***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: BACKGROUND Therapy with antibiotics influences recovery only in selected cases of COPD exacerbations . We evaluated the efficacy and safety of procalcitonin guidance compared to st and ard therapy with antibiotic prescriptions in patients experiencing exacerbations of COPD . METHODS A total of 208 consecutive patients requiring hospitalization for COPD exacerbation were r and omized at the index exacerbation to procalcitonin-guided or st and ard antibiotic therapy . Patients receiving procalcitonin-guided therapy were treated with antibiotics according to serum procalcitonin levels ; st and ard-therapy patients received antibiotics according to the attending physician . The primary outcome was the antibiotic exposure at the index exacerbation and the subsequent antibiotic requirement for COPD exacerbation within 6 months . Secondary outcomes were clinical recovery , symptom scores , length of hospitalization , ICU stay , death , lung function , exacerbation rate , and time to next exacerbation . RESULTS At the index exacerbation , procalcitonin guidance reduced antibiotic prescription ( 40 % vs 72 % , respectively ; p < 0.0001 ) and antibiotic exposure ( relative risk [ RR ] , 0.56 ; 95 % confidence interval [ CI ] , 0.43 to 0.73 ; p < 0.0001 ) compared to st and ard therapy . Moreover , procalcitonin guidance at the index exacerbation allowed a significant sustained reduction in total antibiotic exposure for up to 6 months ( RR , 0.76 ; 95 % CI , 0.64 to 0.92 ; p = 0.004 ) . Clinical outcome and improvement in FEV(1 ) at 14 days and 6 months did not differ between groups . Within 6 months , the exacerbation rate ( 0.62 vs 0.64 , respectively ) , the rehospitalization rate ( 0.21 vs 0.24 , respectively ) , and mean ( + /- SD ) time to the next exacerbation ( 70.0 + /- 46.1 vs 70.4 + /- 51.9 days , respectively ; p = 0.523 ) were similar in both groups . CONCLUSIONS Procalcitonin guidance for exacerbations of COPD offers a sustained advantage over st and ard therapy in reducing antibiotic use for up to 6 months with a number-needed-to-treat of 3 BACKGROUND The value of azithromycin for treatment of acute bronchitis is unknown , even though this drug is commonly prescribed . We have investigated this question in a r and omised , double-blind , controlled trial . METHODS Adults diagnosed with acute bronchitis , without evidence of underlying lung disease , were r and omly assigned  azithromycin ( n=112 ) or vitamin C  ( n=108 ) for 5 days ( total dose for each 1.5 g ) . All individuals were also given liquid dextromethorphan and albuterol inhaler with a spacer . The primary outcome was improvement in health-related quality of life at 7 days ; an important difference was defined as 0.5 or greater . Analysis was by intention to treat . FINDINGS The study was stopped by the data -monitoring and safety committee when 220 patients had been recruited . On day 7 , the adjusted difference in health-related quality of life was small and not significant ( difference 0.03 [ 95 % CI -0.20 to 0.26 ] , p=0.8 ) . 86 ( 89 % ) of 97 patients in the azithromycin group and 82 ( 89 % ) of 92 in the vitamin C group had returned to their usual activities by day 7 ( difference 0.5 % [ -10 % to 9 % ] , p>0.9 ) . There were no differences in the frequency of adverse effects ; three patients in the vitamin C group discontinued the study medicine because of perceived adverse effects , compared with none in the azithromycin group . Most patients ( 81 % ) reported benefit from the albuterol inhaler . INTERPRETATION Azithromycin is no better than low-dose vitamin C for acute bronchitis . Further studies are needed to identify the best treatment for this disorder BACKGROUND Reduced duration of antibiotic treatment might contain the emergence of multidrug-resistant bacteria in intensive care units . We aim ed to establish the effectiveness of an algorithm based on the biomarker procalcitonin to reduce antibiotic exposure in this setting . METHODS In this multicentre , prospect i ve , parallel-group , open-label trial , we used an independent , computer-generated r and omisation sequence to r and omly assign patients in a 1:1 ratio to procalcitonin ( n=311 patients ) or control ( n=319 ) groups ; investigators were masked to assignment before , but not after , r and omisation . For the procalcitonin group , antibiotics were started or stopped based on predefined cut-off ranges of procalcitonin concentrations ; the control group received antibiotics according to present guidelines . Drug selection and the final decision to start or stop antibiotics were at the discretion of the physician . Patients were expected to stay in the intensive care unit for more than 3 days , had suspected bacterial infections , and were aged 18 years or older . Primary endpoints were mortality at days 28 and 60 ( non-inferiority analysis ) , and number of days without antibiotics by day 28 ( superiority analysis ) . Analyses were by intention to treat . The margin of non-inferiority was 10 % . This trial is registered with Clinical Trials.gov , number NCT00472667 . FINDINGS Nine patients were excluded from the study ; 307 patients in the procalcitonin group and 314 in the control group were included in analyses .  