Prevalence of Pneumonia among Children Aged ۴–۱۱ Years Diagnosed with Nephrotic Syndrome and Hospitalized in Educational Therapeutic Hospitals in Urmia, Iran: A Retrospective Record-Based Study

Background: Children with nephrotic syndrome (NS) face increased infection risk due to immune dysregulation and immunosuppressive therapy. Pneumonia is a major cause of morbidity, but region-specific data from Iran are limited. This study aimed to determine the prevalence of pneumonia and its associated factors among hospitalized children with NS in Urmia, Iran.Methods: A retrospective record-based study was conducted at educational therapeutic hospitals in Urmia, including children aged ۴–۱۱ years with confirmed NS hospitalized between January ۱, ۲۰۲۰, and December ۳۱, ۲۰۲۴. Pneumonia was defined using standardized World Health Organization (WHO) chest radiograph criteria, including the presence of new infiltrates, consolidation, or pleural effusion, accompanied by clinical features such as fever (≥۳۸.۰°C), tachypnea, cough, and/or oxygen desaturation. Multivariable logistic regression was used to identify factors independently associated with pneumonia.Results: Among ۲۰۶ children included in the study (median age ۷.۲ years; ۵۷.۳% male), the overall prevalence of radiologically confirmed pneumonia was ۲۰.۴% (۹۵% CI: ۱۵.۱–۲۶.۶%). Community-acquired pneumonia accounted for ۷۳.۸% of cases, while nosocomial pneumonia accounted for ۲۶.۲%. The prevalence was significantly higher in children aged ۴–۷ years compared to those aged ۸–۱۱ years (۲۶.۸% vs. ۱۲.۸%, p=۰.۰۱۲) and in steroid-resistant versus steroid-sensitive NS (۳۴.۰% vs. ۱۶.۰%, p = ۰.۰۰۶). In multivariable analysis, after adjusting for age, sex, relapse frequency, immunosuppressive therapy, vaccination status, length of hospital stay, history of previous lower respiratory tract infection (LRTI), and seasonality, younger age (aOR per ۱-year increase: ۰.۷۶; ۹۵% CI: ۰.۶۳–۰.۹۳; p=۰.۰۰۶) and higher relapse frequency (aOR per additional relapse: ۱.۴۲; ۹۵% CI: ۱.۱۲–۱.۸۱; p=۰.۰۰۴) remained independently associated with pneumonia. Documented pneumococcal and influenza vaccination rates were low (۲۹.۶% and ۲۳.۳%, respectively) and likely represent minimum estimates due to incomplete record-keeping.Conclusions: Pneumonia affects one in five hospitalized children with NS in Urmia. Younger age and frequent relapses are independently associated with pneumonia in this population. Suboptimal documented vaccination coverage represents a potentially modifiable target for prevention; however, improved record-keeping is necessary to confirm true coverage rates. Clinicians should maintain a low threshold for diagnosing pneumonia and prioritize vaccination review at every healthcare encounter.

کلیدواژه ها:

Community-acquired pneumonia ، incidence ، Nephrotic syndrome ، pediatric pneumonia