Abstract
BACKGROUND: Sore throat is very common in general practice and is usually caused by viral infection. Nevertheless, up to 95% of patients may be treated with antibiotics. Previous diagnostic systems have not transferred well from one area to another because of an inability to allow for changing prevalence of streptococcus. AIM: To measure the occurrence rates of symptoms and signs in sore throat patients with and without streptococcal infection, and to develop a Bayesian scoring system which is easily adapted for prevalence to predict if patients have bacterial infection. METHOD: Occurrence rates of symptoms and signs were measured for 206 patients with sore throat symptoms over a 3-year period. Bayesian probability scores (B-scores) for each data item were calculated from the ocurrence rates in the patients with positive throat cultures for group A streptococci and the rates in patients with negative throat cultures. The B-score values were then used to predict the probability of positive culture for each patient. RESULTS: The streptococcal throat B-score system predicted positive culture with a sensitivity of 71% and a specificity of 71%. In comparison, the unaided general practitioners predicted infection with a sensitivity of 61% and a specificity of 65%. If the B-score prediction had been used to decide on treatment, more patients with streptococci present on culture would have been treated with antibiotic (71% instead of 68%) and appreciably fewer patients with negative streptococcal cultures would have been treated (29% instead of 59%). CONCLUSION: Use of the B-score system could result in significant savings in unnecessary antibiotic prescription, and unnecessary throat swab cultures, while achieving better levels of treatment.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Breese B. B. A simple scorecard for the tentative diagnosis of streptococcal pharyngitis. Am J Dis Child. 1977 May;131(5):514–517. doi: 10.1001/archpedi.1977.02120180028003. [DOI] [PubMed] [Google Scholar]
- Brien J. H., Bass J. W. Streptococcal pharyngitis: optimal site for throat culture. J Pediatr. 1985 May;106(5):781–783. doi: 10.1016/s0022-3476(85)80354-1. [DOI] [PubMed] [Google Scholar]
- Burke P., Bain J., Lowes A., Athersuch R. Rational decisions in managing sore throat: evaluation of a rapid test. Br Med J (Clin Res Ed) 1988 Jun 11;296(6637):1646–1649. doi: 10.1136/bmj.296.6637.1646. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dobbs F. F., Fleming D. M. A simple scoring system for evaluating symptoms, history and urine dipstick testing in the diagnosis of urinary tract infection. J R Coll Gen Pract. 1987 Mar;37(296):100–104. [PMC free article] [PubMed] [Google Scholar]
- Herz M. J. Antibiotics and the adult sore throat--an unnecessary ceremony. Fam Pract. 1988 Sep;5(3):196–199. doi: 10.1093/fampra/5.3.196. [DOI] [PubMed] [Google Scholar]
- Hjortdahl P., Laerum E., Mowinckel P. Clinical assessment of pharyngitis in general practice. Scand J Prim Health Care. 1988 Nov;6(4):219–223. doi: 10.3109/02813438809009320. [DOI] [PubMed] [Google Scholar]
- McMillan J. A., Sandstrom C., Weiner L. B., Forbes B. A., Woods M., Howard T., Poe L., Keller K., Corwin R. M., Winkelman J. W. Viral and bacterial organisms associated with acute pharyngitis in a school-aged population. J Pediatr. 1986 Nov;109(5):747–752. doi: 10.1016/s0022-3476(86)80687-4. [DOI] [PubMed] [Google Scholar]
- Platts P., Manson P. G., Finch R. Acute pharyngitis: a symptom scorecard and microbiological diagnosis. Br Med J (Clin Res Ed) 1982 Feb 6;284(6313):387–388. doi: 10.1136/bmj.284.6313.387. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Poses R. M., Cebul R. D., Collins M., Fager S. S. The importance of disease prevalence in transporting clinical prediction rules. The case of streptococcal pharyngitis. Ann Intern Med. 1986 Oct;105(4):586–591. doi: 10.7326/0003-4819-105-4-586. [DOI] [PubMed] [Google Scholar]
- Touw-Otten F. W., Johansen K. S. Diagnosis, antibiotic treatment and outcome of acute tonsillitis: report of a WHO Regional Office for Europe study in 17 European countries. Fam Pract. 1992 Sep;9(3):255–262. doi: 10.1093/fampra/9.3.255. [DOI] [PubMed] [Google Scholar]
- Wald E. R. Management of pharyngitis revisited. J Fam Pract. 1988 Apr;26(4):367–368. [PubMed] [Google Scholar]
- Whitfield M. J., Hughes A. O. Penicillin in sore throat. Practitioner. 1981 Feb;225(1352):234–239. [PubMed] [Google Scholar]