Background

This section introduces the main concepts related to the research conducted in this thesis. Firstly, human papillomavirus (HPV) and the etiology of cervical cancer are introduced. Secondly, cervical cancer prevention methods are presented, with a specific focus on screening services. Thirdly, the burden of cervical cancer and cervical cancer prevention methods in Tanzania are presented. This is followed by an introduction of mobile phone accessibility in Africa and Tanzania. Finally, the concept of mobile health (mHealth) interventions is introduced. 

Aim and Objectives

The aim of this PhD thesis is to examine the effect of one-way text message trials in Africa, and specifically in relation to follow-up cervical cancer screening attendance in Tanzania. Further, it aims to understand what motivates and prevents women from attending screening in Tanzania. Specifically, the thesis has the following three objectives: 1. To provide an overview of one-way text message trials in Africa and summarise their effect on medicine adherence and appointment attendance compared to no text messages [paper I] 2. To assess the effect of one-way text messages compared to no text messages on attendance to a 14-months follow-up cervical cancer screening appointment among Tanzanian women who have tested positive to a rapid HPV test [paper II: protocol; paper III: results] 3. To understand causes of attendance and non-attendance to cervical cancer screening among HPV-positive women in Tanzania [paper IV] 

Methods

The aim of the systematic review and meta-analysis was to summarise the effect of oneway text messages on appointment attendance and medicine adherence (paper I). PubMed, Embase, the Global Health Library, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched in any language from inception to 18 April 2018. ClinicalTrials.gov, the Pan African Clinical Trial Registry (PACTR), and the International Clinical Trial Registry Platform (ICTRP) were searched for unpublished or ongoing trials, and United Nations and World Bank databases were searched for reports including relevant trials. The protocol was registered in PROSPERO (ID: CRD42018081062) prior to study conduct; 26 corresponding authors were contacted for clarification or to obtain missing data. Inclusion criteria were published and unpublished randomised controlled trials (RCTs) set in Africa, and trial participants were healthcare clients or guardians for healthcare clients. At least one intervention arm had to be exclusive one-way text messages, and the trials had to have a control group which received standard care, placebo- or no text messages. An overall descriptive analysis of all trials was performed, and meta-analyses were restricted on the outcomes “appointment attendance” and “medicine adherence”, which were regarded to be uniform. Meta-analyses were carried out using Review Manager 5.355. A random-effects model with the Mantel-Haenszel method for dichotomous data was used to calculate pooled risk ratios (RRs) and estimate 95% confidence intervals (CIs) for medicine adherence. As one cluster trial10 was included in the meta-analysis for appointment attendance, a pooled odds ratio (OR) using the generic-inverse variance method was used in order to take clustering into account. Heterogeneity was assessed using I2. Subgroup analyses were performed on clinical conditions and on low risk versus high risk of bias trials. Risk of bias was judged by use of the Cochrane Risk of Bias Tool56. Further, sensitivity analyses were conducted using fixed-effect models, excluding the cluster trial, and post-hoc on trials published in journals on Beall’s list of potential predatory publishers57.

Results

Descriptive analysis Thirty-eight trials were included into the review; 25 were published7-10,46-52,54,58-70 and 13 were unpublished71-83, of which nine were ongoing71-77,79,80. All but one trial was set in SubSaharan Africa [Figure 6], and most trials concerned the clinical area of HIV followed by immunisation and reproductive health.