Additional file 1: of The impact of cycle proficiency training on cycle-related behaviours and accidents in adolescence: findings from ALSPAC, a UK longitudinal cohort

Supplementary Tables (Tables A, B, and C). (DOCX 15 kb

Recent UK population based studies of prevalence of chlamydia in the general population.

a<p>Natsal and ClaSS estimates weighted by sampling probabilities, Natsal 2010 additionally weighted for test refusal. ALSPAC adjusted prevalence estimates based on multiply-imputed data.</p

Measures of socioeconomic and educational disadvantage, comparing i) participants who did and did not attend the research clinic and ii) clinic attendees who did and did not take the chlamydia test.

a<p>Percentages using all observed values for each variable.</p>b<p>Special Educational Needs (SEN) status at one or more timepoint (age 7, 12–13 and/or 13–14 years).</p

Adjusted associations between chlamydia infection and gender, socioeconomic position, education and number of sexual partners, with complete case analysis and using three sensitivity tests examining missing data.

a<p>N varies between 1809 and 2879 due to missing values of measures of socioeconomic position and number of sexual partners.</p>b<p>Model 1: Adjusted for age and other measures of socio-economic position that were considered to be potential confounders, identified using a hierarchical conceptual framework.</p>c<p>Model 2: Adjusted for variables in Model 1 and reported number of sexual partners.</p

Unadjusted associations between chlamydia infection and gender, socioeconomic position, education and number of sexual partners.

a<p>Unadjusted analyses using all available data. 2879 participants have valid results from chlamydia tests at the clinic. Counts for some covariables add up to less than 2879 due to missing values of exposures.</p

Estimates of prevalence of chlamydia Infection i) for all participants and ii) those reporting sexual activity, by gender, with and without sensitivity test for bias due to missing data.

<p>Notes: ^aData were multiply imputed for the 9568 participants who attended the study clinic.</p>b<p>The number of cases of chlamydia among participants reporting sexual activity is 16, rather than 20, because four participants who tested positive for chlamydia did not respond to the question on sexual activity.</p

Descriptives of confounders by frequency of cigarette use at age 16% (N).

<p>¹No higher education. Categorised like this for purposes of presentation in this table only.</p><p>²Defined as score of 4 or over, for the purposes of presentation in this table only.</p><p>³Early onset persistent group membership. Categorised like this for purposes of presentation in this table only.</p><p>⁴Ever used cannabis. Categorised like this for purposes of presentation in this table only.</p><p>⁵Hazardous alcohol use. Categorised like this for purposes of presentation in this table only.</p><p>Descriptives of confounders by frequency of cigarette use at age 16% (N).</p

Descriptives of confounders by cumulative cannabis use at age 16% (N).

<p>FH- family history; IQ- intelligence quotient.</p><p>¹No higher education. Categorised like this for purposes of presentation in this table only.</p><p>²Defined as score of 4 or over, for the purposes of presentation in this table only.</p><p>³Early onset persistent group membership. Categorised like this for purposes of presentation in this table only.</p><p>⁴Weekly or daily smoking. Categorised like this for purposes of presentation in this table only.</p><p>⁵Hazardous alcohol use. Categorised like this for purposes of presentation in this table only.</p><p>Descriptives of confounders by cumulative cannabis use at age 16% (N).</p

Study Participant Flow Diagram.

<p>Study Participant Flow Diagram.</p

Correlations between parental alcohol measures (linear term) at age 4 and 12 years.

<p>Correlations between parental alcohol measures (linear term) at age 4 and 12 years.</p