A pragmatic assessment of the relative efficiency of outreach chlamydia screening events conducted in non-clinical settings

Background: Opportunistic screening for chlamydia in non-clinical settings is becoming more common, but little is known about which settings (or events) offer the best return on investment. We measured the relative efficiency of each screening site and event during the conduct of a chlamydia education and screening outreach program which used a cash incentive to encourage participation (SOC2). Methods. SOC2 staff identified sites and organised events in non-clinical sites where young people were likely to congregate. 16 to 30years olds were offered chlamydia education and a cash reward of AUD10 if they chose to be screened for chlamydia. Data collected during these activities were used to calculated five measures of efficiency: i) screening yield' (proportion of people providing a sample), ii) proportion of positive tests, iii) 'event screening tempo' (number of screens performed for every hour that screening is offered), iv) 'staff hour screening tempo' (number of screens performed per hour of staff time) and v) 'chlamydia detection tempo' (number of positive tests detected per hour of screening). Results: 3011 people (71% male) were screened during 18 events at 10 venues. Overall 'screening yield' was 43.8% (range: 20-77%) and 1.7% (95% CI: 1.1-3.0) of tests were positive (by event range 1-3%). Overall, the 'event screening tempo' was 23.7 screens per event hour (range 8.0-79.0), the 'staff hour screening tempo' was 6.5 screens per staff hour and the chlamydia detection tempo was 0.4 positive tests per hour (range: 0-1.75). Conclusion: Assessing the efficiency of screening sites and programs should be integral to their conduct. We suggest the use of five measures to enable pragmatic assessment of any screening program. We introduce the terms 'event screening tempo', 'staff hour screening tempo' and 'chlamydia detection tempo' to describe three of these simple measures.