Figure 2: Diagrammatic representation of study design.
First, symptom history was captured using an automated questionnaire
(devised by author [removed for blind peer review] in English,
piloted in ENT clinics in Tanzania and England, and then translated into
Khmer). An initial question asked participants to report ear discharge
(otorrhoea), ear pain (otalgia) and/or hearing loss (we also captured
symptoms of dizziness and tinnitus, but did not use these in subsequent
analysis). Forced responses and skip logic (figure 3) were used to
further define each symptom, including laterality, chronology, and (for
otorrhoea) consistency. The algorithm also collected date on
demographical information, past medical and surgical history and drug
and allergy history. For this study the questionnaire was hosted on the
Cupris platform (Cupris Ltd, London), and data were captured by one of
three ENT specialist nurses who were native Khmer language speakers and
had worked at CSC hospital for 1-6 years.