Indigenous children or children with new abnormal auscultatory findings were significantly more likely than children in other categories to respond to oral antibiotics for exacerbations related to bronchiectasis, based on data from more than 200 individuals in New Zealand.
Children and adolescents with bronchiectasis are often treated with antibiotics for respiratory exacerbations, but the effects of antibiotics can vary among individuals, and phenotypic features associated with greater symptom resolution have not been identified, wrote Vikas Goyal, PhD, of the Centre for Children’s Health Research, Brisbane, Australia, and colleagues.
Previous studies have suggested that nearly half of exacerbations in children and adolescents resolve spontaneously after 14 days, and more data are needed to identify which patients are mostly likely to benefit from antibiotics, they noted.
In a study published in the journal Chest, the researchers reviewed secondary data from 217 children and adolescents aged 1-18 years with bronchiectasis enrolled in a pair of randomized, controlled trials comparing oral antibiotics with placebo (known as BEST-1 and BEST-2). The median age of the participants was 6.6 years, 52% were boys, and 41% were Indigenous (defined as Australian First Nations, New Zealand Maori, or Pacific Islander). All participants in the analysis received at least 14 days of oral antibiotics for treatment of nonhospitalized respiratory exacerbations.
Overall, 130 children had resolution of symptoms by day 14, and 87 were nonresponders.
In a multivariate analysis, children who were Indigenous or who had new abnormal auscultatory findings were significantly more likely to respond than children in other categories (odds ratios, 3.59 and 3.85, respectively).
Patients with multiple bronchiectatic lobes at the time of diagnosis and those with higher cough scores at the start of treatment were significantly less likely to respond to antibiotics than patients without these features (OR, 0.66 and 0.55, respectively).
The researchers conducted a further analysis to examine the association between Indigenous ethnicity and treatment response. They found no differences in the other response variables of number of affected lobes at diagnosis and cough scores at the start of treatment between Indigenous and non-Indigenous children.
Given the strong response to antibiotics among Indigenous children, the researchers also conducted a mediation analysis. “Respiratory bacterial pathogens were mediated by Indigenous ethnicity and associated with being an antibiotic ‘responder,’ ” they wrote. For new abnormal chest auscultatory findings, both direct and indirect effects on day 14 response to oral antibiotics were mediated by Indigenous ethnicity. However, neither cough scores at the start of treatment nor the number of affected lobes at diagnosis showed a mediation effect from Indigenous ethnicity.
Among the nonresponders, 59 of 87 resolved symptoms with continuing oral antibiotics over the next 2-4 weeks, and 21 improved without antibiotics.
Additionally, the detection of a respiratory virus at the start of an exacerbation was not associated with antibiotic failure at 14 days, the researchers noted.
The findings were limited by several factors including the use of data from randomized trials that were not designed to address the question in the current study, the researchers noted. Other limitations included incomplete clinical data and lack of data on inflammatory indices, potential antibiotic-resistant pathogens in nonresponders, and the follow-up period of only 14 days, they said.
However, the results suggest a role for patient and exacerbation phenotypes in management of bronchiectasis in clinical practice and promoting antimicrobial stewardship, the researchers wrote. “Although there is benefit in treating exacerbations early to avoid treatment failure and subsequent intravenous antibiotics, future research also needs to identify exacerbations that can be managed without antibiotics,” they concluded.
The BEST-1 and BEST-2 studies were supported by the Australian National Health and Medical Research Council and the NHMRC Centre for Research Excellence in Lung Health of Aboriginal and Torres Strait Islander Children. Dr. Goyal had no financial conflicts to disclose.