(Circulation. 1997;95:2485.)
© 1997 American Heart Association, Inc.
Articles |
Relationship Between Physician and Hospital Coronary Angioplasty Volume and Outcome in Elderly Patients
From the Outcomes Research and Assessment Group, Duke Clinical Research Institute (J.G.J., E.D.P., C.L.N., J.A.S., E.R.D., L.H.M., D.B.M.), the Department of Medicine (J.G.J., E.D.P., C.L.N., J.A.S., D.B.M.), and the Department of Surgery (L.H.M.), Duke University Medical Center, Durham, NC.
Correspondence to James G. Jollis, MD, Box 3254, Duke University Medical Center, Durham, NC 27710.
Abstract
Background With the expectation that physicians who perform larger numbers of coronary angioplasty procedures will have better outcomes, the American College of Cardiology/American Heart Association guidelines recommend minimum physician volumes of 75 procedures per year. However, there is little empirical data to support this recommendation.
Methods and Results We examined in-hospital bypass surgery and death after angioplasty according to 1992 physician and hospital Medicare procedure volume. In 1992, 6115 physicians performed angioplasty on 97 478 Medicare patients at 984 hospitals. The median numbers of procedures performed per physician and per hospital were 13 (interquartile range, 5 to 25) and 98 (interquartile range, 40 to 181), respectively. With the assumption that Medicare patients composed one half to one third of all patients undergoing angioplasty, these median values are consistent with an overall physician volume of 26 to 39 cases per year and an overall hospital volume of 196 to 294 cases per year. After adjusting for age, sex, race, acute myocardial infarction, and comorbidity, low-volume physicians were associated with higher rates of bypass surgery (P<.001) and low-volume hospitals were associated with higher rates of bypass surgery and death (P<.001). Improving outcomes were seen up to threshold values of 75 Medicare cases per physician and 200 Medicare cases per hospital.
Conclusions More than 50% of physicians and 25% of hospitals performing coronary angioplasty in 1992 were unlikely to have met the minimum volume guidelines first published in 1988, and these patients had worse outcomes. While more recent data are required to determine whether the same relationships persist after the introduction of newer technologies, this study suggests that adherence to minimum volume standards by physicians and hospitals will lead to better outcomes for elderly patients undergoing coronary angioplasty.
Key Words: angioplasty • morbidity • bypass • mortality
Previous studies have found that hospitals that perform higher numbers of coronary angioplasty procedures have lower complication and mortality rates.1 2 3 With the expectation that physicians and hospitals with more angioplasty experience should also have improved outcomes, the American College of Cardiology/American Heart Association (ACC/AHA) guidelines for angioplasty released in 1988 recommended minimum physician volumes of 50 coronary angioplasty procedures per year per physician and 200 procedures per hospital.4 In 1993, the number of recommended procedures for physicians was increased to 75 procedures.5 While there is growing evidence in the literature to support hospital volume requirements, there is little empirical support for physician volume standards.6 We examined the relationship between physician volume and outcome in Medicare patients undergoing angioplasty in 1992, the first year that physician volume could be calculated on the basis of the Unique Physician Identification Number. The Medicare population represented 95% of elderly Americans undergoing angioplasty during the time period.7
Methods
Data Sources
The Medicare National Claims History file consists of both Part
A (hospital) and Part B (physician and outpatient) claims. Part A
claims contain demographic and limited clinical information on all
inpatient hospitalizations that were billed to Medicare, including the
patient’s Health Insurance Claims (HIC) number, age, sex, race,
discharge status including death, up to 10 discharge diagnoses and 6
procedures identified by International Classification of Diseases (ICD)
codes, and attending physician according to Unique Physician
Identification Number.8 Part B claims contain demographic
and limited clinical information from physician and outpatient bills to
Medicare, including HIC number, service or procedure provided according
to Current Procedural Terminology (CPT) codes, and billing physician
according to Unique Physician Identification Number.9 We
excluded from the analyses patients eligible for Medicare for
reasons other than age (end-stage renal disease, Railroad Retirement
Board, and disability entitlements) and patients treated in Federal and
non-US hospitals. Mortality after discharge was obtained from Medicare
Provider Analysis and Review files maintained by the Health
Care Financing Administration (HCFA) by matching HIC number.
Patient Population
Our study population consisted of all Medicare enrollees 65
years of age and over with physician and hospital claims involving
coronary angioplasty in 1992. For each patient, a longitudinal
record of hospitalizations, procedures, and death was created,
linked by the patient’s HIC number. To avoid counting patients more
than once, only the first hospitalization for coronary
angioplasty in 1992 was analyzed in the bypass surgery and
mortality comparisons.
Physician and Hospital Volume Calculations
We used Medicare Part B physician claims for coronary
angioplasty to identify the physician associated with the procedure.
Physician angioplasty volume was calculated by counting all claims for
CPT code 92982 (percutaneous coronary
angioplasty, initial vessel) submitted in 1992, including multiple
procedures per day per patient. The procedure physician was identified
according to the Unique Physician Identification Number submitted with
the procedure claim. Claims associated with physician specialties other
than cardiology or internal medicine were considered to
represent coding errors and were excluded from the
analyses. Hospital angioplasty volume was calculated by
counting all Medicare Part A hospital claims containing an ICD code for
coronary angioplasty (36.01, 36.02, or 36.05) in 1992 for each
hospital according to the method of our previous hospital volume
study.2 Kato and colleagues10 found that
Medicare hospital volume was highly correlated with overall hospital
volume (r2=.89, P<.001) for 109
hospitals in California, with Medicare cases representing
35% of overall hospital angioplasty volume.
