Intervention Review

You have free access to this content

Antibiotics for acute bronchitis

  1. Susan M Smith1,*,
  2. Tom Fahey1,
  3. John Smucny2,
  4. Lorne A Becker3

Editorial Group: Cochrane Acute Respiratory Infections Group

Published Online: 1 MAR 2014

Assessed as up-to-date: 15 JAN 2014

DOI: 10.1002/14651858.CD000245.pub3


How to Cite

Smith SM, Fahey T, Smucny J, Becker LA. Antibiotics for acute bronchitis. Cochrane Database of Systematic Reviews 2014, Issue 3. Art. No.: CD000245. DOI: 10.1002/14651858.CD000245.pub3.

Author Information

  1. 1

    RCSI Medical School, HRB Centre for Primary Care Research, Department of General Practice, Dublin 2, Ireland

  2. 2

    Palo Alto Medical Foundation, Dublin Center, Dublin, California, USA

  3. 3

    SUNY Upstate Medical University, Department of Family Medicine, Syracuse, New York, USA

*Susan M Smith, HRB Centre for Primary Care Research, Department of General Practice, RCSI Medical School, 123 St Stephens Green, Dublin 2, Ireland. susansmith@rcsi.ie. susmarsmith@gmail.com.

Publication History

  1. Publication Status: Edited (no change to conclusions)
  2. Published Online: 1 MAR 2014

SEARCH

 
Characteristics of included studies [ordered by study ID]
Brickfield 1986

MethodsDouble-blinded RCT


Participants52 adults (aged 18 to 65), with 2 weeks or less of lower respiratory infection with sputum production and no evidence of pneumonia clinically or radiographically. Drop-outs = 2/52


InterventionsEnteric-coated erythromycin 333 mg TID for 7 days versus placebo. Volunteers kept daily logs of multiple symptoms and were re-examined on day 8


OutcomesCough, sputum, fever, rhinorrhoea, chest discomfort, earache, sore throat, work disability, feeling ill and nausea daily; and clinical impression at follow-up


Notes29 volunteers had sputum cultured (27 = normal flora, 1 = H. influenza, 1 = S. pneumonia), outcomes not reported; 17/23 had more than 5 white blood cells (wbc) on Gram stain. Fewer than 30% of eligible patients opted to volunteer (most wanted antibiotics)


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot reported

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Dunlay 1987

MethodsDouble-blinded RCT


Participants63 adults (age 18 or older) with productive cough (mean duration = 7 days) and no clinical evidence of sinusitis or pneumonia. Drop-outs = 15 (6 - no follow-up at all; 9 - stopped taking pills during trial, authors state that no difference in results with or without the partial data from the latter 9)


InterventionsEnteric-coated erythromycin base, 333 mg TID for 10 days, versus placebo. Volunteers kept daily logs of 5 symptoms and had follow-up visit at approximately day 14


OutcomesDay cough, night cough, sputum production, congestion, sore throat, feeling poor, activity limitation and use of cough/cold medications daily; and cough, sputum and abnormal lung examination at follow-up


NotesOnly 20% of eligible patients enrolled in study (but unenrolled not different clinically per chart review). 13 erythromycin volunteers dropped out due to gastrointestinal (GI) side effects


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Evans 2002

MethodsDouble-blinded RCT


Participants220 adults (aged 18 to 88) with cough (with or without sputum) of 2 to 14 days duration


InterventionsAzithromycin 500 mg on day 1 and 250 mg daily on days 2 to 5 versus vitamin C 500 mg on day 1 and 250 mg daily on days 2 to 5 (total dose 1.5 G)


OutcomesAcute bronchitis health-related quality of life on day 3 and 7, proportion of participants who had returned to usual daily activities on days 3 and 7, side effects on days 3 and 7


Notes88% of eligible population included. Both groups received cough suppressant (dextromethorphan) and albuterol inhaler. No difference between groups in the use of albuterol inhaler at follow-up. 31/220 (14%) lost to follow-up. Timing of outcome at day 3 and day 7 (day 7 taken as outcome time in this review). Study was stopped by data-monitoring and safety committee because "outcomes were equivalent and there was sufficient precision to be confident that the likelihood of detecting a clinically meaningful difference with a larger sample was so small that continued enrolment of patients would be inappropriate"


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Franks 1984

MethodsDouble-blinded RCT


Participants67 patients aged 14 or older with less than 15 days of productive cough (in the absence of clinical pneumonitis). Excluded if could not produce sputum specimen for Gram stain. Drop-outs = 13/67


InterventionsTrimethoprim-sulfamethoxazole (160/800) BID for 7 days versus identical appearing placebo. Patients kept daily symptom logs. No follow-up visit


