Table 4. Summary of results.

OD, odds ratio; HR, hazards ratio; AMD, adjusted mean difference

Results
Returns, n/total (%)			OR	95% CI	p-value
Pen	No pen	Overall
493/728 (67.7)	469/725 (64.7)	962/1453 (66.2)	1.15	0.92, 1.43	0.22
Time to response (days), median (IQR)			HR	95% CI	p-value
Pen	No pen	Overall
15 (9-33)	18 (9-37)	16 (9-35)	1.12	0.98, 1.27	0.09
Completeness of response, mean (SD)			AMD	95% CI	p-value
Pen	No pen	Overall
4.9 (0.4)	4.9 (0.4)	4.9 (0.4)	-0.01	-0.06, 0.05	0.77
Reminder sent, n/total (%)			OR	95% CI	p-value
Pen	No pen	Overall
339/728 (46.6)	369/725 (50.9)	708/1453 (48.7)	0.83	0.68, 1.02	0.08