Clinical prediction rule: Difference between revisions
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!'''Risk Score''' | |||
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! style="text-align:center"|'''Purpose''' | |||
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| [[HAS-BLED score|HAS-BLED]] | | [[HAS-BLED score|HAS-BLED]] |
Revision as of 20:16, 16 May 2012
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
A clinical prediction rule is type of medical research study in which researchers try to identify the best combination of medical sign, symptoms, and other findings in predicting the probability of a specific disease or outcome.[1]
Physicians have difficulty in estimated risks of diseases; frequently erring towards overestimation[2], perhaps due to cognitive biases such as base rate fallacy in which the risk of an adverse outcome is exaggerated.
Methods
In a prediction rule study, investigators identify a consecutive group of patients who are suspected of a having a specific disease or outcome. The investigators then compare the value of clinical findings available to the physician versus the results of more intensive testing or the results of delayed clinical follow up.
Effect on health outcomes
Few prediction rules have had the consequences of their usage by physicians quantified.[3]
When studied, the impact of providing the information alone (for example, providing the calculated probability of disease) has been negative.[4][5]
However, when the prediction rule is implemented as part of a critical pathway, so that a hospital or clinic has procedures and policies established for how to manage patients identified as high or low risk of disease, the prediction rule has more impact on clinical outcomes.[6]
The more intensively the prediction rule is implemented the more benefit will occur.[7]
Examples of prediction rules
Cardiovascular diseases
Acute MI / unstable angina
Risk Score | Year published | Purpose |
---|---|---|
TIMI risk score | 2000 | Unstable Angina |
TIMI risk score | 2000 | STEMI |
Morrow et al (TIME II substudy) [8] | 2001 | Predicting mortality in STEMI |
Silver et al [9] | 1994 | To predict preserved left ventricular ejection fraction in patients after MI |
The GRACE risk score | 2003 | For risk of death in NSTEMI |
ACI-TIPI risk score [10] | 1991 | To assess the likelihood of patients having acute cardiac ischemia and thus the appropriateness of admitting them to the coronary care unit (CCU). |
Goldman algorithm [11] | 1988 | To predict the likelihood that a patient has a myocardial infarction. |
Hathaway et al [12] | 1998 | Prognosis based on initial ECG |
Selker et al [13] | 1991 | Risk of death in AMI |
Piombo et al [14] | 2003 | To stratify risk in unstable angina. |
Solomon et al [15] | 2001 | To identify which patients benefit from immediate coronary angiography and revascularization. |
Sabatine et al [16] | 2001 | Benefit with glycoprotein IIb/IIIa inhibitor therapy in patients with unstable angina pectoris. |
Stroke, Atrial fibrillation
Risk Score | Year published | Purpose |
---|---|---|
HAS-BLED | 2010 | Bleeding risk stratification score for those on oral anticoagulants in atrial fibrillation. |
ABCD 2 [17] | 2010 | Stroke risk with TIA |
CHA2DS2-VASc Score | 2009 | To predict clinical risk of stroke and thromboembolism in atrial fibrillation. |
Schnabel et al [18] Framingham Heart Study [2] | 2009 | 10 years risk of Atrial fibrillation |
HEMORR2HAGES [19] | 2006 | Bleeding Risk Score |
ABCD [20] | 2005 | Stroke risk after TIA |
van Walraven et al [21] | 2003 | Stroke risk - atrial fib |
Wang et al [22] | 2003 | To predict 1 year stroke mortality |
Counsel et al [23] | 2003 | Acute stroke prognosis (6 variable score) |
Wang et al [24] Framingham Heart Study [3] | 2003 | Stroke after Atrial fibrillation |
Wang et al [24] Framingham Heart Study [4] | 2003 | Stroke or death after Atrial fibrillation. |
Efstathiou et al [25] | 2002 | To differentiate Ischemic from hemorrhagic stroke |
Lumley et al [26] | 2002 | To predict stroke in elderly. |