OutcomesCough, night cough, sputum production, general well-being, fever, work disability, use of adjunctive medications and side effects


NotesNo mention of per cent of eligible patients who refused enrolment


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Howie 1970

MethodsDouble-blinded RCT


Participants164 patients with a productive cough in conjunction with a cold or influenza-like illness that was not resolving after 2 days


InterventionsSelf-treatment with demethyl chlortetracycline (300 mg) or placebo BID for 5 days. Patients kept daily symptom logs. No initial or follow-up visits


OutcomesDuration of and presence on day 5 of cough, productive cough and purulent sputum; and duration of time off work


NotesThis was unpublished data about a subgroup of people with a cold or influenza-like illness; total number of people who treated themselves for a single episode of illness and returned symptom cards = 301


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Hueston 1994

MethodsDouble-blinded RCT


Participants23 adults (aged 18 to 65 years), with productive cough of less than 30 days duration and no clinical evidence of pneumonia. Drop-outs = 0


InterventionsErythromycin (250 mg) QID for 10 days versus identical-looking placebo. Patients kept daily symptom log and were re-examined on day 7 or 8


OutcomesCough, night cough, ability to perform normal work and general well-being daily and at follow-up; overall use of over-the-counter medications and side effects; and abnormal lung exam at follow-up


NotesThis was part of a 2 x 2 designed study comparing erythromycin + albuterol inhaler versus erythromycin + placebo versus albuterol inhaler + placebo versus placebo + placebo. The data extracted for this review were unpublished and limited to the erythromycin + placebo group versus the placebo + placebo group


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Unclear riskNot reported

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Unclear riskNot reported

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasUnclear riskNot reported

Kaiser 1996

MethodsDouble-blinded RCT


Participants75 patients (aged 16 to 64) with common cold and concomitant non-purulent tracheobronchitis and no evidence of sinusitis, pharyngitis, purulent bronchitis or pneumonia. Mean duration of illness 3 days


InterventionsAmoxicillin-clavulanic acid (375 mg TID for 5 days) versus identical-looking placebo. Patients re-evaluated on days 5 to 7


OutcomesPersistent or worse symptoms versus cure at follow-up


NotesThese were unpublished data about a subgroup of patients in a study of patients with common cold; total number of patients in study was 307


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNot reported

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

King 1996

MethodsDouble-blinded RCT


Participants91 patients (age 8 or older) with cough and sputum for up to 2 weeks, and no signs of sinusitis, otitis or pneumonia and no localised abnormal lung exam. All tested for Mycoplasma (one-half with negative serology excluded)


InterventionsErythromycin (250 mg QID for 10 days) versus identical-looking placebo. Volunteers kept daily logs and returned for follow-up visit at day 14 to 18


OutcomesCough, chest congestion, use of cough medication, general well-being, sleep and normal activities


NotesNo mention of eligible patients who refused to volunteer


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNot reported

Selective reporting (reporting bias)Unclear riskNot reported

Other biasHigh risk

Little 2005

MethodsRCT


Participants426, subgroup of 807 patients with acute uncomplicated lower respiratory tract infection. Inclusion criteria: aged 3 or more with uncomplicated LRTI for less than 21 days with cough as main symptom and at least 1 of sputum, chest pain, dyspnoea and wheeze


Interventions6-arm RCT: (1) no leaflet or antibiotic; (2) immediate antibiotics plus leaflet; (3) immediate antibiotics and no leaflet; (4) leaflet only; (5) leaflet and delayed antibiotic; (6) no leaflet and delayed antibiotics. Only data from the no treatment and immediate antibiotic groups included in the analysis. The antibiotic used was amoxicillin 250 mg TDS for 10 days (125 mg if less than 10 years) or erythromycin 250 mg QDS if penicillin allergic


OutcomesDaily diary for 3 weeks recording antipyretic use and 6 symptoms (cough dyspnoea, sputum production, well-being, sleep disturbance and activity disturbance); satisfaction questionnaire; belief in antibiotics scale; reported antibiotic use; note review for re-consultation


Notes25% lost to follow-up in no treatment and immediate antibiotic arms


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
High riskOpen design

Blinding (performance bias and detection bias)High risk

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Little 2013

MethodsRCT


Participants2061 patients aged 18 or over presenting with lower respiratory tract infection with cough duration less than 28 days


InterventionsAmoxicillin 1g 3 times daily for 7 days


OutcomesDuration of symptoms rated as moderately bad or worsening; mean symptom severity on days 2 to 4; proportion with symptoms resolved on day 7; new or worsening symptoms presenting clinically to GPs and adverse effects


