Table 1

 Baseline parameter values used in mathematical model

Adapted from Turner et al.14
*Parameters drawn from a negative binomial distribution, mean, and dispersion.
Behavioural parameters
Preferred number of concurrent partners1 or 2
Proportion wanting 2 partners (<35 years old)0.05Assumption based on Kretzschmar model12
Initial proportion of 16 year olds desiring short partnershipsFitted to Natsal 200014,18
Proportion who switch from desiring short to long partnerships per yearFitted to Natsal 200014,18
Mean duration of short partnerships (in days)14Assumption
Mean duration of long partnerships for 16 year olds (in days) 900Fitted to Natsal 200014,18
Increase in duration (in days) per year200Fitted to Natsal 200014,18
Mean gap between partnerships (in days), (dispersion)*14 (2)Assumption
Number of sex acts per dayAssumption based on Kretzschmar model12
    Short partnerships1
    Long partnerships0.25
Infection parameters
Transmission probability per sex act0.0375Fitted to Natsal 200017 and Adams et al4
Duration, no treatment seeking (in days)180Assumption
Duration, treatment seeking (in days)30Assumption
Proportion seeking treatmentFitted to Natsal 200017 and Adams et al4
Mean refractory period following treatment (in days), (dispersion)*7 (10)Assumption based on CEG guidelines21
Healthcare parameters (baseline)
Annual attendance rate at health care setting (proportion who report attending a healthcare setting in the last 12 months)0.85Chlamydia Recall Study20
Probability of accepting screen0.5Assumption based on screening studies19,22
Proportion of partners notified0.2Fitted to Natsal 200017 and Adams et al4
Treatment efficacy (in those partner notified or screened)0.95Treatment guidelines23
Mean delay (in days) before partner treatment (dispersion)*7 (10)Assumption based on Recall Study (unpublished)