Modelling the impact of opportunistic screening on the sequelae and public healthcare costs of infection with Chlamydia trachomatis in Australian women

Chlamydia sequelae cost estimates used in current economic evaluations: does one-size-fit-all?

BACKGROUND

Current evidence suggests that chlamydia screening programmes can be cost-effective, conditional on assumptions within mathematical models. We explored differences in cost estimates used in published economic evaluations of chlamydia screening from seven countries (four papers each from UK and the Netherlands, two each from Sweden and Australia, and one each from Ireland, Canada and Denmark).

METHODS

From these studies, we extracted management cost estimates for seven major chlamydia sequelae. In order to compare the influence of different sequelae considered in each paper and their corresponding management costs on the total cost per case of untreated chlamydia, we applied reported unit sequelae management costs considered in each paper to a set of untreated infection to sequela progression probabilities. All costs were adjusted to 2013/2014 Great British Pound (GBP) values.

RESULTS

Sequelae management costs ranged from £171 to £3635 (pelvic inflammatory disease); £953 to £3615 (ectopic pregnancy); £546 to £6752 (tubal factor infertility); £159 to £3341 (chronic pelvic pain); £22 to £1008 (epididymitis); £11 to £1459 (neonatal conjunctivitis) and £433 to £3992 (neonatal pneumonia). Total cost of sequelae per case of untreated chlamydia ranged from £37 to £412.

CONCLUSIONS

There was substantial variation in cost per case of chlamydia sequelae used in published chlamydia screening economic evaluations, which likely arose from different assumptions about disease management pathways and the country perspectives taken. In light of this, when interpreting these studies, the reader should be satisfied that the cost estimates used sufficiently reflect the perspective taken and current disease management for their respective context.

Home-based chlamydia testing of young people attending a music festival--who will pee and post?

BACKGROUND

Chlamydia is most common among young people, but only a small proportion of Australian young people are tested annually. Home-based chlamydia testing has been piloted in several countries to increase testing rates, but uptake has been low. We aimed to identify predictors of uptake of home-based chlamydia testing to inform future testing programs.

METHODS

We offered home-based chlamydia testing kits to participants in a sexual behaviour cross-sectional survey conducted at a music festival in Melbourne, Australia. Those who consented received a testing kit and were asked to return their urine or vaginal swab sample via post.

RESULTS

Nine hundred and two sexually active music festival attendees aged 16-29 completed the survey; 313 (35%) opted to receive chlamydia testing kits, and 67 of 313 (21%) returned a specimen for testing. One participant was infected with chlamydia (1% prevalence). Independent predictors of consenting to receive a testing kit included older age, knowing that chlamydia can make women infertile, reporting more than three lifetime sexual partners and inconsistent condom use. Independent predictors of returning a sample to the laboratory included knowing that chlamydia can be asymptomatic, not having had an STI test in the past six months and not living with parents.

CONCLUSIONS

A low proportion of participants returned their chlamydia test, suggesting that this model is not ideal for reaching young people. Home-based chlamydia testing is most attractive to those who report engaging in sexual risk behaviours and are aware of the often asymptomatic nature and potential sequelae of chlamydia infection.

Interventions for young people in Australia to reduce HIV and sexually transmissible infections: a systematic review

Background: Like young people in other developed countries, sexually active young Australians can have an increased risk of acquiring sexually transmissible infections (STIs). This paper reviews intervention programs that aim to reduce the incidence and transmission of HIV and STIs among young people in Australia. Methods: Articles were identified from seven databases. Intervention studies conducted in Australia that included young people aged 12–25 years were reviewed. A two-dimensional matrix consisting of ‘setting’ and ‘intervention type’ was developed to categorise each study. Results: Forty-two studies met the inclusion criteria, and the majority were uncontrolled intervention studies. Of these, 23/42 studies measured participation in chlamydia ± other STI testing and found that the highest participation rates took place in non-clinical and non-general practice health care settings. Four studies facilitated access to testing indirectly, through the internet or other media. Ten studies involved the provision of education and measured its impact on factors such as knowledge, attitudes and/or behaviour. Three studies involved novel immunisation strategies for either hepatitis B or human papillomavirus vaccines. Two studies evaluated the impact of enhanced STI surveillance programs on prevalence rates. Conclusions: Proactive STI testing in non-clinical and some health settings appears feasible and achieves higher testing rates than in general practice; however, more evaluation of testing strategies in general practice settings is required. New technologies such as the internet and SMS are useful adjuncts for influencing behaviours such as condom use and STI testing. Media campaigns that promote STI testing can have a positive impact on testing rates.