CHADS2 | 2001 | Risk of stroke with AFIB |
Baird et al [27] | 2001 | To predict stroke recovery. |
Wang et al [28] | 2001 | To predict 30 days stroke mortality |
NIH Stroke Scale [29] | 1999 | To predicts the likelihood of a patient's recovery after stroke. |
Cincinnati stroke scale [30] | 1999 | Stroke diagnosis |
D'Agostino et al [31] Framingham Heart Study [5] | 1994 | Risk of stroke |
Deep veinous thrombosis & PE
Risk Score | Year published | Purpose |
Wells score | 2000 | Pulmonary embolism |
Hypertension, Lipid & Screening
Risk Score | Year published | Purpose |
Parikh et al [32] Framingham Heart Study [6] | 2008 | Hypertension Risk Score |
NCEP ATP III [33] | 2001 | Screening: lipid guideline |
Krijnen et al [34] | 1998 | To predict renal artery stenosis. |
Murabito et al [35] Framingham Heart Study [7] | 1997 | Intermittent claudication |
Chest pain and CAD
Risk Score | Year published | Purpose |
Panic Screening Score [36] | 2011 | Screening score to improve recognition of panic-like anxiety in emergency department (ED) patients with unexplained chest pain. |
Pencina et al [37] Framingham Heart Study [8] | 2009 | 30-year risk of cardiovascular disease. |
North American Chest Pain Rule [38] | 2008 | For early discharge of patients with chest pain. |
Vancouver chest pain rule [39] | 2006 | For early discharge of patients with chest pain. |
Wilson et al [40] Framingham Heart Study [9] | 1998 | 10-year risk of coronary heart disease. |
Diamond et al [41] | 1979 | Pretest probability of CAD. |
Angioplasty
Risk Score | Year published | Purpose |
Halkin et al [42] | 2005 | Angioplasty complication rate |
Fortescue et al [43] | 2003 | Angioplasty complication rate |
Singh et al [44] | 2002 | Angioplasty complication rate |
Resnic et al [45] | 2001 | Angioplasty complication rate |
Moscucci et al [46] | 2001 | Mortality after angioplasty. |
Valve and endocarditis
Risk Score | Year published | Purpose |
---|---|---|
Otto et al [47] | 1988 | AV replacement in aortic stenosis. |
Koplan et al [48] | 2003 | To predict the need for permanent pacing after cardiac valve surgery. |
Hasbun et al [49] | 2003 | Endocarditis prognosis. |
Others
Risk Score | Year published | Purpose |
Feringa et al [50] | 2007 | Peripheral vascular disease prognosis. |
Other organ system
Risk Score | Purpose |
Gastroentestinal diseases | |
Ranson criteria | To predict the severity of acute pancreatitis. |
Tygerberg score | To diffrentiate tuberculosis as a cause of pericarditis. |
Orthopedic diseases | |
QFracture score | Osteoporosis [10] |
Ottawa ankle rules | To decide for offering Xray to patient with foot or ankle pain. |
Rules predicting complications in diseased patients | |
---|---|
Risk Score | Purpose |
Pneumonia severity index | To calculate the probability of morbidityand mortality among patients with community acquired pneumonia. |
CURB-65 | To predict mortality in community-acquired pneumonia. |
MELD | To assess the severity of chronic liver disease. |
Apnea-hypopnea index | To assess the overall severity of sleep apnea. |
Amar et al [51] | To calculate pulmonary complications after thoracic surgery for primary Lung Cancer |
- Various rules are used in the Intensive Care Unit and are grouped as ICU scoring systems (Glasgow coma scale, Pediatric Glasgow Coma Scale, APACHE II, SAPS II, PIM2).
References
- ↑ McGinn TG, Guyatt GH, Wyer PC, Naylor CD, Stiell IG, Richardson WS (2000). "Users' guides to the medical literature: XXII: how to use articles about clinical decision rules. Evidence-Based Medicine Working Group". JAMA. 284 (1): 79–84. PMID 10872017.
- ↑ Friedmann PD, Brett AS, Mayo-Smith MF (1996). "Differences in generalists' and cardiologists' perceptions of cardiovascular risk and the outcomes of preventive therapy in cardiovascular disease". Ann. Intern. Med. 124 (4): 414–21. PMID 8554250.
- ↑ Reilly BM, Evans AT (2006). "Translating clinical research into clinical practice: impact of using prediction rules to make decisions". Ann. Intern. Med. 144 (3): 201–9. PMID 16461965.
