Wenjuanxing-Based Multidimensional Etiologic Screening and Clinical Validation of Chronic Cough in Children

• Development of a Wenjuanxing-based multidimensional etiologic screening questionnaire for pediatric chronic cough This study aims to develop and validate a structured, parent-reported, electronic questionnaire for multidimensional etiologic screening of chronic cough in children, based on current clinical practice guidelines and expert consensus. The questionnaire is designed and deployed on the Wenjuanxing platform and focuses on standardized, comprehensive, and reproducible symptom collection.

The questionnaire includes multiple domains: cough duration and temporal pattern (daytime vs nocturnal cough), cough characteristics (dry vs wet), triggering factors (exercise, cold air, allergen exposure), associated respiratory and extra-respiratory symptoms (wheezing, nasal congestion, postnasal drip, throat clearing, gastroesophageal reflux symptoms), past medical history, family history, and environmental exposures. Logical branching and rule-based algorithms are embedded to automatically generate preliminary etiologic suggestions, including cough variant asthma (CVA), upper airway cough syndrome (UACS), protracted bacterial bronchitis (PBB), post-infectious cough (PIC), eosinophilic bronchitis (EB), and gastroesophageal reflux-related cough (GERC).

The electronic format allows standardized data acquisition, real-time logic checking, automated output of etiologic suggestions, and efficient data export for subsequent clinical evaluation and statistical analysis.

• Clinical validation of the questionnaire in routine outpatient practice This is a prospective, controlled, observational study conducted in the pediatric respiratory outpatient clinic of Shanghai Children's Medical Center. Children aged 3-18 years presenting with cough lasting ≥2 weeks and meeting the inclusion criteria will be consecutively enrolled after informed consent is obtained from their caregivers.

All caregivers will complete the Wenjuanxing questionnaire. Participants will be assigned to one of two parallel groups according to the study protocol: a routine-care group, in which physicians perform diagnosis and treatment based on standard clinical assessment without access to questionnaire results; a questionnaire-assisted group, in which physicians review the questionnaire-generated etiologic suggestions before making diagnostic and therapeutic decisions.

At the initial visit, physicians will record their clinical diagnosis and treatment plan. In the questionnaire-assisted group, physicians will additionally rate the perceived usefulness of the questionnaire and their level of confidence in the questionnaire's etiologic suggestions using standardized numeric scales.

• Follow-up and outcome assessment All enrolled patients will be followed up approximately two weeks after the initial visit via telephone or online contact using a standardized operating procedure. Caregivers will be asked to report changes in cough symptoms, including degree of improvement, time to symptom relief, and overall treatment effectiveness. Caregivers will also rate the perceived consistency between the questionnaire-based etiologic suggestion and the physician's final diagnosis.

If symptom improvement is insufficient, further guidance and an additional follow-up may be conducted according to the study protocol. The primary outcome is the difference in diagnostic accuracy between the routine-care group and the questionnaire-assisted group, with follow-up response serving as post-hoc clinical validation. Secondary outcomes include treatment effectiveness, caregiver satisfaction, physician acceptance, and feasibility of implementing the questionnaire in real-world outpatient settings.

This study aims to establish a scalable, digital, and standardized screening approach for pediatric chronic cough, supporting early etiologic identification and improving clinical decision-making in routine practice.

Inclusion CInclusion Criteria:

• Children aged 3 to 18 years, any sex.
• Presenting for medical care due to cough lasting ≥2 weeks.
• No fever within the past 2 weeks.
• Caregiver is willing to complete the Wenjuanxing questionnaire and agree to follow-up.

Exclusion criteria

• Presence of congenital airway malformations, chronic lung disease, or severe immunodeficiency.
• Recent participation in other interventional clinical research.
• Unable to complete follow-up as required.