Exploring patterns of response across the lifespan: the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) study

Abstract

BackgroundWith declining rates of participation in epidemiological studies there is an important need to attempt to understand what factors might affect response. This study examines the pattern of response at different adult ages within a contemporary cross-sectional population-based cohort, the Cambridge Centre for Ageing and Neuroscience (Cam-CAN).MethodsUsing logistic regression, we investigated associations between age, gender and Townsend deprivation level for both participants and non-participants. Weighted estimates of the odds ratios with confidence intervals for each demographic characteristic were calculated. Reasons given for refusal were grouped into three broad categories: ‘active’, ‘passive’ and illness preventing interview.ResultsAn association of age and participation was found, with individuals in middle age groups more likely to participate (age group 48–57 OR: 1.8, 95% CI: 1.5–2.2 and age group 58–67 OR: 2.1, 95% CI: 1.7–2.4). Overall, there was no difference in participation between men and women. An association with deprivation was found, with those living in the most deprived areas being the least willing to participate (fifth quintile OR: 0.6, 95% CI: 0.5–0.7). An interaction between age and gender was found whereby younger women and older men were more likely to agree to participate (p = 0.01).ConclusionOur findings highlight some of the factors affecting recruitment into epidemiological studies in the UK and suggest that targeted age-specific recruitment strategies might be needed to increase participation rates in future cohort investigations.Electronic supplementary materialThe online version of this article (10.1186/s12889-018-5663-7) contains supplementary material, which is available to authorized users.

The effects of age on resting‐state BOLD signal variability is explained by cardiovascular and cerebrovascular factors

“…T A B L E 1 Participants' demographic information, grouped by decile in accordance with the original design of the Cam-CAN cohort (Green et al, 2018;Shafto et al, 2014 The EPI data were unwarped (using field-map images) to compensate for magnetic field inhomogeneities, realigned to correct for motion, and slice-time corrected to the middle slice. The normalization parameters from the T1 image processing were then applied to warp functional images into MNI space.…”

Cognitive Diversity in a Healthy Aging Cohort: Cross-Domain Cognition in the Cam-CAN Project

“…Further information about the recruitment, exclusion criteria, and contents of the testing stages can be found in Shafto et al 2014, Taylor et al (2017), and Green et al (2018). Further details of exclusion and refusals in Stage 1 can be found in Green et al (2018) and in Stages 2 and 3 can be found in Schweizer et al (2019). Further details on the contents of the Cam-CAN data repository and information on how to access it can be found in Taylor et al (2017) or at cam-can.com.…”

“…Participants were recruited into Stage 1 from the Cambridge, UK community via their general practitioner (GP) surgeries. Green, Bennett, Brayne, Cam-CAN, and Matthews (2018) provide details about recruitment and exclusion, where out of 7,616 eligible participants who were initially approached, 2,680 (35.2%) were ultimately interviewed. Active refusals such as being too busy (61% of refusals; N = 3,008) and illness (35.6% of refusals; N = 1,756) made up the majority of refusals at this stage.…”

“…Active refusals such as being too busy (61% of refusals; N = 3,008) and illness (35.6% of refusals; N = 1,756) made up the majority of refusals at this stage. Green et al (2018) examined several factors affecting participation including gender, age, and deprivation. Key findings included no main effect of gender, evidence that middle-aged participants were more likely to volunteer than younger or older participants, and the finding that deprivation affected participation, especially in older adults.…”

“…First, although Cam-CAN recruitment was population-based, it was not population-representative, and participants who completed full cognitive assessments were qualified to undergo cognitive neuroscience experiments including neuroimaging (see , for a description of participant selection for testing stages). As detailed in the "Method" section, Green et al (2018) suggest that both age and deprivation may affect initial participation rates in Stage 1, although characteristics of participants who dropped out during Stage 2 have not yet been fully assessed.…”