- ↑ Lee TH, Pearson SD, Johnson PA; et al. (1995). "Failure of information as an intervention to modify clinical management. A time-series trial in patients with acute chest pain". Ann. Intern. Med. 122 (6): 434–7. PMID 7856992.
- ↑ Poses RM, Cebul RD, Wigton RS (1995). "You can lead a horse to water--improving physicians' knowledge of probabilities may not affect their decisions". Medical decision making : an international journal of the Society for Medical Decision Making. 15 (1): 65–75. PMID 7898300.
- ↑ Marrie TJ, Lau CY, Wheeler SL, Wong CJ, Vandervoort MK, Feagan BG (2000). "A controlled trial of a critical pathway for treatment of community-acquired pneumonia. CAPITAL Study Investigators. Community-Acquired Pneumonia Intervention Trial Assessing Levofloxacin". JAMA. 283 (6): 749–55. PMID 10683053.
- ↑ Yealy DM, Auble TE, Stone RA; et al. (2005). "Effect of increasing the intensity of implementing pneumonia guidelines: a randomized, controlled trial". Ann. Intern. Med. 143 (12): 881–94. PMID 16365469.
- ↑ Morrow DA, Antman EM, Giugliano RP, Cairns R, Charlesworth A, Murphy SA, de Lemos JA, McCabe CH, Braunwald E (2001). "A simple risk index for rapid initial triage of patients with ST-elevation myocardial infarction: an InTIME II substudy". Lancet. 358 (9293): 1571–5. doi:10.1016/S0140-6736(01)06649-1. PMID 11716882. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Silver MT, Rose GA, Paul SD, O'Donnell CJ, O'Gara PT, Eagle KA (1994). "A clinical rule to predict preserved left ventricular ejection fraction in patients after myocardial infarction". Ann. Intern. Med. 121 (10): 750–6. PMID 7944052. Unknown parameter
|month=
ignored (help);|access-date=
requires|url=
(help) - ↑ Selker HP, Griffith JL, D'Agostino RB (1991). "A tool for judging coronary care unit admission appropriateness, valid for both real-time and retrospective use. A time-insensitive predictive instrument (TIPI) for acute cardiac ischemia: a multicenter study". Med Care. 29 (7): 610–27. PMID 2072767. Unknown parameter
|month=
ignored (help);|access-date=
requires|url=
(help) - ↑ Goldman L, Cook EF, Brand DA, Lee TH, Rouan GW, Weisberg MC, Acampora D, Stasiulewicz C, Walshon J, Terranova G (1988). "A computer protocol to predict myocardial infarction in emergency department patients with chest pain". N. Engl. J. Med. 318 (13): 797–803. doi:10.1056/NEJM198803313181301. PMID 3280998. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Hathaway WR, Peterson ED, Wagner GS, Granger CB, Zabel KM, Pieper KS, Clark KA, Woodlief LH, Califf RM (1998). "Prognostic significance of the initial electrocardiogram in patients with acute myocardial infarction. GUSTO-I Investigators. Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries". JAMA. 279 (5): 387–91. PMID 9459474. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Selker HP, Griffith JL, D'Agostino RB (1991). "A time-insensitive predictive instrument for acute myocardial infarction mortality: a multicenter study". Med Care. 29 (12): 1196–211. PMID 1745078. Unknown parameter
|month=
ignored (help);|access-date=
requires|url=
(help) - ↑ Piombo AC, Gagliardi JA, Guetta J, Fuselli J, Salzberg S, Fairman E, Bertolasi C (2003). "A new scoring system to stratify risk in unstable angina". BMC Cardiovasc Disord. 3: 8. doi:10.1186/1471-2261-3-8. PMC 194644. PMID 12930562. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Solomon DH, Stone PH, Glynn RJ, Ganz DA, Gibson CM, Tracy R, Avorn J (2001). "Use of risk stratification to identify patients with unstable angina likeliest to benefit from an invasive versus conservative management strategy". J. Am. Coll. Cardiol. 38 (4): 969–76. PMID 11583866. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Sabatine MS, Januzzi JL, Snapinn S, Théroux P, Jang IK (2001). "A risk score system for predicting adverse outcomes and magnitude of benefit with glycoprotein IIb/IIIa inhibitor therapy in patients with unstable angina pectoris". Am. J. Cardiol. 88 (5): 488–92. PMID 11524055. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Giles MF, Rothwell PM (2010). "Systematic review and pooled analysis of published and unpublished validations of the ABCD and ABCD2 transient ischemic attack risk scores". Stroke. 41 (4): 667–73. doi:10.1161/STROKEAHA.109.571174. PMID 20185786.