Other Study Variables
Coronary bypass surgery performed from the day of
angioplasty until discharge was counted as surgery after unsuccessful
angioplasty. By linking hospital records, patients who transferred
to other hospitals for coronary bypass surgery during the same
admission were identified. Patients were designated as having an acute
myocardial infarction admission if the first record of the initial
hospital encounter contained a primary diagnosis of acute myocardial
infarction (ICD code 410) or a secondary diagnosis of acute myocardial
infarction and a primary diagnosis of an infarction complication such
as papillary muscle rupture (ICD code 429.6), the last record for
the encounter contained a 410 diagnosis code, and the length of stay
for the encounter was at least 3 days if the patient was discharged
alive.11 Claims identified as involving a subsequent
hospitalization for the acute myocardial infarction according to the
fifth digit of the ICD code (410.x2) were excluded from this
classification. The medical school affiliations of hospitals were
identified by Medicare provider-of-services files as "major,"
"limited," "graduate," or "no affiliation."
Data Analysis
The primary outcome of the study was in-hospital bypass surgery
or death. For the initial comparisons according to physician and
hospital volume, patients were grouped by deciles according to the
annual Medicare angioplasty volume of their associated physician or
hospital. Tables comparing outcomes were generated for low-volume (<25
annual procedures), medium-volume (25 to 50 annual procedures), and
high-volume (>50 annual procedures) physicians after stratifying for
patient characteristics including sex, race, age, acute myocardial
infarction, number of vessels undergoing angioplasty, and hospital
characteristics including hospital volume and medical school
affiliation. The boundaries for physician volumes were selected to
represent distinct physician groups based on the decile plots
and to match published volume guidelines.4 Similar
comparisons were made for hospital volume strata.
Logistic regression models were developed to examine the relationship between angioplasty volume and the combined end point of bypass surgery or death after adjusting for patient-specific variables including age, sex, race, acute myocardial infarction, and comorbidity according to the Charlson index.12 Independent variables were transformed to maintain a linear relationship to the dependent variable where appropriate. Additional models examined the relationship between physician and hospital angioplasty volume and in-hospital death.
Results
During 1992, 97 478 Medicare patients underwent 119 886
angioplasty procedures according to physician claims. The mean age of
the patients was 72.6 years (interquartile range, 66 to 78), 44% were
women, and the race distribution was 93.4% white, 3.4% African
American, and 3.2% other or unknown. Patient characteristics by
physician and hospital volume categories are displayed in Table 1
. Patients treated by low-volume providers
were younger, had less comorbid illness, were less likely to undergo
multivessel procedures, and were more likely to be hospitalized with an
acute myocardial infarction.
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According to Medicare Part B claims, there were 6115 physicians who
performed coronary angioplasty in 1992, with annual volumes
ranging from 1 to 494 Medicare procedures (Fig 1). The
median Medicare procedure volume per physician was 13 (interquartile
range, 5 to 25). With the assumption that Medicare patients made up one
half to one third of all patients undergoing angioplasty at the time,
13 Medicare procedures is consistent with an overall procedure
volume of 26 to 39 cases per year.10 According to Medicare
Part A claims, 984 hospitals performed angioplasty in 1992 compared
with 934 hospitals performing angioplasty in 1990 (Fig 2).2 The median number of
Medicare procedures performed per hospital was 98 (interquartile range,
40 to 181), with a range of 1 to 1209 procedures. Assuming the same
proportion of Medicare patients as above, a median of 98 Medicare cases
is consistent with an overall hospital volume of 196 to 294
cases per year.
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The rates of in-hospital bypass surgery, in-hospital death, and the
combined end point of in-hospital bypass surgery or death were 3.3%,
2.5%, and 5.5%, respectively (Table 2). Outcomes by
physician and hospital angioplasty volume are plotted in Figs 3 and 4,
with each point representing 
9700
patients. In-hospital death declined with
increasing hospital volume but did not change with physician volume.
In-hospital bypass surgery and the combined end point of bypass surgery
or death declined with both increasing physician and hospital
angioplasty volumes. Stratifying by physician and hospital volume, the
combined end point of bypass surgery or death was greatest for patients
treated by low-volume physicians in low-volume hospitals and lowest for
patients treated by high-volume physicians in high-volume hospitals
(Table 3).
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After adjustment for age, sex, race, acute myocardial infarction, comorbid illness, and hospital volume to the extent possible with claims data, higher physician volume continued to be strongly associated with decreasing rates of in-hospital bypass surgery or death, mostly attributable to the decline inbypass surgery (P<.001). Improving outcomes were seen up to annual physician Medicare angioplasty volumes of 75 cases per year. This inflection point is consistent with an overall physician angioplasty volume of 150 to 225 cases per year. The logistic regression model with in-hospital death as the dependent variable did not detect a relationship between physician angioplasty volume and in-hospital death. If sufficient illness severity data were available to fully balance comparisons, the study had a 90% chance of detecting an absolute mortality increase of 0.4% for low-volume physicians (<25 annual procedures). Given the limitations of Medicare claims, a mortality difference was more likely to have gone undetected because of an inability to entirely account for illness severity rather than an insufficient number of patients.13
After adjustment for age, sex, race, acute myocardial infarction, comorbid illness, and physician volume, hospital volume was inversely associated with both in-hospital death (P<.001) and the combined end point of in-hospital bypass surgery or death (P<.001), with improving outcomes seen in up to 200 annual Medicare cases, attributable to both the decline in bypass surgery and death. This inflection point is consistent with an overall hospital volume of 400 to 600 cases per year, assuming the same proportion of patients <65 years of age as above. Interaction terms for physician and hospital volume were not significant.
Discussion
The principal findings of this study are that more than 50% of physicians and 25% of hospitals performing coronary angioplasty in 1992 were unlikely to have met the ACC/AHA minimum volume guidelines published in 1988, and patients treated by these low-volume providers had worse outcomes.4 Low-volume physicians were associated with higher rates of bypass surgery, and low-volume hospitals were associated with higher rates of both bypass surgery and death. This is the largest study to date examining the relationship between physician volume and outcome and one of the first to provide empirical evidence in support of the expert consensus ACC/AHA guidelines for minimum physician volume standards.
