***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract Objective : To assess three prescribing strategies for sore throat .  Design : R and omised follow up study . Setting : 11 general practice s in the South and West region . Subjects : 716 patients aged 4 years and over with sore throat and an abnormal physical sign in the throat ; 84 % had tonsillitis or pharyngitis . Patients were r and omised to three groups : prescription for antibiotics for 10 days ( group 1 , 246 patients ) ; no prescription ( group 2 , 230 patients ) ; or prescription for antibiotics if symptoms were not starting to settle after three days ( group 3 ; 238 patients ) . Main outcome measures : Duration of symptoms ; satisfaction and compliance with and perceived efficacy of antibiotics ; time off school or work . Outcomes were documented in 582 subjects ( 81 % ) . Results : Median duration of antibiotic use differed significantly in the three groups ( 10 v 0 v 0 days , P<0.001 ) ; 69 % of patients in group 3 did not use their prescription . The proportion of patients better by day 3 did not differ significantly ( 37 % v 35 % v 30 % , P=0.28 ) , nor did the duration of illness ( median 4 v 5 v 5 days , P=0.39 ) , days off work or school ( median 2 v 2 v 1 , P=0.13 ) , or proportion of patients satisfied ( 96 % v 90 % v 93 % , P=0.09 ) , although group 1 had fewer days of fever ( median 1 v 2 v 2 days , P=0.04 ) . More patients in group 1 thought the antibiotics were effective ( 87 % v 55 % v 60 % , P<0.001 ) and intended coming to the doctor in future attacks ( 79 % v 54 % v 57 % , P<0.001 ) . “ Legitimation ” of illness — to explain to work or school ( 60 % ) or family or friends (37%)–was an important reason for consultation . Patients who were more satisfied got better more quickly , and satisfaction related strongly to how well the doctor dealt with patient 's concerns . Conclusion : Prescribing antibiotics for sore throat only marginally affects the resolution of symptoms but enhances belief in antibiotics and intention to consult in future when compared with the acceptable strategies of no prescription or delayed prescription . Psychosocial factors are important in the decision to see a general practitioner and in predicting the duration of illness . Key messages Sore throat is one of the commonest presentations of upper respiratory illness to general practitioners , and attendance is increasing Prescribing antibiotics for sore throat does not reduce the extent and duration of symptoms Prescribing antibiotics enhances belief in antibiotics and intention to consult Legitimation of illness is an important reason for attending the doctor Satisfaction predicts duration of illness and closely relates to how well concerns are dealt with — unless patients are very ill , general practitioners should consider exploring concerns and should avoid or delay prescribing OBJECTIVE To vali date a score based on clinical symptoms and signs for the identification of group A Streptococcus ( GAS ) infection in general practice patients with score throat . DESIGN A single throat swab was used as the gold st and ard for diagnosing GAS infection . Clinical information was recorded by experienced family physicians on st and ardized encounter forms . Score criteria were identified by means of logistic regression modelling of data from patients enrolled in the first half of the study . The score was then vali date d among the remaining patients . SETTING University-affiliated family medicine centre in Toronto . PATIENTS A total of 521 patients aged 3 to 76 years presenting with a new upper respiratory tract infection from December 1995 to February 1997 . OUTCOME MEASURES Sensitivity , specificity and likelihood ratios for identification of GAS infection with the  score approach compared with throat culture . Proportion of patients prescribed antibiotics , throat culture use , and sensitivity and specificity with usual physician care and with score-based recommendations were compared . RESULTS A score was developed ranging in value from 0 to 4 . The sensitivity of the score  for identifying GAS infection was 83.1 % , compared with 69.4 % for usual physician care ( p = 0.06 ) ; the specificity values of the 2 approaches were similar . Among patients aged 3 to 14 years , the sensitivity of the score approach was higher than that of usual physician care ( 96.9 % v. 70.6 % ) ( p < 0.05 ) . The proportion of patients receiving initial antibiotic prescriptions would have been reduced 48 % by following score-based recommendations compared with observed physician prescribing ( p < 0.001 ) , without any increase in throat culture use . CONCLUSIONS An age-appropriate sore throat score identified GAS infection in children and adults with sore throat better than usual care by family physicians , with significant reductions in unnecessary prescribing of antibiotics . A r and omized trial comparing the 2 approaches is recommended to determine the ability of the score approach to reduce unnecessary prescribing of antibiotics during routine clinical encounters The data for medical decision analyses are often unreliable . Traditional sensitivity analysis --varying one or more probability or utility estimates from baseline values to see if the optimal strategy changes -- is cumbersome if more than two values are allowed to vary concurrently . This paper describes a practical method for probabilistic sensitivity analysis , in which uncertainties in all values are considered simultaneously . The uncertainty in each probability and utility is assumed to possess a probability distribution . For ease of application we have used a parametric model that permits each distribution to be specified by two values : the baseline estimate and a bound ( upper or lower ) of the 95 percent confidence interval . Following multiple simulations of the decision tree in which each probability and utility is r and omly assigned a value within its distribution , the following results are recorded : ( a ) the mean and st and ard deviation of the expected utility of each strategy ; ( b ) the frequency with which each strategy is optimal ; ( c ) the frequency with which