Interventions for encouraging sexual behaviours intended to prevent cervical cancer

 

Abstract

Background

Human papillomavirus (HPV) is the key risk factor for cervical cancer. Continuing high rates of HPV and other sexually transmitted infections (STIs) in young people demonstrate the need for effective behavioural interventions.

Objectives

To assess the effectiveness of behavioural interventions for young women to encourage safer sexual behaviours to prevent transmission of STIs (including HPV) and cervical cancer.

Search methods

Systematic literature searches were performed on the following databases: Cochrane Central Register of Controlled Trials (CENTRAL Issue 4, 2009) Cochrane Gynaecological Cancer Review Group (CGCRG) Specialised Register, MEDLINE, EMBASE, CINAHL, PsychINFO, Social Science Citation Index and Trials Register of Promoting Health Interventions (TRoPHI) up to the end of 2009. All references were screened for inclusion against selection criteria.

Selection criteria

Randomised controlled trials (RCTs) of behavioural interventions for young women up to the age of 25 years that included, amongst other things, information provision about the transmission and prevention of STIs. Trials had to measure behavioural outcomes (e.g. condom use) and/or biological outcomes (e.g. incidence of STIs, cervical cancer).

Data collection and analysis

A narrative synthesis was conducted. Meta-analysis was not considered appropriate due to heterogeneity between the interventions and trial populations.

Main results

A total of 5271 references were screened and of these 23 RCTs met the inclusion criteria. Most were conducted in the USA and in health-care clinics (e.g. family planning).

The majority of interventions provided information about STIs and taught safer sex skills (e.g. communication), occasionally supplemented with provision of resources (e.g. free sexual health services). They were heterogeneous in duration, contact time, provider, behavioural aims and outcomes. A variety of STIs were addressed including HIV and chlamydia. None of the trials explicitly mentioned HPV or cervical cancer prevention.

Statistically significant effects for behavioural outcomes (e.g. increasing condom use) were common, though not universal and varied according to the type of outcome. There were no statistically significant effects of abstaining from or reducing sexual activity. There were few statistically significant effects on biological (STI) outcomes. Considerable uncertainty exists in the risk of bias due to incomplete or ambiguous reporting.

Authors' conclusions

Behavioural interventions for young women which aim to promote sexual behaviours protective of STI transmission can be effective, primarily at encouraging condom use. Future evaluations should include a greater focus on HPV and its link to cervical cancer, with long-term follow-up to assess impact on behaviour change, rates of HPV infection and progression to cervical cancer. Studies should use an RCT design where possible with integral process evaluation and cost-effectiveness analysis where appropriate. Given the predominance of USA studies in this systematic review evaluations conducted in other countries would be particularly useful.

 

Plain language summary

Interventions for encouraging sexual behaviours intended to prevent cervical cancer

Young women are at high risk of contracting sexually transmitted infections (STIs), including types of human papillomavirus (HPV) that can cause cervical cancer. High rates of STIs among young people highlight a need for effective strategies to prevent the spread of infections. Although behavioural approaches (e.g. using condoms consistently) could protect against STIs and cervical cancer, there is a lack of evidence on which strategies would be most effective in practice. This systematic literature review was conducted to identify which types of behavioural strategy have been tested and to assess their effectiveness.

Eight electronic bibliographic databases were searched up to the end of 2009. To be considered relevant, studies had to use a randomised controlled trial (RCTs) design; include young women up to the age of 25 years; report one or more behavioural interventions that aimed to prevent STIs or cervical cancer; and record outcomes which were either behavioural (e.g. condom use) or biological (incidence of STIs or cervical cancer).

Searches identified 5271 bibliographic records. Screening the records independently by two review authors identified 23 relevant randomised controlled trials (RCTs). The trials were mostly conducted in the USA (21 trials) and in health-care (e.g. family planning) clinics (14 trials), with only four in educational settings. Trial participants had mixed socio-economic and demographic characteristics and most were sexually experienced. The interventions mostly provided information about STIs and taught safer sex skills (e.g. communication with partners), occasionally supplemented with provision of resources (e.g. free sexual health services). Interventions varied considerably in duration, contact time, provider, behavioural aims and outcomes. A variety of STIs were addressed including HIV and chlamydia, but not explicitly HPV.

