Journal of Clinical Oncology, Vol 19, Issue 6
(March), 2001: 1728-1733
© 2001 American Society for Clinical Oncology
Prospective Evaluation of Cancer Clinical Trial Accrual Patterns: Identifying Potential Barriers to Enrollment
By Primo N. Lara, Jr,
Roger Higdon,
Nelson Lim,
Karen Kwan,
Michael Tanaka,
Derick H.M. Lau,
Ted Wun,
Jeanna Welborn,
Frederick J. Meyers,
Scott Christensen,
Robert O’Donnell,
Carol Richman,
Sidney A. Scudder,
Joseph Tuscano,
David R. Gandara,
Kit S. Lam
From the Division of Hematology-Oncology, Department of Internal Medicine, and Department of Epidemiology/Biostatistics, University of California Davis Cancer Center, Sacramento, CA
Address reprint requests to Primo N. Lara, Jr, MD, University of California Davis Cancer Center, 4501 X St, Sacramento, CA 95817; email: primo.lara{at}ucdmc.ucdavis.edu
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ABSTRACT
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PURPOSE: Well-conducted cancer clinical trials are essential for improving patient outcomes. Unfortunately, only 3% of new cancer patients participate in clinical trials. Barriers to patient accrual in cancer clinical trials must be identified and overcome to increase patient participation.
MATERIALS AND METHODS: We prospectively tracked factors that potentially affected patient accrual into cancer clinical trials at the University of California Davis Cancer Center. Oncologists seeing new outpatients were asked to complete questionnaires regarding patient characteristics and the physician’s decision-making on patient eligibility, protocol availability, and patient opinions on participation. Statistical analysis was performed to correlate these parameters with subsequent protocol accrual.
RESULTS: There were 276 assessable patients. At the initial visits, physicians did not consider clinical trials in 38% (105/276) of patients principally because of a perception of protocol unavailability and poor performance status. Physicians considered 62% (171/276) of patients for participation in clinical trials. Of these, only 53% (91/171) had an appropriate protocol available for site and stage of disease. Seventy-six of 90 patients (84%) with available protocols met eligibility criteria for a particular study. Only 39 of 76 patients (51%) agreed to participate in cancer clinical trials, for an overall accrual rate of 14% (39/276). The remainder (37/76, 49%) declined trial participation despite meeting eligibility criteria. The most common reasons were a desire for other treatment (34%), distance from the cancer center (13%), patient refusal to disclose reason (11%), and insurance denial (8%). Patients with private insurance were less likely to enroll in clinical trials compared to those with government-funded insurance (OR, 0.34; P = .03; 95% CI, 0.13 to 0.9).
CONCLUSION: Barriers to cancer clinical trial accrual can be prospectively identified and addressed in the development and conduct of future studies, which may potentially lead to more robust clinical trials enrollment. Investigation of patient perceptions regarding the clinical trials process and the role of third party–payers is warranted.
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INTRODUCTION
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CANCER IS A leading cause of death in the United States, second only to heart disease, and it accounts for more than one-half million deaths annually.1 The efficacy of new cancer treatments can only be reasonably confirmed through carefully designed prospective clinical trials. A key requirement in the conduct of these trials is the enrollment of sufficient numbers of participants to establish adequate statistical power and generalizability to the intended population. In addition, clinical trials offer cancer patients access to innovative therapeutic approaches and have the potential of improving clinical outcomes. In fact, a recent meta-analysis has shown that centralized referral or entry into clinical trials was frequently associated with a higher survival rate.2
Unfortunately, only 2% to 4% of all adult patients with newly diagnosed cancer participate in clinical trials annually. For example, only 3% of the 160,000 newly diagnosed breast cancer patients and less than 2% of the 160,000 patients with colorectal cancer participated in trials in the United States in 1990.3 This is despite survey results from the 1980s in which the majority of cancer patients and the general public who were sampled indicated that patients should be asked to participate in clinical trials, and that they themselves would participate if asked.4 In addition, representation of minorities and the elderly in clinical trials has been low.5,6,7 Low accrual rates clearly have a negative impact, often prolonging the duration of the trials, delaying the analysis of important results, or leading to early closure of important studies. Understanding the reasons behind low patient accrual rates is essential in order to increase participation in clinical trials. Unfortunately, little data exist that address this issue.
