Children aged from 1 month to 18 years of age diagnosed with complicated community
acquired pneumonia (pneumonia with parapneumonic effusion, necrotizing pneumonia or lung
abscess) who were admitted from January 1st 2014 to April 30th 2024 to participating
centers will be considered eligible for this multi-centric retrospective study.
The medical charts of all selected patients will be reviewed by medical professionals at
each center and data collected in a standardized electronic database specifically created
for this study to ensure consistency. Data quality will be internally monitored by the
lead investigator, with periodic data validation checks to identify and resolve
inconsistencies. All patient information will be stored securely in accordance with local
regulations.
For every enrolled patient the following variables will be obtained: age, gender, date of
admission, onset of symptoms and antibiotic treatment prior to hospitalization,
comorbidities, immunization status, vital parameters on admission (heart rate,
respiratory rate and percutaneous blood oxygen saturation), laboratory tests results on
admission (white blood cells count, C-reactive protein concentration, blood gases, serum
albumin concentration, serum lactate dehydrogenase activity), biochemical and cytological
characteristics of pleural effusion (if applicable), microbiological results (culture and
polymerase chain reaction) with Streptococcus pneumoniae serotype and its antimicrobial
susceptibility to antibiotics, imaging (chest X-ray, CT scan, lung ultrasound), flexible
bronchoscopy findings (if applicable), treatment modalities encompassing length of
antibiotic therapy, use of systemic steroids, thoracic drainage, application of
intrapleural fibrinolytics and surgical treatment, respiratory support information,
length of hospitalization and intensive care unit stay, complications, chest radiography
at follow up (at 3, 6, 12 months after discharge is available) and information on
fatal/nonfatal outcome.
Primary outcome The primary outcome of this study is to estimate incidence and provide
information on clinical characteristics of complicated community acquired pneumonia,
particularly necrotizing pneumonia, in children and also identify possible association
between microbiological isolates, immunization status and severity of clinical course.
Secondary outcomes
Comparison of pre- and post- pneumococcal conjugate vaccine period (in selected
countries) regarding the number of cases, isolated Streptococcus pneumoniae and
antimicrobial resistance
Determining if high values of inflammatory markers in serum can be predictive
factors for complicated clinical course
Evaluation of the effectiveness of the early introduction of intrapleural
fibrinolytic therapy to length of hospital stay and incidence of complications
(including bronchopleural fistula).
Use the systemic corticosteroids for empyema and associated necrotizing pneumonia
and the risk for bronchopleural fistula
Evaluation of frequent use of antibiotics and higher prevalence of multi-drug
resistant Streptococcus pneumoniae.
Determination of risk factors for surgical therapy
The primary outcome, incidence of complicated community acquired pneumonia, will be
compared between vaccinated and non-vaccinated groups using chi-square tests for
categorical variables and t-tests for continuous variables. Secondary outcomes, such as
length of hospital stay and complications, will be analyzed using ANOVA and logistic
regression, adjusting for potential confounders such as age and comorbidities. Subgroup
analyses will assess differences in outcomes across age groups and different vaccination
periods (pre- and post- 13 valent pneumococcal conjugate vaccine). Statistical
significance will be defined as p<0.05. Statistical analyses will be performed using
SPSS, version 26.