Prevalence of Chlamydia trachomatis in a public colposcopy clinic population

BACKGROUND

Chlamydia trachomatis is a major public health issue, with notifications of this sexually transmitted disease continuing to rise in Australia. Women attending colposcopy clinics are referred for treatment of cervical abnormalities often associated with human papilloma virus (HPV) infection. There is evidence that women who have acquired one sexually transmitted infection, such as HPV, are at higher risk of acquiring another. Women attending colposcopy clinics may therefore be at risk of undiagnosed infection with C. trachomatis.

AIM

To determine the prevalence of C. trachomatis in women attending a public metropolitan colposcopy clinic in Victoria.

METHODS

A cross-sectional study was performed. Institutional ethics committee approval and informed consent were obtained. Consecutive women attending the colposcopy clinic completed a questionnaire and had a swab collected from the endocervix for analysis by polymerase chain reaction for C. trachomatis. Positive screens were treated in accordance with best practice. Data were analysed with Minitab Version 2004 (Minitab Inc, State College, PA, USA).

RESULTS

Of 581 women approached to participate in the trial, consent was obtained from 568 women (98%) and final outcome data was available on 560 women (99%). The overall rate of chlamydial infection was 2.1% (95% CI 1.5-2.7%). However, in women aged 25 years or less the rate was 5.8% (95% CI 3.8-7.8%) and in women over 25 years it was only 0.9% (95% CI 0.4-1.4%). Apart from age, no other demographic factor was significantly associated with chlamydial infection.

CONCLUSION

Although the prevalence of chlamydial infection in the colposcopy clinic population as a whole does not warrant a policy for routine screening, screening directed at women aged 25 years or less would gain the greatest yields in terms of cost efficacy. Such a policy should be implemented as standard practice.

One to one interventions to reduce sexually transmitted infections and under the age of 18 conceptions: a systematic review of the economic evaluations

OBJECTIVE

To systematically review and critically appraise the economic evaluations of one to one interventions to reduce sexually transmitted infections (STIs) and teenage conceptions.

DESIGN

Systematic review.

DATA SOURCES

Search of four electronic bibliographic databases from 1990 to January 2006. Search keywords included teenage, pregnancy, adolescent, unplanned, unwanted, cost benefit, cost utility, economic evaluation, cost effectiveness and all terms for STIs, including specific diseases.

REVIEW METHODS

We included studies that evaluated a broad range of one to one interventions to reduce STIs. Outcomes included major outcomes averted, life years and quality adjusted life years (QALY). All studies were assessed against quality criteria.

RESULTS

Of 3,190 identified papers, 55 were included. The majority of studies found one to one interventions to be either cost saving or cost effective, although one highlighted the need to target the population to receive post-exposure prophylaxis to reduce transmission of HIV. Most studies used a static approach that ignores the potential re-infection of treated patients.

CONCLUSION

One to one interventions have been shown to be cost saving or cost effective but there are some limitations in applying this evidence to the UK policy context. More UK research using dynamic modelling approaches and QALYs would provide improved evidence, enabling more robust policy recommendations to be made about which one to one interventions are cost effective in reducing STIs in the UK setting. The results of this review can be used by policy makers, health economists and researchers considering further research in this area.

The cost effectiveness of screening for genital Chlamydia trachomatis infection in Australia

Background: In Australia, there is no published study on the cost effectiveness of screening for chlamydia. The aim of this study was to examine the cost effectiveness of a hypothetical screening programme for chlamydia based on annual opportunistic testing of all women 25 years of age or younger consulting a general practitioner, compared with no screening. Methods: A decision–analytic modelling approach was used to determine the incremental cost effectiveness ratio (ICER) of screening compared with no screening over 25 years. The analysis measured Australian health-care costs and benefits were assessed in terms of quality-adjusted life years (QALYs). Results: The analysis resulted in a cost per QALY of $2968 for screening. One-way sensitivity analyses on all variables, and multi-way sensitivity analyses on some variables, showed a wide range for the cost effectiveness, from dominance (where screening is effective and saves money overall) to an ICER of $67 715 per QALY. Conclusions: The results indicate that annual opportunistic screening for chlamydia in women under 25 is a potentially worthwhile undertaking. However, the analysis also highlights uncertainties around the natural history of chlamydia and the effectiveness of chlamydia screening. Given these uncertainties, the need for further primary data collection in these areas becomes apparent.