The higher rate of bypass surgery associated with low-volume physicians observed in this study is consistent with the findings of Shook and colleagues6 regarding emergency surgery and resource use according to physician angioplasty volume. Examining 2350 angioplasty procedures at Good Samaritan Hospital in Los Angeles, Shook and colleagues found that low-volume physicians were associated with more complicated postprocedural courses, as reflected by more emergency bypass surgery (P=.005), higher hospital morbidity (P<.001), higher hospital costs (P=.03), and longer length of stay (P=.004). The finding of an inverse relationship between hospital angioplasty volume and the risk of death or bypass surgery is consistent with our previous observations regarding Medicare patients treated between 1987 and 1990.2 Other studies also have observed worse outcomes for low-volume hospitals.1 3
Prevalence of Low-Volume Providers
On the basis of the Medicare experience in 1992, it appears that
physicians and hospitals widely disregarded the minimum hospital volume
guidelines published in 1988. There were 3510 physicians who performed
15 or fewer Medicare procedures and 344 hospitals that performed 60 or
fewer Medicare procedures, and these providers were unlikely to have
attained overall angioplasty volumes of 50 cases per physician and 200
cases per hospital, as recommended by the coronary angioplasty
guidelines. Physicians and hospitals may have chosen to disregard the
minimum volume guidelines because of the lack of supporting evidence
available in 1992. At the time, the only published data in support of
minimum procedure volume involved procedures other than
coronary angioplasty.14 15 16 Health system factors
such as incentives regarding reimbursement for coronary
angioplasty and an increase in the number of physicians trained to
perform coronary angioplasty may have also contributed to the
growth of low-volume hospitals as well as the large number of
low-volume physicians.
Volume-Outcome Relationship
Three hypotheses first proposed by Luft2 16 may
explain the inverse relationship between volume and mortality. First,
greater experience by high-volume providers led to better outcomes-the
"practice makes perfect" theory. Angioplasty requires significant
technical abilities, and it is likely that the increased skill of
high-volume operators in successfully dilating lesions, as well as in
"bailing out" procedures involving abrupt closure, led to the
lower rates of bypass surgery for these providers. The second
hypothesis involves selective referral to high-volume providers. That
is, referring physicians knew which angioplasty providers had better
outcomes, selectively referred more patients to such providers, and
thus these providers performed the highest volume of procedures. In the
absence of published provider outcome data such as are available in New
York State, it was difficult for referring physicians to determine
which physicians and hospitals had better outcomes. To the extent that
angioplasty outcomes correlated with professional reputations, it is
possible that selective referral led to better outcomes for high-volume
providers.
The third possible explanation for the inverse relation between volume and outcome is that differences in patient characteristics led to worse outcomes for low-volume providers. Angioplasty volume continued to be inversely related to in-hospital bypass surgery or death after adjustment for the patient characteristics of age, sex, race, acute myocardial infarction, and comorbidity, according to the Medicare data. However, claims data are substantially limited in their ability to describe the severity of coronary disease as well as comorbid illnesses, and it is likely that the models did not entirely account for illness severity differences among patients.13
More detailed data from two studies that reported coronary
disease severity according to physician procedure volume do not support
the third hypothesis.6 17 Clinical characteristics,
including ACC/AHA lesion severity classification by operator volume,
were reported from the Society for Cardiac Angiography and
Interventions (SCA&I) database for 7747 patients who underwent
angioplasty at 18 hospitals in 1992.17 According to
ACC/AHA classifications, type C lesions are most often associated with
unsuccessful procedures because their characteristics include longer
length, excessive tortuosity of the proximal segment, total occlusion
for >3 months, or location on extremely angulated segments, in
degenerated vein grafts, or by major side branches.4 In
the SCA&I registry, 7.9% of the cases for low-volume (<50 annual
cases) physicians involved type C lesions compared with 14.9% for
higher-volume (
50 annual cases) physicians (P<.001). The
study by Shook involving 2350 angioplasty procedures between March 1991
and February 1994 also found that patients treated by high-volume
operators had greater risk according to older age, more multivessel
procedures, and more emergent/urgent procedures.6 These
data imply that low-volume operators were actually performing
angioplasty on patients with less complex coronary disease
during the study period, making increased coronary disease
severity an unlikely explanation for the worse outcomes for low-volume
physicians. They also raise the possibility that an inverse
relationship between physician volume and mortality was not detected in
Medicare claims because of the lack of illness severity detail.
Impact of Newer Technologies
Since 1992, two treatments have been introduced, coronary
stents and platelet glycoprotein
inhibitors, which have significantly reduced the need for
bypass surgery after angioplasty.18 19 20 21 The relationship
between physician volume and outcome in this study was mainly
attributable to higher rates of bypass surgery, whereas the
relationship between hospital volume and outcome was attributable to
both higher mortality and more surgery. With a decline in the surgical
rate, the relationship between experience and bypass surgery may change
in more contemporary data. However, it does not seem likely that
factors related to worse outcomes by low-volume providers will be
alleviated by platelet inhibitors or stents. The
potential for complications related to the new technologies such as
femoral artery hemorrhage or inability to adequately deploy a
stent would be expected to be greater for inexperienced operators.
Patients who experience abrupt closure and who previously would have
been referred to surgery may now undergo "bail-out" stenting.
More recent data are needed to determine whether the relationship
between angioplasty volume and outcome continues to be observed, with
attention to additional outcomes such as bleeding complications or
emergent stenting.
