Comparison of lower airway sampling strategies in children with protracted bacterial bronchitis

A multi-centre, prospective, cross-sectional cohort study comparing the microbiology yields of cough swab and induced sputum samples with that of bronchoalveolar lavage samples obtained during flexible bronchoscopy, in children with protracted bacterial bronchitis

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN79883982

Enrollment

131

Registered

2021-11-08

Start date

2021-10-29

Completion date

Unknown

Last updated

2026-07-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Protracted bacterial bronchitis Respiratory

Interventions

Participants will have two extra samples taken (a cough swab and an induced sputum sample) when they attend the hospital for their bronchoscopy. The study does not need any extra hospital visits and d

Eligibility

Sex/Gender

All

Age

1 Years to 10 Years

Inclusion criteria

Inclusion criteria: 1. Aged 1-10 years 2. Have a clinical diagnosis of PBB 3. Referred for a clinically indicated FB-BAL 4. Parent/guardian willing and able to give fully informed consent 5. Willing and able to comply with the study procedures

Exclusion criteria

Exclusion criteria: 1. Diagnosis of bronchiectasis, cystic fibrosis or immunodeficiency 2. FB-BAL being performed for a therapeutic indication (i.e. lobar collapse) rather than for lower airway 3. Currently taking part in another interventional study 4. Non-English speaker where translation facilities are insufficient to guarantee informed consent

Design outcomes

Primary

Measure	Time frame
1. Discordance of pathogen yield between induced sputum and FB-BAL approximately 48-72 hours post-procedure. If the same organisms are not identified in both samples the pathogen yield is discordant. Discordance will be classified as CS+/FB-BAL- when an organism is isolated on cough swab but not on FB-BAL or CS-/FB-BAL+ when an organism is isolated on the FB-BAL but not on the cough swab. 2. Discordance of pathogen yield between cough swab and FB-BAL approximately 48-72 hours post-procedure. If the same organisms are not identified in both samples the pathogen yield is discordant. Discordance will be classified as IS+/FB-BAL- when an organism is isolated on induced sputum but not on FB-BAL or IS-/FB-BAL+ when an organism is isolated on FB-BAL but not on induced sputum.	—

Measure

Time frame

1. Discordance of pathogen yield between induced sputum and FB-BAL approximately 48-72 hours post-procedure. If the same organisms are not identified in both samples the pathogen yield is discordant. Discordance will be classified as CS+/FB-BAL- when an organism is isolated on cough swab but not on FB-BAL or CS-/FB-BAL+ when an organism is isolated on the FB-BAL but not on the cough swab. 2. Discordance of pathogen yield between cough swab and FB-BAL approximately 48-72 hours post-procedure. If the same organisms are not identified in both samples the pathogen yield is discordant. Discordance will be classified as IS+/FB-BAL- when an organism is isolated on induced sputum but not on FB-BAL or IS-/FB-BAL+ when an organism is isolated on FB-BAL but not on induced sputum.

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Secondary

Measure	Time frame
1. The sensitivity of each sampling technique calculated from triplicate (CS/is/BAL) culture results approximately 48-72 hours post-procedure. 2. Success of sputum induction collected via the case report form (CRF) on the day of sample collection 3. Tolerability of sampling techniques using Tolerability Questionnaire on the day of sample collection	—

Countries

England, United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Jul 23, 2026