In an effort to address the scarcity of data on clinical trial participation, we conducted a prospective study of patient accrual patterns in cancer clinical trials offered at the University of California Davis (UCD) Cancer Center. The objectives were to determine the overall accrual rate of new patients who were seen as outpatients into available clinical trials, to evaluate the factors that may affect protocol eligibility, to study the characteristics of patients who failed to enroll in any clinical study but were otherwise eligible, to evaluate the impact of these observations on the design and development of future studies, and to increase awareness for greater trial participation. The data obtained may help fill in knowledge gaps in patient accrual issues and identify modifiable barriers to patient enrollment, with an aim toward ultimately improving accession rates to trials.
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MATERIALS AND METHODS
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We prospectively tracked factors that affect patient accrual in cancer clinical trials available at the UCD Cancer Center during three time periods: January 15 to June 15, 1997; September 1 to December 1, 1998; and January 1 to April 30, 2000. There were 12 medical oncologists and six fellows seeing patients at the UCD Cancer Center during these time periods. Sampling was performed over three time periods to adjust for the variability in protocol availability at different points in time. During these periods, physicians were alerted to the availability of protocols by dissemination of a paper copy of the quarterly protocol list that organized the available trials by tumor type and by study phase. This same list is available electronically on a password-protected intranet server that can be accessed by Cancer Center physicians. A similar list, though updated less frequently, is also posted on the UCD Cancer Center web site. Determination of the real-time status of protocols requires a phone call to the clinical trials office, which is located on-site. Patients were not prescreened for trial eligibility before seeing any of the UCD Cancer Center physicians. Medical oncologists were asked to complete questionnaires that inquired about patient characteristics and clinical trial eligibility. The single-sheet questionnaires were appended to the progress notes of most new patients seen at the UCD Cancer Center during the above time periods. The standardized questionnaire first inquired about whether the physician considered enrolling a particular patient in a clinical trial (ie, physician triage). If not, the physician was asked to give the reason ( Table 1). The second question was about the availability of an appropriate protocol. (There were over 100 cancer clinical trials available for various tumor types during each of the time periods evaluated.) The third question asked whether the patient met eligibility requirements as defined in a particular trial. Finally, the physician was asked whether the patient agreed to participate in a clinical trial. If not, the patient’s reason for not enrolling was requested and documented.
Available data was entered into a Microsoft Excel database (Microsoft Corp, Redmond, WA). We generated descriptive statistics of patient characteristics and performed univariate analysis to evaluate the associations of these characteristics with protocol accrual. Associations were assessed using the  2 test. Odds ratios (OR) and 95% confidence intervals (CI) were generated. All statistical analyses were performed using SAS (Cary, NC). Statistical significance was set at P < .05.
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RESULTS
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A total of 350 forms were completed and submitted for evaluation. There was no cancer diagnosis for 70 patients and incomplete data in four patients. These patients were excluded, so 276 patients were found to be eligible for analysis. Patient characteristics and factors that affect cancer clinical trial accrual were tabulated and analyzed ( Table 2). Females outnumbered males (57% v 43%). Median age was 62 years within a range of 17 to 88. The majority of patients were Caucasian (76%), followed by Hispanic (8%), Asian (4%), Black (3%), and others. Most patients had private insurance (47%), which included HMOs, PPOs, and similar plans, whereas the rest had Medicare (33%), MediCal (9%), County (5%), self paid (4%), and others. Most patients were referred by surgeons (35%) and primary care physicians (31%).
Physician Triage
Physicians did not consider clinical trials in 38% (105/276) of patients. The primary reasons were: No available protocol in 22 patients (21%), poor performance status in 20 (19%), patient not expected to return in 12 (11%), previous therapy in 11 (10%), no evidence of disease in 9 (9%), no pathologic diagnosis in 8 (8%), synchronous primary tumors in 5 (5%), unknown primary cancer in 5 (5%), and other reasons in 13 (12%). None of the patient characteristics were found to be statistically significant (univariate analysis) in influencing physician triage decision-making ( Table 3).
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Table 3. Patient Characteristics and Odds of Physician Considering a Patient for Trial Participation: Univariate Analysis
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Protocol Availability
Physicians considered 62% (171/276) of patients for clinical trials; however, only 53% (91/171) of patients had protocols appropriate for site and stage available at the time of the survey. Conversely, 47% of patients (80/171) had no available protocols. Univariate analysis did not reveal any statistically significant patient characteristic (data not shown) that influenced protocol availability.
Patient Eligibility
Seventy-six of 90 patients (84%) with available protocols met eligibility criteria for particular studies. One patient had incomplete data to assess eligibility. Fourteen of 91 patients (15%) were found to be ineligible. Univariate analysis did not reveal any statistically significant patient characteristic associated with trial participation (data not shown).
