Implementing Germ Defence digital behaviour change intervention via all primary care practices in England to reduce respiratory infections during the COVID-19 pandemic: an efficient cluster randomised controlled trial using the OpenSAFELY platform

Table 4 Process evaluation. Associations between website user rates and consultation rates for intervention practices

	1. All intervention practices (n = 1246)		2. Practices with user rate > 1% (n = 129)
Outcome	Rate ratio (95% CI)	p-value	Rate ratio (95% CI)	p-value
RTIs	0.96 (0.82, 1.14)	0.65	1.07 (0.78, 1.48)	0.68
Acute RTIs	0.96 (0.82, 1.14)	0.65	1.07 (0.78, 1.48)	0.68
Gastrointestinal infections	1.09 (0.90, 1.30)	0.37	1.28 (0.88, 1.86)	0.19
COVID diagnoses	0.98 (0.83, 1.16)	0.84	1.02 (0.73, 1.41)	0.92
COVID symptoms (sensitive)	0.98 (0.82, 1.18)	0.86	0.78 (0.52, 1.17)	0.24
COVID symptoms (specific)	1.23 (1.01, 1.50)	0.04	0.67 (0.40, 1.12)	0.13
Antibiotic use	1.00 (0.85, 1.18)	0.99	0.95 (0.69, 1.31)	0.76
Hospital admissions	1.04 (0.88, 1.23)	0.62	1.02 (0.74, 1.40)	0.91

Rate ratios indicate change in consultation rate for every 10% increase in user rate. Results are shown separately for (1) all intervention practices and (2) for a subset where the user rate was greater than 1% of patients in a practice. All estimates were adjusted for median age, deprivation percentile and the proportion of patients from an ethnic minority

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