Improving sexual health through partner notification: the LUSTRUM mixed-methods research Programme including RCT of accelerated partner therapy
Authors: Estcourt Claudia S , Mapp Fiona , Woode Owusu Melvina , Low Nicola , Flowers Paul , Copas Andrew , Roberts Tracy E , Mercer Catherine H , Saunders John , Nandwani Rak , Althaus Christian L , Stirrup Oliver , Symonds Merle , Howarth Alison R , Johnson Anne M , Okeke Ogwulu Chidubem , Pothoulaki Maria , Vojt Gabriele , Wayal Sonali , Brice Susie , Comer-Schwartz Alex , Tostevin Anna , Williams Eleanor , Lasoye Sarah , McQueen Jean , Abdali Zainab , Cassell Jackie A 
Published: June 2023

Background
Sexually transmitted infections disproportionately affect young people and men who have sex with men. Chlamydia is Britain’s most common sexually transmitted infection. Partner notification is a key intervention to reduce transmission of sexually transmitted infections and human immunodeficiency virus but is hard to implement. Accelerated partner therapy is a promising new approach.

Objectives

determine the effectiveness, costs and acceptability of accelerated partner therapy for chlamydia in heterosexual people
model the cost effectiveness of accelerated partner therapy and impact on chlamydia transmission
develop and cost partner notification interventions for men who have sex with men.

Design
Mixed-methods study to develop a new sex partner classification and optimise accelerated partner therapy; cluster crossover randomised controlled trial of accelerated partner therapy, with process and cost-consequence evaluation; dynamic modelling and health economic evaluation; systematic review of economic studies of partner notification for sexually transmitted infections in men who have sex with men; qualitative research to co-design a novel partner notification intervention for men who have sex with men with bacterial sexually transmitted infections.

Settings
Sexual health clinics and community services in England and Scotland.

Participants
Women and men, including men who have sex with men and people with mild learning disabilities.

Interventions
Accelerated partner therapy offered as an additional partner notification method.

Main outcome measures
Proportion of index patients with positive repeat chlamydia test (primary outcome); proportion of sex partners treated; costs per major outcome averted and quality-adjusted life-year; predicted chlamydia prevalence; experiences of accelerated partner therapy.

Data sources
Randomised controlled trial: partnership type, resource use, outcomes, qualitative data: economic analysis, modelling and systematic review: resource use and unit costs from the randomised controlled trial, secondary sources.

Results
The sex partner classification defined five types. Accelerated partner therapy modifications included simplified self-sampling packs and creation of training films. We created a clinical management and partner notification data collection system.
In the randomised controlled trial, all 17 enrolled clinics completed both periods; 1536 patients were enrolled in the intervention phase and 1724 were enrolled in the control phase. Six hundred and sixty-six (43%) of 1536 index patients in the intervention phase and 800 (46%) of 1724 in the control phase were tested for Chlamydia trachomatis at 12–24 weeks after contact tracing consultation; 31 (4.7%) in the intervention phase and 53 (6.6%) in the control phase had a positive Chlamydia trachomatis test result [adjusted odds ratio 0.66 (95% confidence interval 0.41 to 1.04); p = 0.071]. The proportion of index patients with ≥ 1 sex partner treated was 88.0% (775/881) in intervention and 84.6% (760/898) in control phase, adjusted odds ratio 1.27 (95% confidence interval 0.96 to 1.68; p = 0.10). Overall, 293/1536 (19.1%) index patients chose accelerated partner therapy for 305 partners, of which partner types were: committed/established, 166/305 (54.4%); new, 85/305 (27.9%); occasional, 45/305 (14.8%); and one-off, 9/305 (3.0%). Two hundred and forty-eight accepted accelerated partner therapy and 241 partners were sent accelerated partner therapy packs, 120/241 (49.8%) returned chlamydia/gonorrhoea samples (78/119, 65.5%, positive for chlamydia, no result in one), but only 60/241 (24.9%) human immunodeficiency virus and syphilis samples (all negative). The primary outcomes of the randomised trial were not statistically significantly different at the 5% level. However, the economic evaluation found that accelerated partner therapy could be less costly compared with routine care, and mathematical modelling of effects and costs extrapolated beyond the trial end points suggested that accelerated partner therapy could be more effective and less costly than routine care in terms of major outcome averted and quality-adjusted life-years’. Healthcare professionals did not always offer accelerated partner therapy but felt that a clinical management and partner notification data collection system enhanced data recording.
Key elements of a multilevel intervention supporting men who have sex with men in partner notification included: modifying the cultural and social context of men who have sex with men communities; improving skills and changing services to facilitate partner notification for one-off partners; and working with dating app providers to explore digital partner notification options.
The systematic review found no evaluations of partner notification for men who have sex with men. Modelling of gonorrhoea and human immunodeficiency virus co-infection in men who have sex with men was technically challenging.

Limitations
In the randomised controlled trial, enrolment, follow-up and repeat infections were lower than expected, so statistical power was lower than anticipated. We were unable to determine whether accelerated partner therapy sped up partner treatment. Mathematical modelling of gonorrhoea/human immunodeficiency virus co-infection in men who have sex with men remained at an experimental stage. It was not feasible to include healthcare professionals in the men who have sex with men intervention development due to the COVID-19 pandemic.

Conclusions
Although the evidence that the intervention reduces repeat infection was not conclusive, the trial results suggest that accelerated partner therapy can be safely offered as a contact tracing option and is also likely to be cost saving, but is best suited to sex partners with emotional connection to the index patient. The Programme’s findings about classification of sexual partner types can be implemented in sexual health care with auditable outcomes.

Future work
Further research is needed on how to increase uptake of accelerated partner therapy and increase sexually transmitted infections self-sampling by partners; understand how services can use partnership-type information to improve partner notification, especially for those currently underserved; overcome challenges in modelling sexually transmitted infections and human immunodeficiency virus co-infection in men who have sex with men; develop and evaluate an intervention to optimise partner notification among men who have sex with men, focusing on one-off partnerships.

Trial registration
This trial is registered as ISRCTN15996256.

Funding
This award was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research Programme (NIHR award ref: RP-PG-0614-20009) and is published in full in Programme Grants for Applied Research; Vol. 12, No. 2. See the NIHR Funding and Awards website for further award information.