Refusal to consent to storage and use of biobank samples in Sweden in 2005 and 2006

	Sample series included*	2005				2006
		Rate	Rate in % (95% CI)	IQR for rate		Rate	Rate in % (95% CI)	IQR for rate
Preliminary refusal to consent	72	1656/1 191 176	0.139 (0.132 to 0.146)	0.031-0.123		1806/1 208 717	0.149 (0.143 to 0.156)	0.022-0.097
Confirmed refusal to consent	83	954/1 442 998	0.066 (0.062 to 0.070)	0.000-0.075		888/1 466 659	0.061 (0.057 to 0.065)	0.007-0.056
Specific refusal to consent	79	224/1 401 572	0.016 (0.014 to 0.018)	0.000-0.019		234/1 424 517	0.016 (0.014 to 0.019)	0.000-0.017
Withdrawal of consent	69	66/1 168 634	0.0056 (0.0043 to 0.0070)	0.0000-0.0061		58/1 194 676	0.0049 (0.0036 to 0.0061)	0.0000-0.0049
Unable to consent	73	2469/1 218 372	0.20 (0.19 to 0.21)	0.00-0.23		3639/1 239 765	0.29 (0.28 to 0.30)	0.00-0.09
System error	74	4049/1 213 496	0.33 (0.32 to 0.34)	0.00-0.02		2376/1 236 391	0.19 (0.18 to 0.20)	0.00-0.00

IQR=interquartile range.

*Not all 83 sample series (groups of samples by type and geographical location) had data for each variable. Several rates fall outside corresponding interquartile ranges, which reflects presence of influential outliers.