Table 1.
Baseline parameter values informed by the literature and the survey among heterosexual males and females aged 16–26 years. SB, sexual behaviour; RP, risk perception.
| parameters | baseline values | |||
|---|---|---|---|---|
| infection parameters (informed by literature) | value | source | ||
| chlamydia prevalence (%) | 4 | [27,39] | ||
| transmission probability (per sex act)a | 0.07 | |||
| duration of infection (years) | 1 | [41,42] | ||
| behavioural parameters (informed by the survey)b | ||||
| SB model and SB–RP model | low-risk sexual behaviour (n = 120) | high-risk sexual behaviour (n = 53) | ||
| number of partners, per year (median) | 1 | 4 | ||
| percentage of population in a partnership (%) | 73.7 | 69.2 | ||
| SB model only | ||||
| percentage of group in total population (%) | 70 | 30 | ||
| number of sex acts, past four weeks (median) | 6 | 4 | ||
| condom use most recent sex act (%) | 27.2 | 39.6 | ||
| SB–RP model only | pessimist (n = 32) | low-risk realist (n = 88) | high-risk realist (n = 35) | optimist (n = 18) |
| percentage of group in total population (%) | 18.9 | 51.1 | 19.8 | 10.2 |
| number of sex acts, past four weeks (median) | 6 | 7 | 3 | 5.3 |
| condom use most recent sex act (%) | 24.1 | 28.2 | 37.1 | 44.4 |
aCalibrated to the steady-state prevalence.
bCalculated using behavioural data from the survey (see electronic supplementary material, S1.3).