Table 4.

Collection of host trial primary outcome data at 24 months during home or clinic visit by factorial margins

	No SMS notification for questionnaires (n = 702)	SMS notification for questionnaires (n = 692)	£10 voucher at 24-month visit (n = 695)	£10 voucher before 24-month visit (n = 699)
Host trial primary outcome data collected during home or clinic visit	558 (79%)	565 (82%)	566 (81%)	557 (80%)
Adjusted risk difference (95% CI)		2.4% (−1.8 – 6.5%)		−1.9% (−6.0 – 2.3%)
Adjusted odds ratio (95% CI)		1.15 (0.88 – 1.50)		0.89 (0.69 – 1.17)

Data shown are n (%) using the number randomised to each group as the denominator

Estimates are adjusted for host trial allocation

Odds ratio for interaction between study within a trial (SWAT) interventions from logistic regression model 0.67 (95% CI 0.39 – 1.14, p value 0.14)