Association of different risk factors with wheeze ever in white children aged one year (unadjusted).

<p>ETS: environmental tobacco smoke</p><p>*Attack group: "Did she smoke in the year this child was born?"; Whistling group: "Did she smoke during the pregnancy with this child?"</p><p>^† The categories cover the following Townsend Deprivation Index intervals: more affluent: [-6.222, -1.397]; average: [-1.396, 2.828]; more deprived: [2.829, 11.072]; We used a likelihood-ratio test to calculate the p-value for interaction for this variable</p><p>^‡ Age at end of education >16 years (mother or father)</p><p>Association of different risk factors with wheeze ever in white children aged one year (unadjusted).</p

Prevalence of indicators of wheeze severity (white children).

<p>^† Chi squared tests</p><p>Prevalence of indicators of wheeze severity (white children).</p

Crude and adjusted odds ratios for respiratory symptoms in white children.

<p>The odds ratios compare the whistling group to the attack group (adjusted for sex, exact age, breast feeding, nursery care, number of siblings, pre- and postnatal exposure to environmental tobacco smoke (ETS), parental asthma and parental hay fever, Townsend score (an area-based deprivation measure) and parental education). The error bars denote 95% confidence intervals.</p

Kappa values and their interpretation for intra-rater and inter-rater reliability.

<p>Fig 2 shows the values of kappa for intra-rater (dark blue) and for inter-rater (light blue) reliability with their confidence intervals T for each variable under investigation.</p

Flow chart of sample selection for reliability assessment.

<p>Fig 1 shows the flow chart of our study population starting from those eligible to those included in the analysis.</p

Inter-rater reliability.

<p>Abbreviations: CI, Confidence Interval; kappa, Cohen’s kappa; n.a., not applicable; PABAK, Prevalence and Bias Adjusted Kappa.</p><p>Inter-rater reliability.</p

Kappa values and Prevalence-adjusted Bias-adjusted kappa values for intra-rater (a) and inter-rater reliability (b).

<p>Fig 3a and 3b show the values of kappa compared to the the values obtained by calculating the Prevalence-adjusted Bias-adjusted kappa for intra-rater reliability (a) and inter-rater reliability (b).</p

Prevalence of wheeze and other respiratory symptoms (white children).

<p>*A few questionnaire items had different wording in the two groups. Among them was the question about wheeze ever: Attack group: "Has your child ever had attacks of wheezing?"; Whistling group: "Has your child ever had wheezing or whistling in the chest at any time in the past?" Based on this, the groups were labeled "attack group" and "whistling group".</p><p>^† Chi squared tests</p><p>Prevalence of wheeze and other respiratory symptoms (white children).</p

Intra-rater reliability.

<p>Abbreviations: CI, Confidence Interval; kappa, Cohen’s kappa; n.a., not applicable; PABAK, Prevalence and Bias Adjusted Kappa.</p><p>Intra-rater reliability.</p

Variables assessed in the re-abstraction.

<p>The categorical variables represent a more challenging collection than date variables because the corresponding information had to be found in free text and often necessitated an interpretation.</p><p>Variables assessed in the re-abstraction.</p