- ↑ Schnabel RB, Sullivan LM, Levy D, Pencina MJ, Massaro JM, D'Agostino RB, Newton-Cheh C, Yamamoto JF, Magnani JW, Tadros TM, Kannel WB, Wang TJ, Ellinor PT, Wolf PA, Vasan RS, Benjamin EJ (2009). "Development of a risk score for atrial fibrillation (Framingham Heart Study): a community-based cohort study". Lancet. 373 (9665): 739–45. doi:10.1016/S0140-6736(09)60443-8. PMC 2764235. PMID 19249635. Retrieved 2012-05-14. Unknown parameter
|month=
ignored (help) - ↑ Gage BF, Yan Y, Milligan PE, Waterman AD, Culverhouse R, Rich MW, Radford MJ (2006). "Clinical classification schemes for predicting hemorrhage: results from the National Registry of Atrial Fibrillation (NRAF)". Am. Heart J. 151 (3): 713–9. doi:10.1016/j.ahj.2005.04.017. PMID 16504638. Retrieved 2012-05-16. Unknown parameter
|month=
ignored (help) - ↑ Rothwell PM, Giles MF, Flossmann E, Lovelock CE, Redgrave JN, Warlow CP; et al. (2005). "A simple score (ABCD) to identify individuals at high early risk of stroke after transient ischaemic attack". Lancet. 366 (9479): 29–36. doi:10.1016/S0140-6736(05)66702-5. PMID 15993230. Review in: Evid Based Nurs. 2006 Jan;9(1):26 Review in: ACP J Club. 2006 Jan-Feb;144(1):24 Review in: Evid Based Med. 2006 Feb;11(1):27
- ↑ van Walraven C, Hart RG, Wells GA, Petersen P, Koudstaal PJ, Gullov AL; et al. (2003). "A clinical prediction rule to identify patients with atrial fibrillation and a low risk for stroke while taking aspirin". Arch Intern Med. 163 (8): 936–43. doi:10.1001/archinte.163.8.936. PMID 12719203. Review in: ACP J Club. 2004 Jan-Feb;140(1):25
- ↑ Wang Y, Lim LL, Heller RF, Fisher J, Levi CR (2003). "A prediction model of 1-year mortality for acute ischemic stroke patients". Arch Phys Med Rehabil. 84 (7): 1006–11. PMID 12881825.
- ↑ Counsel C, Dennis MS, Lewis S, Warlow C, FOOD Trial Collaboration. Feed Or Ordinary Diet (2003). "Performance of a statistical model to predict stroke outcome in the context of a large, simple, randomized, controlled trial of feeding". Stroke. 34 (1): 127–33. PMID 12511763.
- ↑ 24.0 24.1 Wang TJ, Massaro JM, Levy D, Vasan RS, Wolf PA, D'Agostino RB, Larson MG, Kannel WB, Benjamin EJ (2003). "A risk score for predicting stroke or death in individuals with new-onset atrial fibrillation in the community: the Framingham Heart Study". JAMA. 290 (8): 1049–56. doi:10.1001/jama.290.8.1049. PMID 12941677. Retrieved 2012-05-14. Unknown parameter
|month=
ignored (help) - ↑ Efstathiou SP, Tsioulos DI, Zacharos ID, Tsiakou AG, Mitromaras AG, Mastorantonakis SE; et al. (2002). "A new classification tool for clinical differentiation between haemorrhagic and ischaemic stroke". J Intern Med. 252 (2): 121–9. PMID 12190887.
- ↑ Lumley T, Kronmal RA, Cushman M, Manolio TA, Goldstein S (2002). "A stroke prediction score in the elderly: validation and Web-based application". J Clin Epidemiol. 55 (2): 129–36. PMID 11809350.
- ↑ Baird AE, Dambrosia J, Janket S, Eichbaum Q, Chaves C, Silver B; et al. (2001). "A three-item scale for the early prediction of stroke recovery". Lancet. 357 (9274): 2095–9. PMID 11445104.
