Children learning about second-hand smoke (CLASS II)

Children’s exposure to SHS is measured by testing their salivary cotinine levels using a sterile swab. Salivary cotinine concentration is strongly associated with the exposure to SHS at home. Saliva samples will be obtained from all participating children at baseline and also two-months post intervention.

1. Frequency and severity of respiratory symptoms: participating children will be given diaries to record respiratory symptoms on a nominal severity scale from 0 to 3. Children will record their symptoms using facial expressions stickers to show how they feel. These diaries will have three sections. Section 1 will record symptoms from the day intervention is delivered till the end of month-two. Section 2 from the start of month-three till the end of month-six and section 3 from the start of month-seven till the end of month-twelve. At each follow up, one section will be taken out of the diary by the researchers and data will be entered in the database. All children will provide data on section 1. However, only those children will provide data on section 2 and 3 whose cotinine levels are indicative of passive smoking at the baseline. Children will be told whether to stop or keep collecting information in their diaries in a letter. The assessments will be carried out at both baseline and follow ups.
2. Lung Functions: we will measure lung functions on all participating children at the baseline and on children with positive salivary cotinine at month-two, six and twelve. For this we will use a spirometer as per British Thoracic Society guidelines. This would involve measuring forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), peak expiratory flow (PEF), and maximal mean expiratory flow (MMEF). We will first record, height and body weight of all participating children at the baseline. We will enter details of the patient’s sex, race, age and height into the spirometer. We will then ask each child to blow into a disposable mouthpiece attached to the spirometer at least three times as per guidelines. Best of the three readings will be taken. The spirometer will also calculate the percentage of the predicted normal values as they have the reference data already programmed into them. The spirometer will print out a lung function test report for each participant, which will be attached to the participant baseline or follow up questionnaire, respectively. Spirometer will be cleaned according to the manufacturer’s guidelines and its accuracy will be checked regularly. The assessments will be carried out at both baseline and follow ups.
3. Smoking related behaviours: we will ask the children to self-report levels of smoking restrictions and social visibility of smoking at home using a questionnaire. Using the same questionnaire, we will also assess children’s self-reported attitude towards smoking and intention to start smoking. We will use a five-point smoking uptake scale19 to categorise children as non-susceptible non-smokers, susceptible non-smokers, early experimenters, advanced experimenters and established smokers. The assessments will be carried out at both baseline and follow ups.
4. Health service use: we will use a health service utilisation questionnaire previously used in the MCLASS trial, to collect number and type of contacts with doctors, hospital admissions, pharmacy visits and antibiotic prescriptions. This information will be part of the baseline questionnaire but will also be assessed at all follow-up time points.
5. Quality of Life (QoL): QoL (generic) will be assessed by using a short QoL questionnaire for children, PedsQoL. The questions will be included in the baseline and follow up questionnaires.
6. Other confounding variables: at baseline, we will also ask children to report on some of the basic socio-demographic details on the questionnaire. These will include age, gender, household amenities, family structure, co-habiting smokers – including parents, pet ownership, overcrowding - number of rooms and residents, built environment, neighbourhood, presence of mould/moisture in the child’s home, and use of gas for cooking or gas/kerosene/oil heater. Furthermore, we will include information on children’s medical history (particularly asthma and chest infections) and use of any regular medications.
7. Absenteeism and academic performance: each participating school will be asked to provide a report on the academic performance of participating children using the Academic Performance Questionnaire (APQ), a 10-item questionnaire to be completed by teachers. Using 4- and 5-point ordinal scales, it measures child’s performance in reading, mathematics, writing, and homework. This questionnaire will be completed at the baseline and at all follow-ups. In addition, schools will also be requested to provide a record of child’s absenteeism from school including number of days missed every month in between two assessments.
8. Fidelity Index: the research team will use a fidelity index, mapped onto the behaviour change techniques that underpin SFI, to assess intervention adherence. This will be in the form of a check list, which will used to monitor the delivery of SFI sessions. One of the members of the research team will attend all SFI sessions and using the above check list will score fidelity to SFI.