Implications for Minimum Volume Standards
The observations of this study concerning angioplasty volume and
outcome raise the important policy issue of where to set minimum volume
guidelines. Using logistic regression, we found an inverse relationship
between physician volume and outcome up to Medicare procedure volumes
of 75 cases per year, or an estimated overall physician volume of 150
to 225 cases per year. For hospital volume, improving outcomes were
seen up to 200 Medicare cases per year, or an estimated overall
hospital volume of 400 to 600 cases per year. If low-volume physicians
had achieved the experience and results of higher-volume physicians,
there would have been 545 fewer surgeries at a minimum physician volume
of 25 Medicare cases per year and 2742 fewer surgeries at a minimum
physician volume of 75 Medicare cases per year. For hospitals, there
would have been 124 fewer deaths and 145 fewer surgeries at a minimum
hospital volume of 100 Medicare cases per year and 266 fewer deaths and
411 fewer surgeries at a minimum hospital volume of 200 Medicare cases
per year. However, raising minimum volume requirements to the higher
levels would have diminished access to angioplasty in a substantial
number of settings. Minimum volume requirements for physicians and
hospitals equivalent to 75 and 200 Medicare cases per year,
respectively, would have restricted >95% of physicians and >75% of
hospitals from performing angioplasty in 1992. In setting volume
standards, maintaining reasonable geographic access to angioplasty will
need to be balanced against the improved outcomes available from the
most experienced operators and programs. Access is particularly
important for patients suffering acute myocardial infarction who cannot
be treated with thrombolytic therapy. On the basis of
the Medicare experience of 1992, in which a substantial number of
providers did not appear to adhere to the minimum volume standards,
both an increase in the minimum volume standards and a stricter
adherence to these standards are likely to lead to greatest improvement
in outcome.
Quality Low-Volume Operators
A more basic issue concerning angioplasty guidelines is whether
volume limits should be set at all. The experience of low-volume
providers in this study was considered in the aggregate, yielding
stable estimates of worse outcomes on average for low-volume operators.
Among these low-volume physicians and hospitals, some may have had
better outcomes while others had worse outcomes. As minimum volume
standards would restrict low-volume providers with better outcomes from
practice, some believe that guidelines should focus on the
identification of quality low-volume providers rather than strictly on
volume limits. Confidently identifying such low-volume providers with
better outcomes is difficult because of the "low-volume operator
paradox" suggested by Ellis and colleagues.22 Because
of the small number of procedures that can be examined, outcome
estimates concerning individual low-volume physicians or hospitals are
subject to wide confidence limits. Also, most current observational
angioplasty data are limited in the ability to reliably identify best
practice because of limitations in measuring baseline risk as well as
outcomes.23 Our study suggests that strategies that limit
angioplasty to higher volume providers will improve outcomes. For
occasional situations in which higher-volume providers are not
available and low-volume providers with improved outcomes can be
identified, volume standards may serve as a guideline rather than a
strict cutoff. Such high-quality, low-volume physicians and hospitals
may be identified by combining experience over a number of years to
derive stable estimates of performance.
Incentive to Perform More Procedures
Another concern regarding volume standards is their potential to
encourage unnecessary procedures. To meet the suggested volume targets,
low-volume providers may perform additional procedures for marginal
indications. While volume limits have the potential to encourage some
operators to perform unneeded angioplasty, it is not clear whether the
additional incentive will substantially lower the threshold for
performing angioplasty below levels encouraged by reimbursement in the
current health service system. As managed care and capitated payment
lower reimbursement incentives, the role of volume guidelines in
encouraging unnecessary procedures may become relatively more
important.
Additional Limitations
In addition to the limitations outlined above, several other
limitations to this study should be noted. First, the study involves
patients >65 years of age and may be limited in its applicability to
younger patients. Younger patients would be expected to be less
technically challenging because of coronary disease
characteristics such as a lower prevalence of lesion calcification and
to have lower mortality because of factors such as less comorbid
illness. On the basis of observations in this study and other work
showing that younger patients have lower procedural mortality and
higher rates of bypass surgery, the mortality relationship would be
expected to be diminished in a younger cohort, whereas the bypass
surgery relationship may persist.24 A second limitation
involves our focus on the initial procedure in 1992. While this
approach avoided confounding associated with double-counting the
patients, it also led to underrepresentation of patients
undergoing repeat angioplasty. Second procedures involving patients who
had undergone prior angioplasty in 1991 or earlier were included, but
repeat procedures in 1992 were excluded. Because there are no data
demonstrating that repeat angioplasty carries risks different from
initial angioplasty, the findings were unlikely to have been
substantially altered by a study design that included additional
patients undergoing repeat procedures. A third limitation is that we
only identified one physician per procedure and thus were not able to
examine the impact of multiple physicians per procedure on the volume
outcome relationship.
Conclusions
More than 50% of physicians and 25% of hospitals performing
coronary angioplasty in 1992 were unlikely to have met the
minimum volume guidelines first published in 1988. Elderly patients
treated by these low-volume providers had worse outcomes, manifested by
higher bypass surgery rates for low-volume physicians and higher bypass
surgery and death rates for low-volume hospitals. This
represents the largest study to date providing empirical data
to support minimum angioplasty volume standards for physicians. While
more recent data are required to determine whether the same
relationships persist after the introduction of coronary stents
and glycoprotein IIb/IIIa receptor inhibitors,
this study suggests that adherence to minimum volume standards for
physicians and hospitals will result in better angioplasty outcomes for
elderly Americans.
Acknowledgments
This study was supported by research grants HS-08805 and HS-06503 from the Agency for Health Care Policy and Research, Rockville, Md.
Received February 28, 1997; revision received April 17, 1997; accepted April 18, 1997.
References
1. Ritchie JL, Phillips KA, Luft HS.
Coronary angioplasty: statewide experience in
California. Circulation. 1993;88:2735-2743.