Patient Decision
Only 39 of 76 patients (51%) agreed to participate in a cancer clinical trial, for an overall accrual rate of 14% (39/276). The rest of the 76 patients who met eligibility criteria (37; 49%) declined trial participation. The reasons for refusal are listed in Table 4. The most common reasons were a desire for other treatment, distance from the cancer center, insurance denial, and patient refusal to disclose reason. Univariate analysis ( Table 5) revealed that patients with private insurance are less likely to enroll in clinical trials compared with those who have government-funded insurance (Medicare or MediCal) with an OR of 0.34; 95% CI, 0.13 to 0.9; and P = 0.03.
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DISCUSSION
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New anticancer therapies based on our increased understanding of tumor biology are being developed at an increasing pace. Cancer clinical trials are critical in evaluating the safety and efficacy of these novel treatments. Unfortunately, only 3% of newly diagnosed adult cancer patients participate in clinical trials annually. This is in contrast to pediatric oncology, in which the standard of care is the enrollment of patients into peer reviewed, cooperative group clinical trials, which results in an accession rate that exceeds 60%.8,9 Barriers to patient enrollment in adult cancer clinical trials must be identified and overcome to increase trial participation. We prospectively evaluated factors that affect patient accrual in cancer clinical trials offered at the UCD Cancer Center in three time periods from 1997 to 2000. The Hematology-Oncology Division at UCD sees  1,200 new outpatients annually. Our initial sample size (N = 350), therefore, accounts for approximately one-third of new patients seen on an annualized ratio. We determined an overall accrual rate of 14% from 276 eligible patients, a rate well above the national average; however, several barriers to patient enrollment were identified, including an ethnically homogenous population (80% Caucasian), geographic and data management problems, and third party–payer influence.
Factors that contribute to low accrual rates are empirically determinable. We hypothesize that gathering such data will provide the basis for systematic assessment of the influence of the change in factors that influence study enrollment, thereby suggesting ways to increase clinical trial accrual. Barriers can be summarized into four broad groups: (i) physician barriers, (ii) protocol or eligibility barriers, (iii) patient barriers, and (iv) funding barriers. These are all potentially modifiable in that efforts can be made by study investigators to reduce the influence of these barriers on accrual.
Surveys done in North America suggest that 50% to 80% of eligible cancer patients are not enrolled in the clinical trials appropriate for their types and stages of disease because of their physicians’ decisions not to offer any trial.1 In our study, physicians excluded up to one-third of patients from clinical trial consideration even before reviewing protocol availability and eligibility criteria. This is a form of bias predicated on the treating physician’s ideal conception of an eligible patient. The most common reason that physicians cited for excluding a patient outright was their perception of "no available protocol" appropriate for that particular patient’s tumor site and stage. This perception is clearly not the actual case for many patients because most cancer centers (including ours) offer a variety of trials, including phase I trials that allow any type of advanced malignancy. Physicians are, therefore, encouraged to regularly check the protocol lists before assuming protocol unavailability. Clinical trials administrators, on the other hand, should redouble efforts to inform physicians of the status of ongoing trials and the availability of new ones.
Poor performance status was the second most common reason for physician nonconsideration. Poor status notwithstanding, some trials may potentially allow patients with borderline performance status; therefore, physicians must be encouraged to consider all patients for clinical trial enrollment and to exclude individuals only on the basis of protocol unavailability or ineligibility. The availability of certain clinical trials for defined patient subsets that were previously perceived by physicians to be ineligible (eg, patients with renal or hepatic dysfunction, or the elderly) will allow broader patient access to trials. Of even greater importance is the referral of cancer patients for possible trial enrollment before performance status declines. An example of the utility of this "window of opportunity" for protocol accrual can be found in the American Society of Clinical Oncology guidelines for the management of advanced non–small-cell lung cancer.10 According to these guidelines, chemotherapy should be started soon after the diagnosis of unresectable non–small-cell lung cancer is made, because delaying treatment until performance status worsens or weight loss develops may negate the survival benefits of therapy.