NotesAdequately powered for subgroup analysis of patients aged over 60 (n = 595)


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low riskClinicians, patients and outcome assessors all blinded

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Low risk88% follow-up in both intervention and control groups

Selective reporting (reporting bias)Low risk

Other biasLow risk

Llor 2013

MethodsRCT (3 arms)


Participants420 patients age 18 to 70 years presenting with respiratory tract infection of 1 week evolution with cough as the predominant symptom. We included data from the antibiotic arm (137 patients) and the placebo arm (143 patients)


InterventionsIbuprofen or co-amoxiclav (dose 500 mg/125 mg)


OutcomesNumber days with frequent cough defined using a symptom diary. Secondary outcomes included clinically improved or cured, time to symptom resolution, median days with cough and adverse effects


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskPatients were randomised using a random number table into 3 blocks

Allocation concealment (selection bias)Low riskPatients were unaware of allocation and clinicians gave patients sealed containers so also unaware of allocation

Blinding (performance bias and detection bias)
All outcomes
Low riskPatients blinded and described as single-blind study. Tablets placed in sealed containers before dispatch by an independent pharmacist

Blinding (performance bias and detection bias)Low riskOutcomes collected in symptom diaries not seen by the investigators

Incomplete outcome data (attrition bias)
All outcomes
Low risk> 90% follow-up

Selective reporting (reporting bias)Low riskProtocol available

Other biasUnclear riskNot reported

Matthys 2000

MethodsDouble-blinded RCT


Participants294, a subgroup of 676 patients, mean age 39 (range 18 to 79 with acute bronchitis. Inclusion criteria: aged 18 years or older, symptoms of recent onset within last 5 days, nightly cough as main symptom (without at least 4 awakenings during the night) and without reduced FEV1 (more than 75% normal)


Interventions4-arm RCT: (1) myrtol standardised (phytotherapeutic extract); (2) cefuroxime 500 mg BID; (3) ambroxol (mucolytic agent); (4) placebo capsules. Only data from cefuroxime and placebo arms included in the analysis


OutcomesDaytime cough, night-time cough, type of cough and general well-being recorded by each participant; clinical examination at follow-up; "overall efficacy" judge by physician and participant; bronchial hyperreactivity; change in lung function; number of patients with relapse within 4 weeks; side effects. Physician assessment at 7 and 14 days; diary data on 3 follow-up time periods: day 7, 14, 15 to 28


NotesSecretolytics, mucolytics and antitussives prohibited during the study. Multiple hypothesis testing for all 4 treatment groups. 3/343 (0.9%) lost to follow-up


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Unclear riskNot reported

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Unclear riskNot reported

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Nduba 2008

MethodsTriple-blind, placebo-controlled RCT


Participants529 of 660 patients, mean age 31; 55% female. Productive cough for < 2 weeks, no serious medical co-morbidity and no antibiotic treatment in previous 2 weeks. All patients had HIV test and CXR at baseline. Excluded if CXR showed pneumonia or TB


InterventionsAmoxicillin 500 mg TDS for 7 days versus identical placebo tablet


OutcomesClinical cure at 14 days as measured by > 75% reduction in Acute Bronchitis Severity Score


NotesReported as first study of acute bronchitis treatment that used an equivalence design. Data available for HIV-positive patients but not included in the review


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskThe patients were randomised independently using a random number generator

Allocation concealment (selection bias)Low riskAntibiotic or placebo tablets identical in appearance, taste and smell were place in identical sealed opaque containers identifiable only with a unique study identifier

Blinding (performance bias and detection bias)
All outcomes
Low riskAll clinical and research staff were blinded to the allocation of participants and the allocation schedule was kept in the office of the Chief Research Pharmacist in the host institution

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Low risk> 85% follow-up for outcome data

Selective reporting (reporting bias)Unclear riskNo access to original protocol though selective reporting not apparent from trial description

Other biasLow risk

Scherl 1987

MethodsDouble-blinded RCT


Participants39 patients (older than 12 years old) with chief complaint of cough with purulent sputum and without: other known bacterial infection, flu-like syndrome, chief complaint of coryza or sore throat with minimal sputum, or chest radiograph consistent with pneumonia (not all had radiographs). Drop-outs = 8/31


InterventionsDoxycycline (100 mg BID on day 1 and 100 mg QID on days 2 to 7) versus placebo. Kept daily symptom log and had follow-up visit at day 14


OutcomesCough, sputum, feverishness, days missed from work or normal activity, chest pain, dyspnoea, side effects


