Quantitative methods
AOM
We examined the symptoms associated with a diagnosis of AOM at day 0 and 7, namely, the AOM-SOS and AOM-FS scores and individual items, and other reported symptoms collected at the same time. We compared the symptoms reported in children who had persistent or resolved AOM at day 7.We studied how AOM-SOS and the AOM-FS scales compared in terms of completeness of data and change in scores over time, and whether they yielded similar results as determined by their correlation. Evidence for construct validity can be determined by whether different AOM scales yield similar results [Finally, we studied how responsive the scales were to clinical change between enrolment and day 7 by examining the data on the children who had GP review at day 7. Effectiveness of AOM symptom scales in the research setting can be determined by the degree they detect significant clinical change over time [All data were blinded to trial arm, with data management and analyses carried out using SAS 9.4 software (SAS Institute Inc., Cary, NC, USA) and Python version 3.11.0 (Python Software Foundation). Both version 3 and 4 of AOM-SOS were tested in each analysis to compare their performance. “Don’t know” for any item in the AOM-SOS was handled as missing data for the whole scale. “Don’t know” responses for the GP adjudication of AOM resolution at day 7 or other symptoms were also handled as missing data. Data from the take-home diary (AOM-FS) were not included in the quantitative analysis.