Hierarchy of evidence referring to the central nervous system in a high-impact radiation oncology journal
a 10-year assessment. Descriptive critical appraisal study
Keywords:
Radiotherapy, Central nervous system neoplasms, Epidemiologic methods, Research design, Evidence-based medicineAbstract
CONTEXT AND OBJECTIVE: To the best of our knowledge, there has been no systematic assessment of the classification of scientific production within the scope of radiation oncology relating to central nervous system tumors. The aim of this study was to systematically assess the status of evidence relating to the central nervous system and to evaluate the geographic origins and major content of these published data. DESIGN AND SETTING: Descriptive critical appraisal study conducted at a private hospital in São Paulo, Brazil. METHODS: We evaluated all of the central nervous system studies published in the journal Radiotherapy & Oncology between 2003 and 2012. The studies identified were classified according to their method-ological design and level of evidence. Information regarding the geographical location of the study, the institutions and authors involved in the publication, main condition or disease investigated and time of publication was also obtained. RESULTS: We identified 3,004 studies published over the 10-year period. Of these, 125 (4.2%) were con-sidered eligible, and 66% of them were case series. Systematic reviews and randomized clinical trials accounted for approximately 10% of all the published papers. We observed an increase in high-quality evidence and a decrease in low-quality published papers over this period (P = 0.036). The inter-rater reliability demonstrated significant agreement between observers in terms of the level of evidence. CONCLUSIONS: Increases in high-level evidence and in the total number of central nervous system pa-pers were clearly demonstrated, although the overall number of such studies remained relatively small.
Downloads
References
Guyatt G, Rennie D, Meade M, Cook D. Users’ guide to the medical literature: a manual for evidence-based clinical practice. 2nd ed. New York: McGraw-Hill; 2008.
Hoppe DJ, Bhandari M. Evidence-based orthopaedics: a brief history. Indian J Orthop. 2008;42(2):104-10.
Watts G. Let’s pension off the “major breakthrough”. BMJ. 2007;334 Suppl 1:s4.
Overgaard J, Bentzen SM. Evidence-based radiation oncology. Radiother Oncol. 1998;46(1):1-3.
Overgaard J. Advancing radiation oncology through scientific publication--100 volumes of Radiotherapy and Oncology. Radiother Oncol. 2011;100(1):1-6.
Torloni MR, Riera R. Design and level of evidence of studies published in two Brazilian medical journals recently indexed in the ISI Web of Science database. Sao Paulo Med J. 2010;128(4):202-5.
Bhandari M, Richards RR, Sprague S, Schemitsch EH. The quality of reporting of randomized trials in the Journal of Bone and Joint Surgery from 1988 through 2000. J Bone Joint Surg Am. 2002;84-A(3):388-96.
Bhandari M, Swiontkowski MF, Einhorn TA, et al. Interobserver agreement in the application of levels of evidence to scientific papers in the American volume of the Journal of Bone and Joint Surgery. J Bone Joint Surg Am. 2004;86-A(8):1717-20.
Centre for Evidence-Based Medicine. OCEBM Levels of Evidence. Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence. Available from: http://www.cebm.net/wp-content/ uploads/2014/06/CEBM-Levels-of-Evidence-2.1.pdf. Accessed in 2014 (Nov 18).
Bagshaw SM, Bellomo R. The need to reform our assessment of evidence from clinical trials: a commentary. Philos Ethics Humanit Med. 2008;3:23.
Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977;33(1):159-74.
Jemal A, Siegel R, Ward E, et al. Cancer statistics, 2008. CA Cancer J Clin. 2008;58(2):71-96.
Delaney G, Jacob S, Featherstone C, Barton M. The role of radiotherapy in cancer treatment: estimating optimal utilization from a review of evidence-based clinical guidelines. Cancer. 2005;104(6):1129-37.
Delaney G, Jacob S, Barton M. Estimating the optimal radiotherapy utilization for carcinoma of the central nervous system, thyroid carcinoma, and carcinoma of unknown primary origin from evidence-based clinical guidelines. Cancer. 2006;106(2):453-65.
Usmani N, Foroudi F, Du J, et al. An evidence-based estimate of the appropriate rate of utilization of radiotherapy for cancer of the cervix. Int J Radiat Oncol Biol Phys. 2005;63(3):812-27.
Featherstone C, Delaney G, Jacob S, Barton M. Estimating the optimal utilization rates of radiotherapy for hematologic malignancies from a review of the evidence: part II - leukemia and myeloma. Cancer. 2005;103(2):393-401.
Featherstone C, Delaney G, Jacob S, Barton M. Estimating the optimal utilization rates of radiotherapy for hematologic malignancies from a review of the evidence: part I - lymphoma. Cancer. 2005;103(2):383-92.
Delaney G, Barton M, Jacob S. Estimation of an optimal radiotherapy utilization rate for gastrointestinal carcinoma: a review of the evidence. Cancer. 2004;101(4):657-70.
Yarascavitch BA, Chuback JE, Almenawer SA, Reddy K, Bhandari M. Levels of evidence in the neurosurgical literature: more tribulations than trials. Neurosurgery. 2012;71(6):1131-7; discussion 1137-8.
Hanzlik S, Mahabir RC, Baynosa RC, Khiabani KT. Levels of evidence in research published in The Journal of Bone and Joint Surgery (American Volume) over the last thirty years. J Bone Joint Surg Am. 2009;91(2):425-8.
Wright JG, Swiontkowski MF. Introducing a New Journal Section: Evidence-Based Orthopaedics. J Bone Joint Surg Am. 2000;82(6):759. Available from: http://jbjs.org/content/82/6/759. Accessed in 2014 (Nov 18).
Poolman RW, Struijs PA, Krips R, et al. Does a “Level I Evidence” rating imply high quality of reporting in orthopaedic randomised controlled trials? BMC Med Res Methodol. 2006;6:44.
Wasserman JM, Wynn R, Bash TS, Rosenfeld RM. Levels of evidence in otolaryngology journals. Otolaryngol Head Neck Surg. 2006;134(5):717-23.
Thoma A, Ignacy TA, Li YK, Coroneos CJ. Reporting the level of evidence in the Canadian Journal of Plastic Surgery: Why is it important? Can J Plast Surg. 2012;20(1):12-6.
Amiri AR, Kanesalingam K, Cro S, Casey AT. Level of evidence of clinical spinal research and its correlation with journal impact factor. Spine J. 2013;13(9):1148-53.
Tieman J, Sladek R, Currow D. Changes in the quantity and level of evidence of palliative and hospice care literature: the last century. J Clin Oncol. 2008;26(35):5679-83.
Morgan PB, Sopka DM, Kathpal M, et al. First author research productivity of United States radiation oncology residents: 2002-2007. Int J Radiat Oncol Biol Phys. 2009;74(5):1567-72.
Turpen RM, Fesperman SF, Sultan S, et al. Levels of evidence ratings in the urological literature: an assessment of interobserver agreement. BJU Int. 2010;105(5):602-6.