2. Jollis JG, Peterson ED, DeLong ER, Mark DB, Collins
SR, Muhlbaier LH, Pryor DB. The relationship between hospital
volume of coronary angioplasty and short term mortality in
patients over age 65 in the United States. N Engl
J Med. 1994;331:1625-1629.
3. Kimmel SE, Berlin JA, Laskey WK. The
relationship between coronary angioplasty procedure volume and
major complications. JAMA. 1995;274:1137-1142.
4. Ryan TJ, Faxon DP, Gunnar RM, Kennedy JW, King SB, Loop FL, Peterson KL, Reeves TJ, Williams DO, Winters WL. Guidelines for percutaneous transluminal coronary angioplasty. J Am Coll Cardiol. 1988;12:529-545.[Medline] [Order article via Infotrieve]
5. Ryan TJ, Bauman WB, Kennedy JW, Kereiakes DJ, King SB,
McCallister BD, Smith SC, Ullyot DJ. Guidelines for
percutaneous transluminal coronary
angioplasty. Circulation. 1993;88:2987-3007.
6. Shook TL, Sun GW, Burstein S, Eisenhauer AC, Matthews RV. Comparison of percutaneous transluminal coronary angioplasty outcome and hospital costs for low-volume and high-volume operators. Am J Cardiol. 1996;77:331-336.[Medline] [Order article via Infotrieve]
7. May DS, Kelly JJ, Mendlein JM, Garbe PL Surveillance of major causes of hospitalization among the elderly, 1988. MMWR CDC Surveillance Summaries. 1991;40:7-21.
8. International Classification of Diseases, 9th Revision, Clinical Modification. Los Angeles, Calif: Practice Management Information Corp; 1991.
9. Physicians’ Current Procedural Terminology 1994. Chicago, Ill: American Medical Association; 1994.
10. Kato NS, Ergun ME, Carter GM. Health policy implications of volume recommendations on percutaneous transluminal coronary angioplasty in the United States. Circulation 1996;94(suppl I):I-532. Abstract.
11. Annual Report of the California Hospital Outcomes Project. State of California, Office of Statewide Planning and Development; 1993.
12. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies. J Chron Dis. 1987;40:373-383.[Medline] [Order article via Infotrieve]
13. Jollis JG, Ancukiewicz M, DeLong ER, Pryor DB,
Muhlbaier LH, Mark DB. Discordance of databases designed for
claims payment versus clinical information systems: implications for
outcomes research. Ann Intern Med. 1993;119:844-850.
14. Showstack JA, Rosenfeld KE, Garnick DW, Luft HS,
Schaffarzick RW, Fowles J. Association of volume with outcome of
coronary artery bypass graft surgery. JAMA. 1987;257:785-789.
15. Hannan EL, Kilburn H, Bernard H, O’Donnell JF, Lukacik G, Shields BA. Coronary artery bypass surgery: the relationship between in-hospital mortality rate and surgical volume after controlling for clinical risk factors. Med Care. 1991;29:1094-1107.[Medline] [Order article via Infotrieve]
16. Luft HS, Bunker JP, Enthoven A. Should operations be regionalized? The empirical relation between surgical volume and mortality. N Engl J Med. 1979;301:1364-1369.[Abstract]
17. Krone RJ, Vetrovec GW, Noto TJ, Johnson LW, and the Registry Committee. PTCA operator variability: procedure complexity and outcome from the registry of the Society for Cardiac Angiography and Interventions. Circulation. 1993;88(suppl I):I-300. Abstract.
18. Altmann DB, Racz M, Battleman DS, Bergman G, Spokojny A, Hannan EL, Sanborn TA. Reduction in angioplasty complications after the introduction of coronary stents: results from a consecutive series of 2242 patients. Am Heart J. 1996;132:503-507.[Medline] [Order article via Infotrieve]
19. The EPIC investigators. Use of a monoclonal antibody
directed against the platelet glycoprotein IIb/IIIa
receptor in high-risk coronary angioplasty. N Engl
J Med. 1994;330:956-961.
20. Serruys PW, de Jaegere P, Kiemeneij F, Macaya C, Rutsch
W, Heyndrickx G, Emanuelsson H, Marco J, Legrand V, Materne P, Belgardi
J, Sigwart U, Colombo A, Goy JJ, Van Den Heuvel P, Delcan J, Morel MA,
for the Benestent Study Group. A comparison of balloon-expandable-stent
implantation with balloon angioplasty in patients with coronary
artery disease. N Engl J Med. 1994;331:489-495.
21. Fischman DL, Leon MB, Baim DS, Schatz RA, Savage
MP, Penn I, Detre K, Veltri L, Ricci D, Nobuyoshi M, Cleman M, Heuser
R, Almond D, Teirstein PS, Fish RD, Colombo A, Brinker J, Moses J,
Shaknovich A, Hirshfeld J, Bailey S, Ellis S, Rake R, Goldberg S, for
the Stent Restenosis Study Investigators. A randomized
comparison of coronary-stent placement and balloon angioplasty
in the treatment of coronary artery disease. N Engl
J Med. 1994;331:496-501.
22. Ellis SG, Omoigui N, Bittl JA, Lincoff M, Wolfe MW,
Howell G, Topol EJ. Analysis and comparison of
operator-specific outcomes in interventional
cardiology: from a multicenter database of 4860
quality-controlled procedures. Circulation. 1996;93:431-439.
23. Califf RM, Jollis JG, Peterson ED.
Operator-specific outcomes: a call to professional
responsibility. Circulation. 1996;93:403-406.
