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WHISPER and SHOUT - mHealth interventions among Kenyan sex workers

WHISPER is a mobile phone-based health promotion (mHealth) intervention in which text messages will be sent to female sex workers in Mombasa, Kenya.

The messages address pregnancy prevention and other sexual and reproductive health (SRH) topics, including HIV/ STI prevention and gender based violence, to improve FSWs’ knowledge and encourage them to adopt healthier behaviours.

The intervention will be tested in a randomised controlled trial to determine whether it results in fewer unintended pregnancies.

The participants receiving the WHISPER messages will be a compared to a second group receiving messages about nutritional health (the SHOUT intervention). Topics include nutritional needs, particularly iron and other micronutrients, locally appropriate food preparation and purchasing tips, water sanitation and hygiene, and food safety. The aim is to improve nutrition and reduce iron deficiency anaemia, and the rate of anaemia will be compared between the SHOUT and WHISPER groups. In other words, each intervention acts as the equal attention control group for the other.

The messages for both groups are based on health promotion theory and consultation with FSWs in Mombasa to make them relevant, engaging and effective. As well as simple stand-alone texts, participants will receive stories about sex workers in similar circumstances, overcoming familiar challenges and barriers in order to change their behaviour – for example by using more effective long term contraceptive methods or eating a greater diversity of freshly foods. Participants will also be able to text into the system to request further information via automated response codes, without bearing the cost.

The project is a collaboration between the International Centre for Reproductive Health (ICRH, Kenya) and the Burnet Institute, along with collaborating investigators from other institutions. ICRH is a local NGO with a long history of providing services and support to FSWs via outreach and drop-in clinics in Mombasa, including STI/HIV testing, pregnancy testing, counselling, and support for sexual and gender-based violence. ICRH has a respected role in the sex work community in Mombasa, and close links with other local community-based organisations working with FSWs.

Background/rationale for the study:

Reducing unmet need for contraception could prevent 54 million unintended pregnancies, result in 26 million fewer (often unsafe) abortions, and prevent 79,000 maternal and 600,000 newborn deaths globally each year. Female sex workers (FSW) in Africa carry a markedly disproportionate burden of reproductive health morbidities, experiencing considerable unmet need for family planning and high incidence of unintended pregnancy.

In Kenya, our previous longitudinal research showed over one quarter (27%) of FSWs have an unintended pregnancy each year. mHealth (mobile phone health) interventions are increasingly recognised for their enormous potential to reach large numbers of people across diverse populations segments and provide sustainable population-level platforms for preventive health in resource-constrained settings.

Our previous trials in Australia showed mHealth interventions significantly increased sexual and reproductive health knowledge and service uptake. Moreover, recent formative research among FSW in Kenya demonstrated high mobile phone use and ownership, and high levels of acceptability to receive SMS health messages.


Primary aim (WHISPER):

To assess the effectiveness of a 12-month mobile phone-based sexual and reproductive health promotion intervention to reduce the incidence of unintended pregnancy among FSWs in Kenya. The primary outcome is the incidence of unintended pregnancy over 12 months of follow-up.

Primary aim (SHOUT):

To assess the effectiveness of a 12-month mobile phone-based nutritional health promotion intervention on nutritional status among FSWs in Kenya. The primary outcome is the prevalence of anaemia (haemoglobin <10.0 g/dL) among study participants at month 12.


i) FSWs exposed to the sexual and reproductive health promotion intervention (WHISPER) will experience fewer unintended pregnancies compared to FSWs exposed to the nutrition intervention.
ii) FSWs exposed to the mobile phone-based nutrition intervention (SHOUT) will experience lower rates of anaemia than FSWs exposed to the SRH intervention.

Enrolment for the WHISPER trial is due to commence in July 2016, with follow up to be completed by November 2017

The study has two phases:

Phase 1 – Develop and pilot the mHealth intervention (due to be completed in May 2016):

The research team has been working with FSW in Mombasa, Kenya, to develop and test the mHealth intervention and control packages. Six participatory message development workshops have been conducted with FSWs for both SRH and nutrition messages, and the intervention modified accordingly. One-on-one interviews are being held with FSWs to test the near-final message content and usability of the mobile phone platform.

Phase 2 – Cluster Randomised Controlled Trial (due to commence in July 2016):

We will conduct a cluster randomised controlled trial to assess the effectiveness of our SMS-based mHealth interventions. Eligible women will be recruited from sex work venues (our clusters) by well-established peer outreach workers. FSWs will be randomised to the SRH or nutrition intervention (equal-attention control), with assessments done at baseline, six, and 12 months follow-up.

Semi-structured face-to-face interviews will be conducted by trained research assistants at 0, 6, and 12 months in a dedicated research space at two local drop-in centres linked to health facilities.

The primary study outcome for WHISPER is the incidence of unintended pregnancy over 12 months of follow-up. An unintended pregnancy is defined as one that is mistimed, unplanned, or unwanted at the time of conception. A psychometrically-validated 6-item questionnaire (London Measure of Unintended Pregnancy) is used to score pregnancy intention. Women will be asked about pregnancy intentions (self-reported and before any pregnancy occurred) at baseline, 6 and 12 months.

Secondary outcomes include the proportion of FSWs using modern contraceptive methods and condoms consistently (dual protection); proportion using long-acting reversible contraceptive methods or injectable contraceptives; incidence of HIV and self-reported abortion, and the median score in contraceptive knowledge.

The primary study outcome for SHOUT is the prevalence of anaemia at 12 months of follow-up. Secondary outcomes include mean haemoglobin levels, proportion of FSWs with malnutrition, either underweight (BMI < 18.5kg/m2) or overweight (BMI ≥25 kg/m2), and the proportion reporting nutritious diet, and median score in nutrition knowledge.

If shown to be effective in this trial, mHealth interventions could be incorporated into broader SRH and/or nutrition strategies for FSWs in Africa and elsewhere, and has the potential to be scaled up for use with other women at a population level at low cost.


Burnet Institute

Contact Burnet Institute for more information about the project


Funding Partners

  • NHMRC project grant

Partners + Collaborators

  • International Centre for Reproductive Health, Kenya
  • FHI 360, USA
  • Aga Khan University, Nairobi
  • University of Nairobi
  • Kenya University of the Witwatersrand, South Africa