INTRODUCTION

Lung function assessment of preschool children is hindered by their limited co-operation in conventional tests such as peak expiratory flow (PEF) or spirometry and the methods available for younger children are, again, laborious and time consuming. However, impedance pneumography (IP) records indices of airway obstruction during normal sleep at home and has been shown accurate in wheezy preschool children (Seppä et al. J Appl Physiol 2013).

AIM OF THE STUDY

The general purpose of this study is to assess the clinical value of the information provided by overnight home recording of tidal breathing by means of IP technique in young children with asthmatic symptoms and inhaled corticosteroid (ICS) medication.

The main hypothesis is that IP measurement can distinguish between groups whose asthmatic symptoms recur or do not recur after ending the ICS drug treatment period.

METHODS

The study recruits 1-5 year old children (n=75) who have presented at the emergency room due to obstructive bronchitis and for whom an ICS drug treatment period has been prescribed based on the national guidelines.

The subjects will perform three overnight IP measurements at home at two weeks intervals close to and after ending of the treatment period.

SIGNIFICANCE OF THE STUDY

Being an affordable, simple and convenient ambulatory measurement method, IP may bring needed objectivity to asthma diagnostics and asthma drug response assessment in young children.

QUALITY CONTROL AND QUALITY ASSURANCE

Information of study personnel and training All personnel involved with the use of the IP measurement device will be instructed by Ville-Pekka Seppä.

Protocol amendments Essential amendments in the research protocol will be reviewed by the institutional review board and informed to National Supervisory Authority of Welfare and Health (Valvira).

DATA HANDLING AND RECORD KEEPING Electronic data collection Electronic data will consist of IP recorder device data files (.ipr). Upon complete protocol execution there will be three files for each patient. These files will be stored in a computer in TAYS Allergiakeskus.

Data management Access to all collected patient information and the patient information collected before the study in the primary care centers will be accessible to RN Tiina Mäki (0503439195), MD Marita Paassilta, and MD Jussi Karjalainen of Allergiakeskus.

Research group members from TUT will have access only to data that does not enable identifying individual patients and where individual patients are referred to by participant codes.

Study subject register The study subject register will be treated per the Finnish Personal Data Act article 10.

Inclusion Criteria:

• Age 1-5 yrs
• Recurrent obstructive bronchitis
• Inhaled corticosteroid treatment has been prescribed

Exclusion Criteria:

• Laryngeal disease
• Tracheobronchial malacia
• Parenchymal lung disease
• History of bronchopulmonary dysplasia
• Active implantable medical such as pacemakers

1-5 year old patients who have visited the TAYS emergency room due to obstructive bronchitis and have been instructed to begin a three-month period of inhaled corticosteroid (ICS) treatment as per national guidelines.