- ↑ Wang Y, Lim LL, Levi C, Heller RF, Fischer J (2001). "A prognostic index for 30-day mortality after stroke". J Clin Epidemiol. 54 (8): 766–73. PMID 11470384.
- ↑ Adams HP, Davis PH, Leira EC, Chang KC, Bendixen BH, Clarke WR; et al. (1999). "Baseline NIH Stroke Scale score strongly predicts outcome after stroke: A report of the Trial of Org 10172 in Acute Stroke Treatment (TOAST)". Neurology. 53 (1): 126–31. PMID 10408548.
- ↑ Kothari RU, Pancioli A, Liu T, Brott T, Broderick J (1999). "Cincinnati Prehospital Stroke Scale: reproducibility and validity". Ann Emerg Med. 33 (4): 373–8. PMID 10092713.
- ↑ D'Agostino RB, Wolf PA, Belanger AJ, Kannel WB (1994). "Stroke risk profile: adjustment for antihypertensive medication. The Framingham Study". Stroke. 25 (1): 40–3. PMID 8266381. Unknown parameter
|month=
ignored (help);|access-date=
requires|url=
(help) - ↑ Parikh NI, Pencina MJ, Wang TJ, Benjamin EJ, Lanier KJ, Levy D, D'Agostino RB, Kannel WB, Vasan RS (2008). "A risk score for predicting near-term incidence of hypertension: the Framingham Heart Study". Ann. Intern. Med. 148 (2): 102–10. PMID 18195335. Unknown parameter
|month=
ignored (help);|access-date=
requires|url=
(help) - ↑ "Executive Summary of The Third Report of The National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, And Treatment of High Blood Cholesterol In Adults (Adult Treatment Panel III)". JAMA. 285 (19): 2486–97. 2001. PMID 11368702. Retrieved 2012-05-16. Unknown parameter
|month=
ignored (help) - ↑ Krijnen P, van Jaarsveld BC, Steyerberg EW, Man in 't Veld AJ, Schalekamp MA, Habbema JD (1998). "A clinical prediction rule for renal artery stenosis". Ann. Intern. Med. 129 (9): 705–11. PMID 9841602. Unknown parameter
|month=
ignored (help);|access-date=
requires|url=
(help) - ↑ Murabito JM, D'Agostino RB, Silbershatz H, Wilson WF (1997). "Intermittent claudication. A risk profile from The Framingham Heart Study". Circulation. 96 (1): 44–9. PMID 9236415. Retrieved 2012-05-14. Unknown parameter
|month=
ignored (help) - ↑ Foldes-Busque G, Fleet R, Poitras J, Chauny JM, Belleville G, Denis I, Diodati JG, Pelland MÈ, Lessard MJ, Marchand A (2011). "Preliminary investigation of the Panic Screening Score for emergency department patients with unexplained chest pain". Acad Emerg Med. 18 (3): 322–5. doi:10.1111/j.1553-2712.2011.01009.x. PMID 21352398. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Pencina MJ, D'Agostino RB, Larson MG, Massaro JM, Vasan RS (2009). "Predicting the 30-year risk of cardiovascular disease: the framingham heart study". Circulation. 119 (24): 3078–84. doi:10.1161/CIRCULATIONAHA.108.816694. PMC 2748236. PMID 19506114. Retrieved 2012-05-14. Unknown parameter
|month=
ignored (help) - ↑ Hess EP, Wells GA, Jaffe A, Stiell IG (2008). "A study to derive a clinical decision rule for triage of emergency department patients with chest pain: design and methodology". BMC Emerg Med. 8: 3. doi:10.1186/1471-227X-8-3. PMC 2275746. PMID 18254973. Retrieved 2012-05-15.
