Participation rates, response bias and response behaviours in the community survey of the Swiss Spinal Cord Injury Cohort Study (SwiSCI)

Table 3 Description of eligibility, response status and participation rates for all SwiSCI modules

	Abbreviations/Calculation	First module	Second module	Third modules
				PPF-HB module	HSR module	Work module
Total invited	I + R + NC + NE	3807	1922	583	587	383
Eligibility, n
Eligible total	I + R + NC = E_tot	3144	3144	N.a.	N.a.	N.a.
Eligible for module	E_module	3144	1922	572	579	377
Not eligible	NE	663	(55)^a	(12)^a	(9)^a	(7)^a
Double contact		50	(12)	(1)	(1)	(2)
Deceased before invitation		217	N.a.	N.a.	N.a.	N.a.
Inclusion criteria not met		308	(43)	(11)	(8)	(5)
Undeliverable^b		88	0	0	0	0
Response status, n
Participation	I	1922	1549	511	492	328
Refusal	R	845	306	59	79	46
No contact	NC	377	67	1	7	2
Not reached by telephone		191	32	0	0	0
No telephone number		179	22	0	0	0
Deceased after sent out		7	13	1	7	2
Participation rates (%)
Absolute cooperation rate	[I/(I + R)]*100	69.5	83.5	89.6	86.2	87.7
Cumulative cooperation rate	[I/(I + R_tot)]*100	N.a.	57.4	For all 3^rd modules: 49.9
Absolute contact rate	[(I + R)/(I + R + NC)]*100	88.0	96.5	99.8	98.8	99.5
Cumulative contact rate	[(I + R_tot)/(I + R_tot + NC_tot)]*100	N.a.	85.9	For all 3^rd modules: 85.4
Absolute response rate^c	[I/(I + R + NC)]*100	61.1	80.6	89.5	85.1	87.2
Cumulative response rate	[I/(I + R_tot + NC_tot)]*100	N.a.	49.3	For all 3^rd modules: 42.7
Absolute attrition rate	[1- [I/(I + R + NC)]]*100	38.9	19.4	10.5	14.9	12.8
Cumulative attrition rate	[1- (I/(I + R_tot + NC_tot))]*100	N.a.	50.7	For all 3^rd modules: 57.4

Absolute rates always focus on the numbers of a specific module
Abbreviations: PPF-HB Psychological Personal Factors and Health Behavior Module, HSR Health Services Research, N.a. not applicable, tot all modules up to the specific module
^aAlready included in the 663 NE from first module, otherwise participation rates would be biased
^bSee footnote a Table 1
^cCalculation of response rate according to AAPOR’s definition ‘Response Rate 5’ assuming that there are no eligible cases among the cases of unknown eligibility (see footnote a Table 1)

ISSN: 1471-2288