NotesNo mention of eligible patients who refused to volunteer


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNot reported

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Stott 1976

MethodsDouble-blinded RCT


Participants212 patients aged > 14 years with cough and purulent sputum of up to 1 week. Excluded if chest exam was abnormal. Drop-outs = 5/212


InterventionsPatients given doxycycline or placebo (2 pills on day 1, then 1 daily for 9 days). Had follow-up after 1 week, if "satisfied with outcome" then treatment ended; if not, then completed remaining pills and continued to record symptoms. Volunteers completed daily symptom logs


OutcomesDay cough, night cough, "yellow spit", "clear spit", "off color", runny nose, sore throat, general aches, headache, vomiting, off work daily and at follow-up; clinical impression at follow-up; and illnesses over next 6 months


NotesNo difference in average pill consumption between groups (9.3 in doxycycline group versus 9.2 in placebo group). No mention of eligible patients who refused to volunteer


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Unclear riskNot reported

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Verheij 1994

MethodsDouble-blinded RCT


Participants158 adults (age 18 or older) with cough and purulent sputum, and no clinical sinusitis or pneumonia. Drop-outs = 13/158


InterventionsDoxycycline (200 mg on day 1 and 100 mg on days 2 to 10) versus placebo. Volunteers kept daily symptom log, and had follow-up visit on day 11


OutcomesDay cough, night cough, productive cough, feeling ill, impairment of activities and side effects daily; and clinical impression and auscultatory abnormalities at follow-up


Notes158/209 eligible patients entered study (no difference in age, sex or main symptoms between volunteers and unenrolled)


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasLow risk

Williamson 1984

MethodsDouble-blinded RCT


Participants74 adults (age 21 to 65) with cough and sputum, and concurrent upper respiratory tract infection, rhonchi, or history of fever; excluded for temperature more than 39.5, signs or symptoms of sinus infection, or chest radiograph with consolidation (but not ordered on all). Drop-outs = 5/74


InterventionsDoxycycline (100 mg BID on day 1, then 100 mg QID on days 2 to 7) versus identical-looking placebo. Kept daily symptom log, returned for follow-up visit on day 7 to 10. If not improved at follow-up, could get antibiotic prescription


OutcomesGeneral well-being, bother of cough, night cough, activity limitation, feverishness, sputum colour daily, doses of antitussives and clinical impression at follow-up


NotesNo mention of eligible patients who refused to volunteer


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk

Allocation concealment (selection bias)Low risk

Blinding (performance bias and detection bias)
All outcomes
Low risk

Blinding (performance bias and detection bias)Low risk

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Selective reporting (reporting bias)Unclear riskNot reported

Other biasUnclear riskNot reported

 
Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion

Bateiha 2002185 patients with acute respiratory tract infection from 2 health centres in Jordan. Assignment to antibiotic (azithromycin) was by means of alternation, not randomisation. At follow-up of 3 days, 1 week and 2 weeks, patients administered azithromycin or placebo did similarly in terms of the proportions improved or cured and in terms of duration of illness. The authors of the study conclude that routine use of antibiotics (azithromycin) in acute respiratory tract infection is unlikely to alter the course of the illness

Christ-Crain 2004RCT concerned with application of a diagnostic test (serum calcitonin precursor, procalcitonin) which is raised in bacterial infections. 243 patients admitted to hospital with suspected lower respiratory tract infections were randomly assigned standard care (standard group; n = 119) or procalcitonin-guided treatment (procalcitonin group; n = 124). On the basis of serum procalcitonin concentrations, use of antibiotics was more or less discouraged (< 0.1 µG/L or < 0.25 µG/L) or encouraged (greater than or equal to 0.5 µG/L or greater than or equal to 0.25 µG/L), respectively. Re-evaluation was possible after 6 to 24 hours in both groups. Primary endpoint was use of antibiotics. 59 (24%) has diagnosis of "acute bronchitis". Antibiotic use decreased in the procalcitonin group. Withholding antibiotic treatment based on procalcitonin measurement did not compromise patient outcome

Dowell 2001RCT of "delayed" versus "immediate" antibiotics for acute cough. Patients randomised to "delayed" arm were asked to wait a week before collecting their prescription. 55% of patients did not pick up their prescription. More patients were satisfied and "enabled" in the immediate treatment arm

Gordon 1974Participants were children with "symptoms referable to the respiratory tract", therefore likely many had upper respiratory infections (78% to 96% had runny nose, 74% to 83% had inflamed nasal mucosa)

