Study retention and attrition in a longitudinal cohort study including patient-reported outcomes, fieldwork and biobank samples: results of the Netherlands quality of life and Biomedical cohort study (NET-QUBIC) among 739 head and neck cancer patients and 262 informal caregivers

Table 3 Sociodemographic and clinical characteristics of informal caregivers that participated in the various components (PROMs, biobank) of NET-QUBIC at baseline

	PROMs Yes N = 228	PROMs No N = 34	P-value	Biobank Yes N = 238	Biobank No N = 24	P-value
Gender, n (%)
Men	62 (27%)	8 (24%)	0.65	61 (26%)	9 (38%)	0.21
Women	166 (73%)	26 (76%)		177 (74%)	15 (63%)
Age, mean ± SD years	59.3 ± 11.3	55.7 ± 13.3	0.09	58.9 ± 11.7	57.7 ± 10.1	0.63
Relation informal caregiver – patient^a, n (%)			0.14^b			0.61^b
Partner	194 (85%)	25 (76%)		200 (84%)	19 (83%)
Daughter/son	26 (11%)	5 (15%)		27 (11%)	4 (17%)
Other (i.e. sibling, friend, ex-partner)	7 (3%)	3 (9%)		10 (4%)	0 (0%)

Informal caregivers with PROMs data or biobank samples may have missing data on specific components of the assessment. Results on the representativeness of data for a specific research question may thus differ from above results. Groups were compared using chi square tests, unless otherwise specified. Significant p-values (p < 0.05) were printed in bold
^aMissing in two informal caregivers
^bCompared using Fisher Exact Test
Abbreviations: PROMs patient-reported outcome measure, SD standard deviation

ISSN: 1471-2288