Do incentives, reminders or reduced burden improve healthcare professional response rates in postal questionnaires? two randomised controlled trials

Table 1 Response to reminders in RCT A

	Full questionnaire (control)		Incentive		Abridged questionnaire
	N = 102		N = 102		N = 102
	n	%	n	%	n	%
Completed questionnaires returned	43	42.2	52	51.0	46	45.1
Full questionnaire versus Incentive
Absolute percent difference (95% CI) ; p-value	-8.8 ( -22.5 to 4.8);.21
Full questionnaire versus abridged questionnaire
Absolute percent difference (95% CI)	-2.9 (-16.5, 10.7);.67
p value

Percentage difference and 95% confidence intervals were derived from the logistic regression model, a positive difference favours the full questionnaire.