24. Angioplasty in New York State 1994. State of New York, New York State Department of Health; 1996.
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 H.-C. Lin, S. Xirasagar, C.-H. Chen, C.-C. Lin, and H.-C. Lee Association Between Physician Volume and Hospitalization Costs for Patients With Stroke in Taiwan: A Nationwide Population-Based Study Stroke, May 1, 2007; 38(5): 1565 - 1569. [Abstract] [Full Text] [PDF]
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 C. Spaulding, M.-C. Morice, B. Lancelin, S. El Haddad, E. Lepage, S. Bataille, J.-P. Tresca, X. Mouranche, S. Fosse, M. Monchi, et al. Is the volume-outcome relation still an issue in the era of PCI with systematic stenting? Results of the greater Paris area PCI registry Eur. Heart J., May 1, 2006; 27(9): 1054 - 1060. [Abstract] [Full Text] [PDF]
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 E. Solomon, J. Murray, W. W. Dodge, S. W. Redding, J. A. Valenza, C. M. Flaitz, J. S. Cole, and K. L. Kalkwarf Scope of practice comparison: a tool for curriculum decision making. J Dent Educ., March 1, 2006; 70(3): 231 - 245. [Abstract] [Full Text] [PDF]
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S. C. Smith Jr, T. E. Feldman, J. W. Hirshfeld Jr, A. K. Jacobs, M. J. Kern, S. B. King III, D. A. Morrison, W. W. O'Neill, H. V. Schaff, P. L. Whitlow, et al. ACC/AHA/SCAI 2005 Guideline Update for Percutaneous Coronary Intervention--Summary Article: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention) J. Am. Coll. Cardiol., January 3, 2006; 47(1): 216 - 235. [Full Text] [PDF]
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 S. C. Smith Jr, T. E. Feldman, J. W. Hirshfeld Jr, A. K. Jacobs, M. J. Kern, S. B. King III, D. A. Morrison, W. W. O'Neill, H. V. Schaff, P. L. Whitlow, et al. ACC/AHA/SCAI 2005 Guideline Update for Percutaneous Coronary Intervention--Summary Article: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention) Circulation, January 3, 2006; 113(1): 156 - 175. [Full Text] [PDF]
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T. P. Wharton Jr, E. C. Keeley, C. L. Grines, T. P. Wharton Jr, E. C. Keeley, and C. L. Grines The Case for Community Hospital Angioplasty Circulation, November 29, 2005; 112(22): 3509 - 3534. [Full Text] [PDF]
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 L. Durairaj, J. C. Torner, E. A. Chrischilles, M. S. Vaughan Sarrazin, J. Yankey, and G. E. Rosenthal Hospital Volume-Outcome Relationships Among Medical Admissions to ICUs Chest, September 1, 2005; 128(3): 1682 - 1689. [Abstract] [Full Text] [PDF]
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E. L. Hannan, C. Wu, G. Walford, S. B. King III, D. R. Holmes Jr, J. A. Ambrose, S. Sharma, S. Katz, L. T. Clark, and R. H. Jones Volume-Outcome Relationships for Percutaneous Coronary Interventions in the Stent Era Circulation, August 23, 2005; 112(8): 1171 - 1179. [Abstract] [Full Text] [PDF]
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M. Moscucci, D. Share, D. Smith, M. J. O'Donnell, A. Riba, R. McNamara, T. Lalonde, A. C. Defranco, K. Patel, E. Kline Rogers, et al. Relationship Between Operator Volume and Adverse Outcome in Contemporary Percutaneous Coronary Intervention Practice: An Analysis of a Quality-Controlled Multicenter Percutaneous Coronary Intervention Clinical Database J. Am. Coll. Cardiol., August 16, 2005; 46(4): 625 - 632. [Abstract] [Full Text] [PDF]
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 D. E. Wennberg, F. L. Lucas, A. E. Siewers, M. A. Kellett, and D. J. Malenka Outcomes of Percutaneous Coronary Interventions Performed at Centers Without and With Onsite Coronary Artery Bypass Graft Surgery JAMA, October 27, 2004; 292(16): 1961 - 1968. [Abstract] [Full Text] [PDF]
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W. D. Weaver Is Onsite Surgery Backup Necessary for Percutaneous Coronary Interventions? JAMA, October 27, 2004; 292(16): 2014 - 2016. [Full Text] [PDF]
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S. M. Kansagra, L. H. Curtis, and K. A. Schulman Regionalization of Percutaneous Transluminal Coronary Angioplasty and Implications for Patient Travel Distance JAMA, October 13, 2004; 292(14): 1717 - 1723. [Abstract] [Full Text] [PDF]
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A. J. Epstein, S. S. Rathore, K. G. M. Volpp, and H. M. Krumholz Hospital percutaneous coronary intervention volume and patient mortality, 1998 to 2000: Does the evidence support current procedure volume minimums? J. Am. Coll. Cardiol., May 19, 2004; 43(10): 1755 - 1762. [Abstract] [Full Text] [PDF]
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W. D. Weaver All Hospitals Are Not Equal for Treatment of Patients With Acute Myocardial Infarction Circulation, October 14, 2003; 108(15): 1768 - 1771. [Full Text] [PDF]
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 S. L. Hervey, H. R. Purves, U. Guller, A. P. Toth, T. P. Vail, and R. Pietrobon Provider Volume of Total Knee Arthroplasties and Patient Outcomes in the HCUP-Nationwide Inpatient Sample J. Bone Joint Surg. Am., September 1, 2003; 85(9): 1775 - 1783. [Abstract] [Full Text] [PDF]
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J. A. Spertus, M. J. Radford, N. R. Every, E. F. Ellerbeck, E. D. Peterson, and H. M. Krumholz Challenges and opportunities in quantifying the quality of care for acute myocardial infarction: Summary from the acute myocardial infarction working group of the American heart association/American college of cardiology first scientific forum on quality of care and outcomes research in cardiovascular disease and stroke J. Am. Coll. Cardiol., May 7, 2003; 41(9): 1653 - 1663. [Full Text] [PDF]