The most common behavioural outcome (measured in 19 trials) was condom use for vaginal intercourse. Sexual partners, sexual abstinence and STIs were reported in four, two and 12 trials respectively. In terms of statistically significant effects, some interventions improved condom-related behaviour and reduced the number of sexual partners, but none affected the frequency of sexual episodes. Effects of interventions on STIs were limited. None of the interventions appeared to be harmful. The methods used in the trials were not always well described making it difficult to tell whether their results may have been biased. In conclusion, although some behavioural interventions improve condom-related behaviour, trials have been predominantly in USA healthcare settings, did not specifically address HPV and were too different to enable a most effective type of intervention to be identified.

 

Resumen

Antecedentes

Intervenciones para la prevención del cáncer de cuello de útero mediante modificaciones de la conducta sexual

El virus del papiloma humano (HPV) es el factor de riesgo clave del cáncer de cuello de útero. Las tasas altas continuas de infección por el HPV y por otras infecciones de transmisión sexual (ITS) en los jóvenes demuestran la necesidad de intervenciones conductuales efectivas.

Objetivos

Evaluar la efectividad de las intervenciones conductuales en mujeres jóvenes para estimular conductas sexuales más seguras y prevenir la transmisión de las ITS (incluido el HPV) y el cáncer de cuello de útero.

Estrategia de búsqueda

Se hicieron búsquedas sistemáticas en la literatura en las siguientes bases de datos: Registro Cochrane Central de Ensayos Controlados (Cochrane Central Register of Controlled Trials) (CENTRAL, número 4, 2009), Registro Especializado de Ensayos Controlados del Grupo de Revisión Cochrane de Cáncer Ginecológico (Cochrane Gynaecological Cancer Review Group, CGCRG), MEDLINE, EMBASE, CINAHL, PsychINFO, Social Science Citation Index y en Trials Register of Promoting Health Interventions (TRoPHI), hasta el final de 2009. Todas las referencias se revisaron para su inclusión con respecto a los criterios de selección.

Criterios de selección

Ensayos controlados con asignación aleatoria (ECAs) de intervenciones conductuales en mujeres jóvenes hasta la edad de 25 años que incluyeran, entre otras, la provisión de información acerca de la transmisión y la prevención de las ITS. Los ensayos tenían que evaluar medidas de resultado conductuales (p.ej. uso de preservativos) o resultados biológicos (p.ej. incidencia de ITS, cáncer de cuello de útero).

Obtención y análisis de los datos

Se realizó una síntesis narrativa. El metanálisis no se consideró apropiado debido a la heterogeneidad entre las intervenciones y las poblaciones de los ensayos.

Resultados principales

Se examinó un total de 5 271 referencias y de éstas, 23 ECAs cumplieron con los criterios de inclusión. La mayoría se realizó en los EE.UU. y en consultorios de asistencia sanitaria (p.ej. planificación familiar).

En su mayoría las intervenciones proporcionaron información acerca de las ITS y enseñaron habilidades para una relación sexual más segura (p.ej. comunicación), ocasionalmente complementado con provisión de recursos (p.ej. servicios de salud sexual gratis). Éstas fueron heterogéneas en cuanto a la duración, el tiempo de contacto, el profesional, los objetivos conductuales y las medidas de resultado. Se abordaron varias ITS, incluidas las infecciones por VIH y clamidia. Ningún ensayo mencionó explícitamente la prevención del HPV o del cáncer de cuello de útero.

Fueron frecuentes los efectos estadísticamente significativos de los resultados conductuales (p.ej. mayor uso de preservativos) aunque no universales, y variaron según el tipo de resultado. No hubo efectos estadísticamente significativos para la abstinencia ni la reducción de la actividad sexual. Hubo pocos efectos estadísticamente significativos sobre las medidas de resultado biológicas (ITS). Existe incertidumbre considerable acerca del riesgo de sesgo debido a informe incompleto o ambiguo.

Conclusiones de los autores

Las intervenciones conductuales en mujeres jóvenes que intentan promover conductas sexuales que las protejan de la transmisión de las ITS pueden ser efectivas, principalmente la estimulación del uso de preservativos. Las evaluaciones futuras deben incluir un mayor énfasis en el HPV y su vínculo con el cáncer de cuello de útero, con seguimiento a largo plazo para evaluar la repercusión sobre el cambio de conductas, las tasas de infección por el HPV y la progresión al cáncer de cuello de útero. De ser posible, los estudios deben utilizar un diseño de ECAs con una evaluación integral de los procesos y un análisis de la relación costeefectividad cuando sea apropiado. Debido al predominio de los estudios de EE.UU. en esta revisión sistemática, las evaluaciones realizadas en otros países serían particularmente útiles.

Traducción

Traducción realizada por el Centro Cochrane Iberoamericano