Mortality of patients in the procalcitonin group seemed to be non-inferior to those in the control group at day 28 ( 21.2 % [ 65/307 ] vs 20.4 % [ 64/314 ] ; absolute difference 0.8 % , 90 % CI -4.6 to 6.2 ) and day 60 ( 30.0 % [ 92/307 ] vs 26.1 % [ 82/314 ] ; 3.8 % , -2.1 to 9.7 ) . Patients in the procalcitonin group had significantly more days without antibiotics than did those in the control group ( 14.3 days [ SD 9.1 ] vs 11.6 days [ SD 8.2 ] ; absolute difference 2.7 days , 95 % CI 1.4 to 4.1 , p<0.0001 ) . INTERPRETATION A procalcitonin-guided strategy to treat suspected bacterial infections in non-surgical patients in intensive care units could reduce antibiotic exposure and selective pressure with no apparent adverse outcomes . FUNDING Assistance Publique-Hôpitaux de Paris , France , and Brahms , Germany CONTEXT In previous smaller trials , a procalcitonin ( PCT ) algorithm reduced antibiotic use in patients with lower respiratory tract infections ( LRTIs ) . OBJECTIVE To examine whether a PCT algorithm can reduce antibiotic exposure without increasing the risk for serious adverse outcomes . DESIGN , SETTING , AND PATIENTS A multicenter , noninferiority , r and omized controlled trial in emergency departments of 6 tertiary care hospitals in Switzerl and with an open intervention of 1359 patients with mostly severe LRTIs r and omized between October 2006 and March 2008 . INTERVENTION Patients were r and omized to administration of antibiotics based on a PCT algorithm with predefined cutoff ranges for initiating or stopping antibiotics ( PCT group ) or according to st and ard guidelines ( control group ) . Serum PCT  was measured locally in each hospital and instructions were Web-based . MAIN OUTCOME MEASURES Noninferiority of the composite adverse outcomes of death , intensive care unit admission , disease-specific complications , or recurrent infection requiring antibiotic treatment within 30 days , with a predefined noninferiority boundary of 7.5 % ; and antibiotic exposure and adverse effects from antibiotics . RESULTS The rate of overall adverse outcomes was similar in the PCT and control groups ( 15.4 % [ n = 103 ] vs 18.9 % [ n = 130 ] ; difference , -3.5 % ; 95 % CI , -7.6 % to 0.4 % ) . The mean duration of antibiotics exposure in the PCT vs control groups was lower in all patients ( 5.7 vs 8.7 days ; relative change , -34.8 % ; 95 % CI , -40.3 % to -28.7 % ) and in the subgroups of patients with community-acquired pneumonia ( n = 925 , 7.2 vs 10.7 days ; -32.4 % ; 95 % CI , -37.6 % to -26.9 % ) , exacerbation of chronic obstructive pulmonary disease ( n = 228 , 2.5 vs 5.1 days ; -50.4 % ; 95 % CI , -64.0 % to -34.0 % ) , and acute bronchitis ( n = 151 , 1.0 vs 2.8 days ; -65.0 % ; 95 % CI , -84.7 % to -37.5 % ) . Antibiotic-associated adverse effects were less frequent in the PCT group ( 19.8 % [ n = 133 ] vs 28.1 % [ n = 193 ] ; difference , -8.2 % ; 95 % CI , -12.7 % to -3.7 % ) . CONCLUSION In patients with LRTIs , a strategy of PCT guidance compared with st and ard guidelines result ed in similar rates of adverse outcomes , as well as lower rates of antibiotic exposure and antibiotic-associated adverse effects . TRIAL REGISTRATION is rct n.org Identifier : IS RCT N95122877 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 : For patients in intensive care units , sepsis is a common and potentially deadly complication and prompt initiation of appropriate antimicrobial therapy improves prognosis . The objective of this trial was to determine whether a strategy of antimicrobial spectrum escalation , guided by daily measurements of the biomarker procalcitonin , could reduce the time to appropriate ther 
    Output:
    
Use of procalcitonin to guide initiation and duration of antibiotic treatment in patients with ARI was not associated with higher mortality rates or treatment failure .
Antibiotic consumption was significantly reduced across different clinical setting s and ARI diagnoses .