Overdiagnosis
In epidemiology and mass screening, overdiagnosis, or over diagnosis, is the diagnosis of non-harmful disease by diagnostic tests.[1][2] Overdiagnosis inflates the importance of the screening problem. Overdiagnosis is also an issue in trauma and emergency medicine.
Overdiagnosis has been shown to occur in the screening of breast cancer (rate may 10%[3] or higher[4]), lung cancer (rate may be 2%)[5], prostate cancer (rate may be 15% in whites and 37% in blacks)[6][7], and renal cancer[8].
Overdiagnosis can be prevented by studying the screening program with a randomized controlled trial in which one arm of the trial the subjects are randomly assigned to the screening program and in the other arm of the trial, subjects are assigned to the control group. Examination of the rate of diagnosis over time detects overdiagnosis: [5]
- "If overdiagnosis has not occurred, the cumulative number of cases in each arm will equalize with time after screening stops (i.e., catch-up) as the counterparts of the earlier screen-detected cancers are detected symptomatically in the control arm."
- "If overdiagnosis has occurred, the number of cases in both arms will never equalize because the excess cases in the intervention arm will have no counterparts in the control arm."
Trauma specialists, on the trauma.org mailing list, often argue about diagnoses not supported by clinical observations but by imaging studies, and the too-early use of exploratory diagnostic surgery rather than watchful waiting and serial observations. The arguments are complex; many distinguished surgeons also criticize avoidance of exploration, or more invasive imaging such contrast angiography, over less invasive, but not necessarily benign in radiation exposure, techniques such as computerized X-ray tomography.
An informal but memorable term is VOMIT, or Victim Of Modern Imaging Technology. In emergency medicine, the use of imaging to rule out clinically unlikely syndromes, sometimes as part of defensive medicine, may lead to extensive, expensive, and even hazardous interventions over an equivocal finding on imaging. Imaging has an enormous value, but is sometimes is not used appropriately. Examples include ankle X-rays without first establishing the Ottawa ankle rules to determine that a fracture probably exists, [9] or the use of d-dimer levels for ruling out deep venous thrombosis without going immediately to more expensive doppler ultrasonography.
References
- ↑ Black WC, Welch HG (April 1993). "Advances in diagnostic imaging and overestimations of disease prevalence and the benefits of therapy". N. Engl. J. Med. 328 (17): 1237–43. PMID 8464435. [e]
- ↑ Esserman L, Shieh Y, Thompson I (2009). "Rethinking screening for breast cancer and prostate cancer.". JAMA 302 (15): 1685-92. DOI:10.1001/jama.2009.1498. PMID 19843904. Research Blogging.
- ↑ Zackrisson S, Andersson I, Janzon L, Manjer J, Garne JP (March 2006). "Rate of over-diagnosis of breast cancer 15 years after end of Malmö mammographic screening trial: follow-up study". BMJ 332 (7543): 689–92. DOI:10.1136/bmj.38764.572569.7C. PMID 16517548. PMC 1410836. Research Blogging.
- ↑ Jørgensen KJ, Gøtzsche PC (2009). "Overdiagnosis in publicly organised mammography screening programmes: systematic review of incidence trends.". BMJ 339: b2587. DOI:10.1136/bmj.b2587. PMID 19589821. Research Blogging.
- ↑ 5.0 5.1 Marcus PM, Bergstralh EJ, Zweig MH, Harris A, Offord KP, Fontana RS (June 2006). "Extended lung cancer incidence follow-up in the Mayo Lung Project and overdiagnosis". J. Natl. Cancer Inst. 98 (11): 748–56. DOI:10.1093/jnci/djj207. PMID 16757699. Research Blogging.
- ↑ Etzioni R, Penson DF, Legler JM, et al (July 2002). "Overdiagnosis due to prostate-specific antigen screening: lessons from U.S. prostate cancer incidence trends". J. Natl. Cancer Inst. 94 (13): 981–90. PMID 12096083. [e]
- ↑ Welch HG and Albertsen PC. Prostate cancer diagnosis and treatment after the introduction of prostate-specific antigen screening: 1986–2005. J Natl Cancer Inst 2009 Aug 31; [e-pub ahead of print]. DOI:10.1093/jnci/djp278
- ↑ Lane BR, Abouassaly R, Gao T, Weight CJ, Hernandez AV, Larson BT et al. (2010). "Active treatment of localized renal tumors may not impact overall survival in patients aged 75 years or older.". Cancer 116 (13): 3119-26. DOI:10.1002/cncr.25184. PMID 20564627. Research Blogging.
- ↑ Bachmann LM et al. (22 February 2003), "Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review", BMJ 326: 417, DOI:10.1136/bmj.326.7386.417