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J. A. Spertus, M. J. Radford, N. R. Every, E. F. Ellerbeck, E. D. Peterson, and H. M. Krumholz Challenges and Opportunities in Quantifying the Quality of Care for Acute Myocardial Infarction: Summary From the Acute Myocardial Infarction Working Group of the American Heart Association/American College of Cardiology First Scientific Forum on Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke Circulation, April 1, 2003; 107(12): 1681 - 1691. [Full Text] [PDF]
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 D. M. Shahian and S.-L. T. Normand The volume-outcome relationship: from Luft to Leapfrog Ann. Thorac. Surg., March 1, 2003; 75(3): 1048 - 1058. [Abstract] [Full Text] [PDF]
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 C. N. Klabunde, E. Jones, M. L. Brown, and W. W. Davis Colorectal Cancer Screening with Double-Contrast Barium Enema: A National Survey of Diagnostic Radiologists Am. J. Roentgenol., December 1, 2002; 179(6): 1419 - 1427. [Abstract] [Full Text] [PDF]
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 E. A. Halm, C. Lee, and M. R. Chassin Is Volume Related to Outcome in Health Care? A Systematic Review and Methodologic Critique of the Literature Ann Intern Med, September 17, 2002; 137(6): 511 - 520. [Abstract] [Full Text] [PDF]
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D. R. Thiemann Primary angioplasty for elderly patients with myocardial infarction: Theory, practice and possibilities J. Am. Coll. Cardiol., June 5, 2002; 39(11): 1729 - 1732. [Full Text] [PDF]
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 K. Stavem and O.M. Ronning Survival of unselected stroke patients in a stroke unit compared with conventional care QJM, March 1, 2002; 95(3): 143 - 152. [Abstract] [Full Text] [PDF]
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 S. Aronson and D. M. Thys Training and Certification in Perioperative Transesophageal Echocardiography: A Historical Perspective Anesth. Analg., December 1, 2001; 93(6): 1422 - 1427. [Full Text] [PDF]
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J. N. Katz, E. Losina, J. Barrett, C. B. Phillips, N. N. Mahomed, R. A. Lew, E. Guadagnoli, W. H. Harris, R. Poss, and J. A. Baron Association Between Hospital and Surgeon Procedure Volume and Outcomes of Total Hip Replacement in the United States Medicare Population J. Bone Joint Surg. Am., November 1, 2001; 83(11): 1622 - 1629. [Abstract] [Full Text] [PDF]
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M. A. Hlatky and R. A. Dudley Operator Volume and Clinical Outcomes of Primary Coronary Angioplasty for Patients With Acute Myocardial Infarction Circulation, October 30, 2001; 104(18): 2155 - 2157. [Full Text] [PDF]
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B. A. Vakili, R. Kaplan, and D. L. Brown Volume-Outcome Relation for Physicians and Hospitals Performing Angioplasty for Acute Myocardial Infarction in New York State Circulation, October 30, 2001; 104(18): 2171 - 2176. [Abstract] [Full Text] [PDF]
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M Gottwik, R Zahn, R Schiele, S Schneider, A.K Gitt, L Fraunberger, C Bossaller, H.G Glunz, E Altmann, W Rosahl, et al. Differences in treatment and outcome of patients with acute myocardial infarction admitted to hospitals with compared to without departments of cardiology. Results from the pooled data of the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA 1+2) Registries and the Myocardial Infarction Registry (MIR) Eur. Heart J., October 1, 2001; 22(19): 1794 - 1801. [Abstract] [PDF]
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J. V. Tu, P. C. Austin, and B. T. B. Chan Relationship Between Annual Volume of Patients Treated by Admitting Physician and Mortality After Acute Myocardial Infarction JAMA, June 27, 2001; 285(24): 3116 - 3122. [Abstract] [Full Text] [PDF]
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T. M. Bashore, E. R. Bates, P. B. Berger, D. A. Clark, J. T. Cusma, G. J. Dehmer, M. J. Kern, W. K. Laskey, M. P. O'Laughlin, S. Oesterle, et al. American College of Cardiology/Society for Cardiac Angiography and Interventions Clinical Expert Consensus Document on Cardiac Catheterization Laboratory Standards: A report of the American College of Cardiology Task Force on Clinical Expert Consensus Documents endorsed by the American Heart Association and the Diagnostic and Interventional Catheterization Committee of the Council on Clinical Cardiology of the AHA J. Am. Coll. Cardiol., June 15, 2001; 37(8): 2170 - 2214. [Full Text] [PDF]
|
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|
|
S. C. Smith Jr, J. T. Dove, A. K. Jacobs, J. Ward Kennedy, D. Kereiakes, M. J. Kern, R. E. Kuntz, J. J. Popma, H. V. Schaff, D. O. Williams, et al. ACC/AHA guidelines for percutaneous coronary intervention (revision of the 1993 PTCA guidelines): A report of the American College of Cardiology/ American Heart Association Task Force on practice guidelines (Committee to revise the 1993 guidelines for percutaneous transluminal coronary angioplasty) endorsed by the Society for Cardiac Angiography and Interventions J. Am. Coll. Cardiol., June 15, 2001; 37(8): 2239 - 2239. [Full Text] [PDF]
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P. D. McGrath, D. E. Wennberg, J. D. Dickens Jr, A. E. Siewers, F. L. Lucas, D. J. Malenka, M. A. Kellett Jr, and T. J. Ryan Jr Relation Between Operator and Hospital Volume and Outcomes Following Percutaneous Coronary Interventions in the Era of the Coronary Stent JAMA, December 27, 2000; 284(24): 3139 - 3144. [Abstract] [Full Text] [PDF]
