Risk Factors for Recurrent Respiratory Tract Infections in Preschool Children: A Meta-Analysis.

Area of Science:

• Pediatric Infectious Diseases
• Epidemiology
• Public Health

Background:

• Recurrent respiratory tract infections (RRTI) pose a significant health burden on preschool children globally.
• Identifying modifiable risk factors is crucial for developing effective prevention strategies.

Purpose of the Study:

• To systematically review and meta-analyze observational studies on risk factors for RRTI in preschool children.
• To evaluate the effect sizes of major risk factors associated with RRTI.

Main Methods:

• A comprehensive literature search was conducted across multiple databases (PubMed, Embase, CNKI, etc.) up to September 2025.
• Observational studies focusing on preschool children and RRTI outcomes were included.
• Key indicators analyzed included household economic status, maternal age, breastfeeding duration, snack intake, passive smoking, asthma, and vitamin A deficiency.

Main Results:

• Meta-analysis identified asthma (OR=3.26), passive smoking (OR=1.50), and frequent snack intake (OR=1.61) as significant risk factors for RRTI.
• Older maternal age showed a protective association (OR=0.941).
• No significant associations were found for household economic status, breastfeeding duration (<6 months), or vitamin A deficiency.

Conclusions:

• Asthma, passive smoking, and frequent snacking are confirmed risk factors for RRTI in preschool children.
• Older maternal age may be protective.
• Prevention efforts should focus on asthma management, smoking cessation, and promoting healthy dietary habits.