (10 for those >=
50, or 50 – Age)
15
Table 3. Odds ratios and 95% confidence intervals of failure type and recommendation for
repeat procedure by endoscopist
Endoscopi Failed - Bowel
st
Prep and Failed
A
0.63 (0.44- .90)*
(n=600)
Failed - Bowel
Prep Related
Failed - Not Bowel
FU @ 1/2 of
Prep Related
Recommendation
0.62 (0.43 0.89)*
0.96 (0.31 - 2.99)
0.24 (0.10 - 0.57)*
0.26 (0.17 - 0.40)*
0.24 (0.15 0.38)*
0.75 (0.24 - 2.33)
0.72 (0.29 - 1.79)
0.61 (0.42 - 0.89)*
0.52 (0.35 0.77)*
1.89 (0.72 - 4.97)
0.81 (0.38 - 1.71)
0.82 (0.61 - 1.12) 0.83 (0.60 - 1.13)
0.82 (0.28 - 2.41)
1.41 (0.76 - 2.62)
1.15 (0.86 - 1.53) 1.11 (0.82 - 1.50)
1.87 (0.73 - 4.75)
1.67 (0.94 - 2.95)
0.33 (0.21 - 0.50)* 0.3 (0.19 - 0.47)*
0.68 (0.20 - 2.29)
0.97 (0.41 - 2.31)
B
(n=806)
C
(n=533)
D
(n=805)
E
(n=807)
F
(n=613)
G
1.43 (1.03 - 20)*
1.39 (0.98 - 1.96)
2.16 (0.79 - 5.92)
0.53 (0.27 - 1.03)
0.26 (0.16 - 0.41)*
0.25 (0.15 0.40)*
0.86 (0.25 - 2.90)
2.78 (1.03 - 7.54)*
-
-
-
-
(n=407)
H
(n=608)
I (reference
group)
16
(n=821)
P <0.05
1
List of References
1. Seeff, L. C., Richards, T. B., Shapiro, J. A., Nadel, M. R., Manninen, D. L., Given, L. S.,
Dong, F. B., et al. (2004). How many endoscopies are performed for colorectal cancer
screening? Results from CDC’s survey of endoscopic capacity. Gastroenterology,
127(6), 1670-1677.
2. Anderson, J. C., Gonzalez, J. D., Messina, C. R., & Pollack, B. J. (2000). Factors that
predict incomplete colonoscopy: thinner is not always better. The American journal
of gastroenterology, 95(10), 2784–2787.
3. Froehlich, F., Wietlisbach, V., Gonvers, J. J., Burnand, B., & Vader, J. P. (2005). Impact
of colonic cleansing on quality and diagnostic yield of colonoscopy: the European
Panel of Appropriateness of Gastrointestinal Endoscopy European multicenter study.
Gastrointestinal endoscopy, 61(3), 378–384.
4. Hanson, M. E., Pickhardt, P. J., Kim, D. H., & Pfau, P. R. (2007). Anatomic factors
predictive of incomplete colonoscopy based on findings at CT colonography.
American Journal of Roentgenology, 189(4), 774–779.
5. Hazewinkel, Y., & Dekker, E. (2011). Colonoscopy: basic principles and novel techniques.
Nat Rev Gastroenterol Hepatol, 8(10), 554-564. doi:10.1038/nrgastro.2011.141
6. Imperiale, T. F., Wagner, D. R., Lin, C. Y., Larkin, G. N., Rogge, J. D., & Ransohoff, D.
F. (2000). Risk of advanced proximal neoplasms in asymptomatic adults according to
the distal colorectal findings. New England journal of medicine, 343(3), 169–174.
2
7. Lee, S.-H., Chung, I.-K., Kim, S.-J., Kim, J.-O., Ko, B.-M., Hwangbo, Y., Kim, W. H., et
al. (2008). An adequate level of training for technical competence in screening and
diagnostic colonoscopy: a prospective multicenter evaluation of the learning curve.
Gastrointestinal Endoscopy, 67(4), 683-689. doi:10.1016/j.gie.2007.10.018
7. Lieberman, D. A., Weiss, D. G., Bond, J. H., Ahnen, D. J., Garewal, H., Harford, W. V.,
Provenzale, D., et al. (2000). Use of colonoscopy to screen asymptomatic adults for
colorectal cancer. New England Journal of Medicine, 343(3), 162–168.
8. Shah, H. A., Paszat, L. F., Saskin, R., Stukel, T. A., & Rabeneck, L. (2007). Factors
associated with incomplete colonoscopy: a population-based study. Gastroenterology,
132(7), 2297–2303.
9. Rex, D. K., Bond, J. H., Winawer, S., Levin, T. R., Burt, R. W., Johnson, D. A., Kirk, L.
M., et al. (2002). Quality in the technical performance of colonoscopy and the
continuous quality improvement process for colonoscopy: recommendations of the U.
S. Multi-Society Task Force on Colorectal Cancer. The American journal of
gastroenterology, 97(6), 1296–1308.
10. Rex, D. K., Imperiale, T. F., Latinovich, D. R., & Bratcher, L. L. (2002). Impact of bowel
preparation on efficiency and cost of colonoscopy. The American journal of
gastroenterology, 97(7), 1696–1700.
11. Keren, D., Rainis, T., Goldstein, O., Stermer, E., & Lavy, A. (2008b). Significant Colonic
Neoplasia Prevalence and ASGE Recommendations: Is it time for a Change? Journal
of clinical gastroenterology, 42(8), 886.
3
12.Rex, D. K., Johnson, D. A., Anderson, J. C., Schoenfeld, P. S., Burke, C. A., & Inadomi,
J. M. (2009). American College of Gastroenterology Guidelines for Colorectal
Cancer Screening 2008. Am J Gastroenterol, 104(3), 739-750.
13. Winawer, S. (2003). Colorectal cancer screening and surveillance: Clinical guidelines
and rationale? Update based on new evidence. Gastroenterology, 124(2), 544-560.
doi:10.1053/gast.2003.50044