Differences upon admission and in hospital course of children hospitalized with community-acquired pneumonia with or without radiologically-confirmed pneumonia: a retrospective cohort study

BACKGROUND: The use of chest radiograph (CXR) for the diagnosis of childhood community-acquired pneumonia (CAP) is controversial. We assessed if children with CAP diagnosed on clinical grounds, with or without radiologically-confirmed pneumonia on admission, evolved differently. METHODS: Children aged ≥ 2 months, hospitalized with CAP diagnosed on clinical grounds, treated with 200,000 IU/Kg/day of aqueous penicillin G for ≥ 48 h and with CXR taken upon admission, without pleural effusion, were included in this retrospective cohort. One researcher, blinded to the radiological diagnosis, collected data on demographics, clinical history and physical examination on admission, daily hospital course during the first 2 days of treatment, and outcome, all from medical charts. Radiological confirmation of pneumonia was based on presence of pulmonary infiltrate detected by a paediatric radiologist who was also blinded to clinical data. Variables were initially compared by bivariate analysis. Multi-variable logistic regression analysis assessed independent association between radiologically-confirmed pneumonia and factors which significantly differed during hospital course in the bivariate analysis. The multi-variable analysis was performed in a model adjusted for age and for the same factor present upon admission. RESULTS: 109 (38.5 %) children had radiologically-confirmed pneumonia, 143 (50.5 %) had normal CXR and 31 (11.0 %) had atelectasis or peribronchial thickening. Children without radiologically-confirmed pneumonia were younger than those with radiologically-confirmed pneumonia (median [IQR]: 14 [7–28 months versus 21 [12–44] months; P = 0.001). None died. The subgroup with radiologically-confirmed pneumonia presented fever on D1 (33.7 vs. 19.1; P = 0.015) and on D2 (31.6 % vs. 16.2 %; P = 0.004) more frequently. The subgroup without radiologically-confirmed pneumonia had chest indrawing on D1 (22.4 % vs. 11.9 %; P = 0.027) more often detected. By multi-variable analysis, Fever on D2 (OR [95 % CI]: 2.16 [1.15-4.06]) was directly and independently associated with radiologically-confirmed pneumonia upon admission. CONCLUSION: The compared subgroups evolved differently.