each strategy " buys " or " costs " a specified amount of utility relative to the remaining strategies . As illustrated by an application to a previously published decision analysis , this technique is easy to use and can be a valuable addition to the armamentarium of the decision analyst BACKGROUND Primary prevention of acute rheumatic fever requires antibiotic treatment of acute streptococcal pharyngitis . In developing countries , clinicians must rely on clinical guidelines for presumptive treatment of streptococcal pharyngitis since bacterial culture and rapid diagnostic tests are not feasible . We evaluated the WHO Acute Respiratory Infection guideline in a large urban paediatric clinic in Egypt . METHODS Children between 2 and 13 years of age who had a sore throat and pharyngeal erythema were enrolled in the study . Clinical , historical , and demographic information was recorded and a throat culture for group A beta-haemolytic streptococci was done . Sensitivity ( % of true-positive throat cultures ) and specificity ( % of true-negative throat cultures ) were calculated for each clinical feature . The effect of various guidelines on correct presumptive treatment for throat-culture status was calculated . FINDINGS Of 451 children with pharyngitis , 107 ( 24 % ) had group A beta-haemolytic streptococci on throat culture . A purulent exu date was seen in 22 % ( 99/450 ) of these children and this sign was 31 % sensitive and 81 % specific for a positive culture . The WHO Acute Respiratory Infections ( ARI ) guidelines , which suggest treatment for pharyngeal exu date plus enlarged and tender cervical node , were 12 % sensitive and 94 % specific ; 13/107 children with a positive throat culture would correctly receive antibiotics and 323/344 with a negative throat culture would , correctly , not receive antibiotics . Based on our data we propose a modified guideline whereby exu date or large cervical nodes would indicate antibiotic treatment , and this guideline would be 84 % sensitive and 40 % specific ; 90/107 children with a positive throat culture would correctly receive antibiotics and 138/344 with a negative throat culture would , correctly , not receive antibiotics . INTERPRETATION The WHO ARI clinical guideline has a high specificity but low sensitivity that limits the unnecessary use of antibiotics , but does not treat 88 % of children with a positive streptococcal throat culture who are at risk of acute rheumatic fever . A modified guideline may be more useful in this population . Prospect i ve studies of treatment guidelines from many regions are needed to assess their use since the frequency of pharyngitis varies 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 Abstract Objective : To assess whether treatment with penicillin for three days and the traditional treatment for seven days were equally as effective at accelerating resolution of symptoms in patients with sore throat compared with placebo . Design : R and omised double blind placebo controlled trial . Setting : 43 family practice s in the Netherl and s. Participants : 561 patients , aged 15 - 60 years , with sore throat for less than seven days and at least three of the four Centor criteria —that is , history of fever , absence of cough , swollen tender anterior cervical lymph nodes , and tonsillar exu date . 142 patients were excluded for medical reasons and 73 needed penicillin .  Interventions : Patients were r and omly assigned to penicillin V for seven days , penicillin V for three days followed by placebo for four days , or placebo for seven days . Main outcome measures : Resolution of symptoms in the first week , eradication of bacteria after two weeks , and recurrences of sore throat after two , four , and six months . Results : Symptoms resolved 1.9 and 1.7 days earlier in patients taking penicillin for seven days than in those taking penicillin for three days or placebo respectively . Symptoms resolved 2.5 days earlier in patients with group A streptococci and 1.3 days earlier in patients with high colony counts of non-group A streptococci . 23 ( 13 % ) of the placebo group had to be given antibiotics later in the week because of clinical deterioration ; three developed a peritonsillar abscess . The eradication rate for group A streptococci was 72 % in the seven day penicillin group , 41 % in the three day penicillin group , and 7 % in the placebo group . Sore throat recurred more often in the three day penicillin group than in the seven day penicillin or placebo groups . Conclusion : Penicillin treatment for seven days was superior to treatment for three days or placebo in resolving symptoms of sore throat in patients with group A streptococcal pharyngitis and , possibly , in those with non-group A streptococcal pharyngitis The usefulness of clinical and laboratory findings for prediction of the presence of Group A streptococci on throat culture and of an increase in antistreptococcal antibodies  was investigated in 693 adult patients . Several findings were shown to increase the likelihood of streptococcal isolation , alone and in combination : tonsillar exu date , tonsillar enlargement , tender anterior cervical adenopathy , myalgias , and a positive throat culture in the preceding year . Compared with a frequency of 9.7 % in all patients , the probabilities of a positive culture were quite different ( ranging from 2 to 53 % ) in subgroups of patients with different combinations of these clinical findings . The results of a  leukocyte count and measurement of C-reactive protein added little additional predictive information . While clinical findings can never predict perfectly the results of a throat culture , they nevertheless can provide useful information — particularly in tending to “ rule out ” streptococcal infection — in adult patients with pharyngitis An optical immunoassay ( OIA ) has been reported to be more sensitive than conventional culture for the detection of Group A Streptococcus , eliminating the need for culture . We attempted to confirm the sensitivity and specificity through a labor 
    Output:
    
Little evidence suggests that treatment prevents glomerulonephritis ( 18 - 20 ) .