The barrier of protocol unavailability can best be overcome by the activation of a wide variety of trials, particularly early phase studies that investigate novel therapeutic approaches in accord with institutional commitments to the clinical research process. Ongoing federally funded efforts to increase the number and quality of cancer clinical trials should help in this regard. Strict protocol eligibility criteria must also be relaxed to increase access to trials by patients in reasonable physical condition. This will also have the effect of making the results more applicable to the general patient population. An example of this relaxation is to admit patients with symptomatically-controlled brain metastases in most planned studies. A recent comparison of eligibility criteria of National Surgical Adjuvant Breast and Bowel Project (NSABP) trials with Pediatric Oncology Group (POG) trials demonstrated that NSABP trials were significantly more restrictive than POG trials.11 The investigators concluded that eligibility criteria could be simplified without jeopardizing quality. Furthermore, the following recommendations were made: (1) abandonment of the inclusion versus exclusion criteria distinction, (2) make explicit the justification of eligibility criteria, (3) assess the need for each criterion when new trials are planned, (4) minimize restrictive criteria in phase III trials, and (5) perform research that assesses the impact of eligibility criteria on generalizability. Recently, the adult oncology cooperative groups have begun simplifying protocol development, including eligibility criteria, based on "good clinical practice" guidelines that have been recommended by federal and regulatory agencies.12
Racial and ethnic minority groups continue to be underrepresented in clinical trials. In our own study, the vast majority of patients enrolled in clinical studies were of Caucasian descent, reflecting the ethnic distribution of Northern California. Nevertheless, efforts must continue to be made to encourage minority participation. Among the reasons cited in the literature for minority underrepresentation are the lack opportunities to participate, distrust for the Caucasian-dominated system, and lack of information about trial availability.13 These social barriers can be overcome with community education programs, perhaps led by the university-based cancer centers and co-sponsored by private and government institutions. One innovative approach includes using houses of worship as bases for cancer education and information dissemination. Another would be to continue current efforts to recruit minority physicians into clinical trials programs to help obviate some underlying distrust of the medical system.
Patients choose not to participate in trials for many reasons. In our study, half the patients who were otherwise eligible for trial enrollment refused to participate. The reasons cited by patients for their nonparticipation dwell mainly on geography, a desire for noninvestigational therapies, fear of randomization, and third party–payer difficulties. Geographical barriers are best overcome by promoting community clinical trials programs that provide access to trials closer to patients’ homes than are some university cancer centers. A desire for noninvestigational therapies or fear of randomization may be addressed through pertinent education and an "informative" informed consent process in which the treating physician, nurse, and clinical research associate discuss specific aspects of a particular trial in detail with the patient. This clearly would increase the length of the initial visit and could potentially disrupt clinic schedules, increasing the "hassle factor" in trial enrollment. Consequently, unless adequate reimbursement is forthcoming for a lengthy informed consent discussion, this barrier may be the most difficult one to hurdle.
Fear of insurance denial is a reason for nonparticipation, and it appears to be a growing concern to patients who are considering clinical trial participation. Despite the fact that only 8% of the patients failed to participate because of third party–payer denial of coverage, analysis of the data suggests that patients with nongovernment insurance were statistically less likely to participate than those with government insurance. The hypothesis generated is that patients with private insurance have a perception that they may not be adequately covered by their third party payers if they participate in a clinical trial. Another prospective study of patients’ perceptions of clinical trials funding may need to be done to investigate this issue. However, this issue may become moot if legislative relief occurs under which third party payers are asked to reimburse the routine costs related to clinical trials in all fifty states.
In conclusion, our study demonstrates that potentially modifiable barriers to cancer clinical trial accrual can be identified, and data on these barriers can be used in the development, refinement, and conduct of current and future protocols. Further studies to investigate patient perceptions of the clinical trials process, as well as of the role of third party payers, are warranted.
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ACKNOWLEDGMENTS
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P.N.L. is supported in part by American Cancer Society Clinical Research Training Grant no. 0019701CCE.
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NOTES
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Presented in part at the Thirty-Fifth Annual Meeting of the American Society of Clinical Oncology, Atlanta, GA, May 15-18, 1999.
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REFERENCES
|
|---|
1.
Greenlee RT, Murray T, Bolden S, et al: Cancer Statistics. CA Cancer J Clin 50: 7-33, 2000[Abstract]
2.
Stiller C: Centralised treatment, entry to trials, and survival. Br J Cancer 70: 352-362, 1994[Medline]
3.
Joseph R: Viewpoints and concerns of a clinical trial participant. Cancer 74: 2692-2693, 1994[Medline]
4.
Ellis PM, Butow PN, Simes RJ, et al: Barriers to participation in randomized clinical trials for early breast cancer among Australian cancer specialists. Aust N Z J Surg 69: 486-491, 1999[Medline]
5.
Trimble EL, Carter CL, Cain D, et al: Representation of older patients in cancer treatment trials. Cancer 74: 2208-2214, 1994 (suppl 7)[Medline]
6.
Kaluzny A, Brawley O, Garson-Angert D, et al: Assuring access to state-of-the-art care for U.S. minority populations: The first 2 years of Minority-Based Community Clinical Oncology Program. J Natl Cancer Inst 85: 1945-1950, 1993[Abstract/Free Full Text]
7.
