Can Acute Cough Characteristics From Sound Recordings Differentiate Common Respiratory Illnesses in Children?: A Comparative Prospective Study

BACKGROUND

Acute respiratory illnesses cause substantial morbidity worldwide. Cough is a common symptom in these childhood respiratory illnesses, but no large cohort data are available on whether various cough characteristics can differentiate between these etiologies.

RESEARCH QUESTION

Can various clinically based cough characteristics (frequency [daytime/ nighttime], the sound itself, or type [wet/dry]) be used to differentiate common etiologies (asthma, bronchiolitis, pneumonia, other acute respiratory infections) of acute cough in children?

STUDY DESIGN AND METHODS

Between 2017 and 2019, children aged 2 weeks to ≤16 years, hospitalized with asthma, bronchiolitis, pneumonia, other acute respiratory infections, or control subjects were enrolled. Spontaneous coughs were digitally recorded over 24 hours except for the control subjects, who provided three voluntary coughs. Coughs were extracted and frequency defined (coughs/hour). Cough sounds and type were assessed independently by two observers blinded to the clinical data. Cough scored by a respiratory specialist was compared with discharge diagnosis using agreement (Cohen's kappa coefficient [қ]), sensitivity, and specificity. Caregiver-reported cough scores were related with objective cough frequency using Spearman coefficient (r_s).

RESULTS

A cohort of 148 children (n = 118 with respiratory illnesses, n = 30 control subjects), median age = 2.0 years (interquartile range, 0.7-3.9), 58% males, and 50% First Nations children were enrolled. In those with respiratory illnesses, caregiver-reported cough scores and wet cough (range, 42%-63%) was similar. Overall agreement in diagnosis between the respiratory specialist and discharge diagnosis was slight (қ = 0.13; 95% CI, 0.03 to 0.22). Among diagnoses, specificity (8%-74%) and sensitivity (53%-100%) varied. Interrater agreement in cough type (wet/dry) between blinded observers was almost perfect (қ = 0.89; 95% CI, 0.81 to 0.97). Objective cough frequency was significantly correlated with reported cough scores using visual analog scale (r_s = 0.43; bias-corrected 95% CI, 0.25 to 0.56) and verbal categorical description daytime score (r_s = 0.39; bias-corrected 95% CI, 0.22 to 0.54).

INTERPRETATION

Cough characteristics alone are not distinct enough to accurately differentiate between common acute respiratory illnesses in children.

Antibiotics for persistent cough or wheeze following acute bronchiolitis in children

BACKGROUND

Bronchiolitis is a common acute respiratory condition with high prevalence worldwide. This clinically diagnosed syndrome is manifested by tachypnoea (rapid breathing), with crackles or wheeze in young children. In the acute phase of bronchiolitis (≤ 14 days), antibiotics are not routinely prescribed unless the illness is severe or a secondary bacterial infection is suspected. Although bronchiolitis is usually self-limiting, some young children continue to have protracted symptoms (e.g. cough and wheezing) beyond the acute phase and often re-present to secondary care.

OBJECTIVES

To compare the effectiveness of antibiotics versus controls (placebo or no treatment) for reducing or treating persistent respiratory symptoms following acute bronchiolitis within six months of acute illness.

SEARCH METHODS

We searched the following databases: the Cochrane Airways Group Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid), the World Health Organization (WHO) trial portal, the Australian and New Zealand Clinical Trials Registry, and ClinicalTrials.gov, up to 26 August 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing antibiotics versus controls (placebo or no treatment) given in the post-acute phase of bronchiolitis (> 14 days) for children younger than two years with a diagnosis of bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies against predefined criteria, and selected, extracted, and assessed data for inclusion. We contacted trial authors for further information.

MAIN RESULTS

In this review update, we added one study with 219 children. A total of two RCTs with 249 children (n = 240 completed) were eligible for inclusion in this review. Both studies contributed to our primary and secondary outcomes, but we assessed the quality of evidence for our three primary outcomes as low, owing to the small numbers of studies and participants; and high attrition in one of the studies. Data show no significant differences between treatment groups for our primary outcomes: proportion of children (n = 249) who had persistent symptoms at follow-up (odds ratio (OR) 0.69, 95% confidence interval (CI) 0.37 to 1.28; fixed-effect model); and number of children (n = 240) rehospitalised with respiratory illness within six months (OR 0.54, 95% CI 0.05 to 6.21; random-effects model). We were unable to analyse exacerbation rate because studies used different methods to report this information. Data showed no significant differences between treatment groups for our secondary outcome: proportion of children (n = 240) with wheeze at six months (OR 0.47, 95% CI 0.06 to 3.95; random-effects model). One study reported bacterial resistance, but only at 48 hours (thus with limited applicability for this review). Another study reported adverse events from which all children recovered and remained in the study.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to inform whether antibiotics should be used to treat or prevent persistent respiratory symptoms in the post-acute bronchiolitis phase. Future RCTs are needed to evaluate the efficacy of antibiotics for reducing persistent respiratory symptoms. This is particularly important in populations with high acute and post-acute bronchiolitis morbidity (e.g. indigenous populations in Australia, New Zealand, and the USA).