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Three Part Question

In [adults with suspected appendicitis] is [the alvarado scoring system] an [accurate diagnostic tool]

Clinical Scenario

A 20 year old male presents to the accident and emergency department with gradually worsening right iliac fossa pain. He states that the pain has been there for the past two days but has significantly increased over the past 12 hours. He can not recall any pain elsewhere in his abdomen previous to this pain. He complains of a decrease in appetite but has no nausea and has not vomited. On examination, his abdomen is soft and there is no evidence of rebound tenderness. He is afebrile and his basic laboratory tests show a normal WBC count. You wonder how likely it is that this patient has appendicitis and how best to manage this individual. You have seen numerous patients with an equivocal diagnosis of appendicitis and begin to think that a diagnostic tool in this area would be very useful to aid the management of such individuals. You wonder if a valid scoring system exists that could be used for this purpose.

Search Strategy

MEDLINE (1960-2008) and EMBASE
[(exp appendicitis OR appendicitis.mp OR acute appendicitis.mp OR exp acute abdomen OR acute abdomen.mp) AND (Alvarado.mp OR Alvarado scoring.mp)] LIMIT to Humans and English Language

Search Outcome

50 articles, of which 11 were relevant.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Al-Hashemy and Seleem, 2004,	125 consecutive patients with provisional diagnosis of appendicitis	Diagnostic	Value of Modified Alvarado score in predicting appendicitis	Sensitivity of Alvarado score 53.8%, specificity 80%. (males sens 56.4%, spec 100%, females sens 48%, spec 62.5%)	Surgeons not blinded to score even though they were supposed to make an independent diagnosis. There are no tables of data and results are incomplete.
Shrivastava et al, 2004,	100 patients who were operated on with the provisional diagnosis of appendicitis	Diagnostic	Value of Unmodified Alvarado score in predicting appendicitis	Overall sensitivity 77.6%, specificity 52.4% (males 84%, females 57.8%). Sensitivity of score ≤ 6 92%, specificity 60%. PPV 81%, NPV 80.8%	Does not take into account the patient group who were not sent for surgery.
Khan and Rehman 2005,	100 consecutive patients with suspected appendicitis.	Diagnostic	Value of Unmodified Alvarado score in predicting appendicitis	Negative appendicectomy rate 15.6%, Positive predictive value 84.3% (males 88%, females 82.1%)	No calculation of sensitivity or specificity and no statistical analysis of difference to normal negative appendicectomy rate.
Tade AO, 2007,	100 consecutive patients who presented with RIF pain	Diagnostic	Value of Unmodified Alvarado score in predicting appendicitis	Sensitivity and negative predictive value for a score of <5 100%, specificity and PPV for a score of 10 was 100%	No data table to summarise all sensitivity and specificity values. The referenced gold standard was not applied to all patient groups.
Abdeldaim et al, 2007,	214 consecutive patients with RIF pain	Retrospective diagnostic	Value of Unmodified Alvarado score in predicting appendicitis	PPV male 96%, female 77%NPV male 92% female 77%	Retrospective study. No basic data table. No explanation of statistical methods

Comment(s)

Both the modified and unmodified Alvarado scoring systems have been evaluated in the above literature. Both show similar sensitivity and specificity. However, the modified score is more feasible in most laboratories and therefore may be of more use clinically.

The Alvarado scoring system is a cheap, convenient and extremely useful diagnostic tool for aiding the diagnosis of appendicitis. It has been shown to be consistently sensitive and specific and should be used as a routine part of the assessment of any patient with RLQ pain. In all the studies shown above, not a single patient with a score of <5 had appendicitis. This shows that the scoring system is so sensitive that it can rule out appendicitis if the score is below this value. It is limited however, in its use with regards to females. There is a far higher false positive rate in this patient group due to the added complications of gynaecological problems. However, it has been found that when women undergo USS before surgery to rule out pelvic problems, the false positive rate returns to that of males. Therefore, it may also be a useful tool in females, provided it is combined with a method to help rule out pelvic pathology first.

Clinical Bottom Line

The Alvarado scoring system is an accurate diagnostic tool for appendicitis. A score of less than 5 is 100% sensitive for ruling out the diagnosis of appendicitis.

References

1. Owen TD, Williams H, Stiff G, Jenkinson LR, Rees BI. Evaluation of the Alvarado score in acute appendicitis. J R Soc Med. 1992 Feb;85(2):87-8.
2. Kalan M, Talbot D, Cunliffe WJ, Rich AJ. Evaluation of the modified Alvarado score in the diagnosis of acute appendicitis: a prospective study. Ann R Coll Surg Engl. 1994 Nov;76(6):418-9.
3. Malik AA, Wani NA. Continuing diagnostic challenge of acute appendicitis: evaluation through modified Alvarado score. Aust N Z J Surg. 1998 Jul;68(7):504-5.
4. Chan MY, Teo BS, Ng BL. The Alvarado score and acute appendicitis. Ann Acad Med Singapore. 2001 Sep;30(5):510-2.
5. Bhattacharjee PK, Chowdhury T, Roy D. Prospective evaluation of modified Alvarado score for diagnosis of acute appendicitis. J Indian Med Assoc. 2002 May;100(5):310-1, 314.
6. Chan MY, Tan C, Chiu MT, Ng YY. Alvarado score: an admission criterion in patients with right iliac fossa pain. The Surgeon: Surg J R Coll Surg Edinb Irel. 2003 Feb;1(1):39-41.
7. Al-Hashemy AM, Seleem MI. Appraisal of the modified Alvarado Score for acute appendicits in adults. Saudi Med J. 2004 Sep;25(9):1229-31.
8. Shrivastava UK, Gupta A, Sharma D. Evaluation of the Alvarado score in the diagnosis of acute appendicitis. Trop Gastroenterol. 2004 Oct-Dec;25(4):184-6.
9. Khan I, ur Rehman A. Application of alvarado scoring system in diagnosis of acute appendicitis. J Ayub Med Coll Abbottabad. 2005 Jul-Sep;17(3):41-4.
10. Tade AO. Evaluation of Alvarado score as an admission criterion in patients with suspected diagnosis of acute appendicitis. West Afr J Med. 2007 Jul-Sep;26(3):210-2.
11. Abdeldaim Y, Mahmood S, Mc Avinchey D. The Alvarado score as a tool for diagnosis of acute appendicitis. Ir Med J. 2007 Jan;100(1):342.