Chlamydia screening studies: summary of planned sample sizes
| Component | Planned study size |
|---|---|
| See www.chlamydia.ac.uk for study protocols with detailed sample size calculations. | |
| Prevalence study | Age stratified random sample of 10 000 women and men aged 16–39 years |
| Case-control study | 170 women with chlamydia infection (cases) and 340 women testing negative (controls); 114 and 228 male cases and controls |
| Partner notification trial | 100 index cases with chlamydia infection in each study arm |
| Laboratory evaluation of tests and specimens | See table A1.2 |
| Studies of psychological, emotional and social effects | Up to 80 in-depth interviews with purposively selected informants who received positive and negative test results, informants randomised to each arm of the partner notification trial, informants who declined participation, practice nurses, general practitioners and health advisers involved in ClaSS |
| Anxiety surveys at three time points in age stratified random sample of 1000 women and men (before study pack was sent out, after receiving study pack; after receiving negative result). | |
| Economic evaluation | A simulated modeled population to evaluate the cost effectiveness of screening based on major outcome averted |