- ↑ Christenson J, Innes G, McKnight D, Thompson CR, Wong H, Yu E, Boychuk B, Grafstein E, Rosenberg F, Gin K, Anis A, Singer J (2006). "A clinical prediction rule for early discharge of patients with chest pain". Ann Emerg Med. 47 (1): 1–10. doi:10.1016/j.annemergmed.2005.08.007. PMID 16387209. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Wilson PW, D'Agostino RB, Levy D, Belanger AM, Silbershatz H, Kannel WB (1998). "Prediction of coronary heart disease using risk factor categories". Circulation. 97 (18): 1837–47. PMID 9603539. Retrieved 2012-05-14. Unknown parameter
|month=
ignored (help) - ↑ Diamond GA, Forrester JS (1979). "Analysis of probability as an aid in the clinical diagnosis of coronary-artery disease". N. Engl. J. Med. 300 (24): 1350–8. doi:10.1056/NEJM197906143002402. PMID 440357. Retrieved 2012-05-16. Unknown parameter
|month=
ignored (help) - ↑ Halkin A, Singh M, Nikolsky E, Grines CL, Tcheng JE, Garcia E, Cox DA, Turco M, Stuckey TD, Na Y, Lansky AJ, Gersh BJ, O'Neill WW, Mehran R, Stone GW (2005). "Prediction of mortality after primary percutaneous coronary intervention for acute myocardial infarction: the CADILLAC risk score". J. Am. Coll. Cardiol. 45 (9): 1397–405. doi:10.1016/j.jacc.2005.01.041. PMID 15862409. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Fortescue EB, Kahn K, Bates DW (2003). "Major adverse outcomes after percutaneous transluminal coronary angioplasty: a clinical prediction rule". J Clin Epidemiol. 56 (1): 17–27. PMID 12589866. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Singh M, Lennon RJ, Holmes DR, Bell MR, Rihal CS (2002). "Correlates of procedural complications and a simple integer risk score for percutaneous coronary intervention". J. Am. Coll. Cardiol. 40 (3): 387–93. PMID 12142101. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Resnic FS, Ohno-Machado L, Selwyn A, Simon DI, Popma JJ (2001). "Simplified risk score models accurately predict the risk of major in-hospital complications following percutaneous coronary intervention". Am. J. Cardiol. 88 (1): 5–9. PMID 11423050. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Moscucci M, Kline-Rogers E, Share D, O'Donnell M, Maxwell-Eward A, Meengs WL, Kraft P, DeFranco AC, Chambers JL, Patel K, McGinnity JG, Eagle KA (2001). "Simple bedside additive tool for prediction of in-hospital mortality after percutaneous coronary interventions". Circulation. 104 (3): 263–8. PMID 11457742. Retrieved 2012-05-15. Unknown parameter
|month=
ignored (help) - ↑ Otto CM, Pearlman AS (1988). "Doppler echocardiography in adults with symptomatic aortic stenosis. Diagnostic utility and cost-effectiveness". Arch. Intern. Med. 148 (12): 2553–60. PMID 3143323. Retrieved 2012-05-16. Unknown parameter
|month=
ignored (help) - ↑ Koplan BA, Stevenson WG, Epstein LM, Aranki SF, Maisel WH (2003). "Development and validation of a simple risk score to predict the need for permanent pacing after cardiac valve surgery". J. Am. Coll. Cardiol. 41 (5): 795–801. PMID 12628725. Retrieved 2012-05-16. Unknown parameter
|month=
ignored (help) - ↑ Hasbun R, Vikram HR, Barakat LA, Buenconsejo J, Quagliarello VJ (2003). "Complicated left-sided native valve endocarditis in adults: risk classification for mortality". JAMA. 289 (15): 1933–40. doi:10.1001/jama.289.15.1933. PMID 12697795. Retrieved 2012-05-16. Unknown parameter
|month=
ignored (help) - ↑ Feringa HH, Bax JJ, Hoeks S, van Waning VH, Elhendy A, Karagiannis S, Vidakovic R, Schouten O, Boersma E, Poldermans D (2007). "A prognostic risk index for long-term mortality in patients with peripheral arterial disease". Arch. Intern. Med. 167 (22): 2482–9. doi:10.1001/archinte.167.22.2482. PMID 18071171. Retrieved 2012-05-16. Unknown parameter
|month=
ignored (help) - ↑ Amar D, Munoz D, Shi W, Zhang H, Thaler HT (2010). "A clinical prediction rule for pulmonary complications after thoracic surgery for primary lung cancer". Anesth. Analg. 110 (5): 1343–8. doi:10.1213/ANE.0b013e3181bf5c99. PMID 19861366. Retrieved 2012-05-14. Unknown parameter
|month=
ignored (help)