Table 1.

Components of the intervention

Intervention component	Description
Cell phones	Distribution of the non-smart mobile phones by the research team to health facilities in the intervention clusters (districts) either as a shared-use phone or as individual-use phone. Each midwife was provided an individual-use phone and each health facility had a shared-use phone.
CUG	A network of SIM cards with unlimited access to make free phone calls to other SIM cards within the network. All intervention users constituted membership of the CUG.
Text messaging	Sending of up to 100 free short messaging service per month to SIM cards in as well as outside the CUG.
Data bundle	System that provides up to 25 MB of free data per month to the project SIM cards.
Monthly credit top-up	*An automated system from the telecommunication company that topped up 2.50 cedis (US$0.70) worth of Vodafone credit on project SIM cards each month. This top up credit could be used at the discretion of the health worker for making calls, texting or browsing the internet beyond the limits set for text messaging and data bundle aforementioned.
Reminders	Monthly reminders sent to the intervention users reminding them of the availability of the USSD protocols.
Training	Health workers were trained on how to use the intervention first at a group gathering in each intervention district capital before the start of the cluster randomised controlled trial and then at least once during monitoring visits in their individual health facilities during intervention implementation.
USSD	A communications protocol that allows a two-way exchange of data between a phone user and preprogramed information linked to short codes stored on a remote computer of a telecommunication company. This makes it more interactive than text messaging. Each response message linked to a short code is limited to a length of 150–182 alphanumeric characters. In the intervention districts, it was used for requesting and receiving text-message-based standard emergency obstetric and neonatal protocols on the request of a health worker. Access to the USSD was limited to only project SIM cards (CUG members). For CUG members, access to the USSD was free and with no limits to the number of times the USSD could be accessed.

*Exchange rate of US$1=3.56 cedis is based on the Bank of Ghana exchange rate at start of the intervention in August 2015.

CUG, Closed User Group; SIM, Subscriber Identification Module; USSD, Unstructured Supplementary Service Data.