Gottfarb 1994Post-randomisation exclusion of 23% of the sample because of laboratory evidence of pertussis infection. Outcomes not clearly reported. Inclusion criterion was cough, but not sputum production (therefore not consistent with definition used in the other studies). Age of participants in this study was 7 months to 7 years: the minimum age in the other studies was 8 (King 1996), 12 (Scherl 1987), or 14 or older (remaining studies)

Stephenson 1989Participants were adults with upper respiratory infection. Not all had cough, and no information available on the subgroup of patients with productive cough

Thomas 1978Explicit data from the study were not published and the data are no longer available

 
Comparison 1. Cough at follow-up visit

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of patients with cough4275Risk Ratio (M-H, Fixed, 95% CI)0.64 [0.49, 0.85]

 
Comparison 2. Night cough at follow-up visit

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of patients with night cough4538Risk Ratio (M-H, Fixed, 95% CI)0.67 [0.54, 0.83]

 
Comparison 3. Productive cough at follow-up visit

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of patients with productive cough7713Risk Ratio (M-H, Fixed, 95% CI)0.97 [0.82, 1.16]

    1.1 Acute bronchitis studies
6549Risk Ratio (M-H, Fixed, 95% CI)0.88 [0.72, 1.08]

    1.2 Subgroup with productive cough from URTI study
1164Risk Ratio (M-H, Fixed, 95% CI)1.24 [0.88, 1.75]

 
Comparison 4. Days of cough

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Mean number of days of cough72776Mean Difference (IV, Fixed, 95% CI)-0.46 [-0.87, -0.04]

    1.1 Acute bronchitis studies
62350Mean Difference (IV, Fixed, 95% CI)-0.55 [1.00, -0.10]

    1.2 Subgroup with no placebo control
1426Mean Difference (IV, Fixed, 95% CI)0.11 [-1.01, 1.23]

 
Comparison 5. Days of productive cough

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Mean number of days of productive cough6699Mean Difference (IV, Fixed, 95% CI)-0.43 [-0.93, 0.07]

    1.1 Acute bronchitis studies
5535Mean Difference (IV, Fixed, 95% CI)-0.52 [-1.03, -0.01]

    1.2 Subgroup with productive cough from URTI study
1164Mean Difference (IV, Fixed, 95% CI)1.04 [-1.04, 3.12]

 
Comparison 6. Clinically improved

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of patients reporting no activity limitations or described as cured/globally improved113841Risk Ratio (M-H, Random, 95% CI)1.07 [0.99, 1.15]

 
Comparison 7. Limitation in work or activities at follow-up visit

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of patients with limitations5478Risk Ratio (M-H, Fixed, 95% CI)0.75 [0.46, 1.22]

 
Comparison 8. Days of feeling ill

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Mean number of days of feeling ill5809Mean Difference (IV, Fixed, 95% CI)-0.64 [-1.16, -0.13]

    1.1 Acute bronchitis studies
4435Mean Difference (IV, Fixed, 95% CI)-0.58 [-1.16, -0.00]

    1.2 Subgroup with no placebo control
1374Mean Difference (IV, Fixed, 95% CI)-0.86 [-1.97, 0.25]

 
Comparison 9. Days of impaired activities

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Mean number of days of impaired activities6767Mean Difference (IV, Fixed, 95% CI)-0.49 [-0.94, -0.04]

    1.1 Acute bronchitis studies
5393Mean Difference (IV, Fixed, 95% CI)-0.48 [-0.96, 0.01]

    1.2 Subgroup with no placebo control
1374Mean Difference (IV, Fixed, 95% CI)-0.57 [-1.75, 0.61]

 
Comparison 10. Not improved by physician's global assessment at follow-up visit

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of patients not improved6891Risk Ratio (M-H, Fixed, 95% CI)0.61 [0.48, 0.79]

    1.1 Acute bronchitis studies
5816Risk Ratio (M-H, Fixed, 95% CI)0.44 [0.30, 0.65]

    1.2 Subgroup with non-purulent tracheobronchitis from URTI study
175Risk Ratio (M-H, Fixed, 95% CI)1.03 [0.82, 1.29]

 
Comparison 11. Abnormal lung exam at follow-up visit

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of patients with abnormal lung exams5613Risk Ratio (M-H, Fixed, 95% CI)0.54 [0.41, 0.70]

 
Comparison 12. Adverse effects

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of patients with adverse effects123496Risk Ratio (M-H, Fixed, 95% CI)1.20 [1.05, 1.36]

    1.1 Acute bronchitis studies
113162Risk Ratio (M-H, Fixed, 95% CI)1.22 [1.07, 1.40]

    1.2 Subgroup with no placebo control
1334Risk Ratio (M-H, Fixed, 95% CI)0.95 [0.61, 1.50]