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J. G. Jollis and P. S. Romano Volume-Outcome Relationship in Acute Myocardial Infarction: The Balloon and the Needle JAMA, December 27, 2000; 284(24): 3169 - 3171. [Full Text] [PDF]
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T. P. Wharton Jr., N. Sinclair McNamara, F. A. Fedele, M. I. Jacobs, A. R. Gladstone, and E. J. Funk Reply J. Am. Coll. Cardiol., July 1, 2000; 36(1): 301 - 303. [Full Text] [PDF]
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C. P. Cannon, C. M. Gibson, C. T. Lambrew, D. A. Shoultz, D. Levy, W. J. French, J. M. Gore, W. D. Weaver, W. J. Rogers, and A. J. Tiefenbrunn Relationship of Symptom-Onset-to-Balloon Time and Door-to-Balloon Time With Mortality in Patients Undergoing Angioplasty for Acute Myocardial Infarction JAMA, June 14, 2000; 283(22): 2941 - 2947. [Abstract] [Full Text] [PDF]
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V. Ho Evolution of the Volume-Outcome Relation for Hospitals Performing Coronary Angioplasty Circulation, April 18, 2000; 101(15): 1806 - 1811. [Abstract] [Full Text] [PDF]
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R. A. Dudley, K. L. Johansen, R. Brand, D. J. Rennie, and A. Milstein Selective Referral to High-Volume Hospitals: Estimating Potentially Avoidable Deaths JAMA, March 1, 2000; 283(9): 1159 - 1166. [Abstract] [Full Text] [PDF]
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Joint Working Group on Coronary Angioplasty of the and British Cardiovascular Intervention Society Coronary angioplasty: guidelines for good practice and training Heart, February 1, 2000; 83(2): 224 - 235. [Full Text]
|
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|
J. Lindsay Jr., E. E. Pinnow, and A. D. Pichard Frequency of major adverse cardiac events within one month of coronary angioplasty: a useful measure of operator performance J. Am. Coll. Cardiol., December 1, 1999; 34(7): 1916 - 1923. [Abstract] [Full Text] [PDF]
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J. W. Hirshfeld Jr., J. S. Banas Jr., M. Cowley, S. G. Ellis, D. P. Faxon, A. K. Jacobs, R. D. Magorien, S. Oesterle, M. Taubman, R. E. Vlietstra, et al. American College of Cardiology training statement on recommendations for the structure of an optimal adult interventional cardiology training program: A report of the American College of Cardiology Task Force on Clinical Expert Consensus documents J. Am. Coll. Cardiol., December 1, 1999; 34(7): 2141 - 2147. [Full Text] [PDF]
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P. D. McGrath, D. J. Malenka, D. E. Wennberg, S. J. Shubrooks Jr., W. A. Bradley, J. F. Robb, M. A. Kellett Jr., T. J. Ryan Jr., M. J. Hearne, B. Hettleman, et al. Changing outcomes in percutaneous coronary interventions: A study of 34,752 procedures in Northern New England, 1990 to 1997 J. Am. Coll. Cardiol., September 1, 1999; 34(3): 674 - 680. [Abstract] [Full Text] [PDF]
|
|
|
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G. T. O'Connor, D. J. Malenka, H. Quinton, J. F. Robb, M. A. Kellett Jr., S. Shubrooks, W. A. Bradley, M. J. Hearne, M. W. Watkins, D. E. Wennberg, et al. Multivariate prediction of in-hospital mortality after percutaneous coronary interventions in 1994-1996 J. Am. Coll. Cardiol., September 1, 1999; 34(3): 681 - 691. [Abstract] [Full Text] [PDF]
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|
|
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A. K. Berger, K. A. Schulman, B. J. Gersh, S. Pirzada, J. A. Breall, A. E. Johnson, and N. R. Every Primary Coronary Angioplasty vs Thrombolysis for the Management of Acute Myocardial Infarction in Elderly Patients JAMA, July 28, 1999; 282(4): 341 - 348. [Abstract] [Full Text] [PDF]
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N. R. Every, P. D. Frederick, M. Robinson, J. Sugarman, L. Bowlby, and H. V. Barron A comparison of the National Registry of Myocardial Infarction 2 with the Cooperative Cardiovascular Project J. Am. Coll. Cardiol., June 1, 1999; 33(7): 1886 - 1894. [Abstract] [Full Text] [PDF]
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V. Rill and D. L. Brown Practice of Coronary Angioplasty in California in 1995 : Comparison to 1989 and Impact of Coronary Stenting Circulation, June 1, 1999; 99 (21): e12 - e12. [Abstract] [Full Text] [PDF]
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 D. R. Thiemann, J. Coresh, W. J. Oetgen, and N. R. Powe The Association between Hospital Volume and Survival after Acute Myocardial Infarction in Elderly Patients N. Engl. J. Med., May 27, 1999; 340(21): 1640 - 1648. [Abstract] [Full Text] [PDF]
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S. Windecker, W. Maier-Rudolph, T. Bonzel, G. Heyndrickx, J.M. Lablanche, M.C. Morice, V. Muhlberger, K.L. Neuhaus, F. Piscione, M. van den Brand, et al. Interventional cardiology in Europe 1995 Eur. Heart J., April 1, 1999; 20(7): 484 - 495. [Abstract] [PDF]
|
|
|
|
|
|
S. G. Ellis, D. Miller, T. F. Keys, K. Brown, R. Ellert, G. Howell, A. M. Lincoff, and E. J. Topol Comparing physician-specific two-year patient outcomes after coronary angiography: Methodologic issues and results J. Am. Coll. Cardiol., April 1, 1999; 33(5): 1278 - 1285. [Abstract] [Full Text] [PDF]
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A. Kastrati, F.-J. Neumann, and A. Schomig Operator volume and outcome of patients undergoing coronary stent placement J. Am. Coll. Cardiol., October 1, 1998; 32(4): 970 - 976. [Abstract] [Full Text] [PDF]
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 In PTCA, Practice Makes Perfect Journal Watch Cardiology, June 20, 1997; 1997(620): 3 - 3. [Full Text]
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