Tejeda HA, Green SB, Trimble EL, et al: Representation of African-Americans, Hispanics, and whites in National Cancer Institute treatment trials. J Natl Cancer Inst 88: 812-816, 1996
8.
National Children’s Cancer Foundation: Childhood cancer facts. http://www.nccf.org/
9.
Kolata G, Eichewald K: In pediatrics, a lesson in making use of experimental procedures. New York Times. October 3, 1999
10.
American Society of Clinical Oncology: Clinical practice guidelines for the treatment of unresectable non-small-cell lung cancer. J Clin Oncol 15:2996-3018, 1997
11.
Fuks A, Weijer C, Freedman B, et al: A study in contrasts: Eligibility criteria in a twenty-year sample of NSABP and POG clinical trials. J Clin Epidemiol 51: 69-79, 1998[Medline]
12.
Good clinical practice: Consolidated guideline. Federal Register 62:25691-25709, 1997
13.
Albrecht TL, Blanchard C, Ruckdeschel JC, et al: Strategic physician communication and oncology clinical trials. J Clin Oncol 17: 3324-3332, 1999.[Abstract/Free Full Text]
Submitted August 2, 2000;
accepted November 20, 2000.
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|
|
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|
|
|
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|
|
|
|
|
|
|
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23(3):
654 - 655.
[Full Text]
[PDF]
|
|
|
|
|
|
|
S.J. Wei, J.M. Metz, C. Coyle, M. Hampshire, H.A. Jones, S. Markowitz, and A.K. Rustgi
Recruitment of Patients Into an Internet-Based Clinical Trials Database: The Experience of OncoLink and the National Colorectal Cancer Research Alliance
J. Clin. Oncol.,
December 1, 2004;
22(23):
4730 - 4736.
[Abstract]
[Full Text]
[PDF]
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L. Talarico, G. Chen, and R. Pazdur
Enrollment of Elderly Patients in Clinical Trials for Cancer Drug Registration: A 7-Year Experience by the US Food and Drug Administration
J. Clin. Oncol.,
November 15, 2004;
22(22):
4626 - 4631.
[Abstract]
[Full Text]
[PDF]
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M. S. Simon, W. Du, L. Flaherty, P. A. Philip, P. Lorusso, C. Miree, D. Smith, and D. R Brown
Factors Associated With Breast Cancer Clinical Trials Participation and Enrollment at a Large Academic Medical Center
J. Clin. Oncol.,
June 1, 2004;
22(11):
2046 - 2052.
[Abstract]
[Full Text]
[PDF]
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M. M. Kemeny, B. L. Peterson, A. B. Kornblith, H. B. Muss, J. Wheeler, E. Levine, N. Bartlett, G. Fleming, and H. J. Cohen
Barriers to Clinical Trial Participation by Older Women With Breast Cancer
J. Clin. Oncol.,
June 15, 2003;
21(12):
2268 - 2275.
[Abstract]
[Full Text]
[PDF]
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D. P. Goldman, S. H. Berry, M. S. McCabe, M. L. Kilgore, A. L. Potosky, M. L. Schoenbaum, M. Schonlau, J. C. Weeks, R. Kaplan, and J. J. Escarce
Incremental Treatment Costs in National Cancer Institute-Sponsored Clinical Trials
JAMA,
June 11, 2003;
289(22):
2970 - 2977.
[Abstract]
[Full Text]
[PDF]
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K. W.L. Yee, J. L. Pater, L. Pho, B. Zee, and L. L. Siu
Enrollment of Older Patients in Cancer Treatment Trials in Canada: Why is Age a Barrier?
J. Clin. Oncol.,
April 15, 2003;
21(8):
1618 - 1623.
[Abstract]
[Full Text]
[PDF]
|
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B. R. Cassileth
Clinical Trials: Time for Action
J. Clin. Oncol.,
March 1, 2003;
21(5):
765 - 766.
[Full Text]
[PDF]
|
|
|
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R. L. Comis, J. D. Miller, C. R. Aldige, L. Krebs, and E. Stoval
Public Attitudes Toward Participation in Cancer Clinical Trials
J. Clin. Oncol.,
March 1, 2003;
21(5):
830 - 835.
[Abstract]
[Full Text]
[PDF]
|
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G. I. Cohen
Clinical Research by Community Oncologists
CA Cancer J Clin,
March 1, 2003;
53(2):
73 - 81.
[Abstract]
[Full Text]
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TOP
ABSTRACT
INTRODUCTION
