Using a birth cohort to study ageing: representativeness and response rates in the National Survey of Health and Development

Abstract

Britain’s oldest birth cohort study, the MRC National Survey of Health and Development (NSHD) provides data to explore life time influences on ageing. The latest data collection was undertaken between 2006 and 2011 when study members were aged 60–64 and consisted of postal and pre-assessment questionnaires to eligible study members, followed by invitation to attend one of six clinical research facilities (CRFs) across the UK for clinical assessments, and dietary diaries and activity monitors in the days following the CRF visit. The option of a home visit for clinical assessments was provided if the study member refused or was unable to attend the CRF. We examined response and attrition, here describing rates overall and for postal and clinical assessment modes of data collection, identifying socioeconomic and health-related predictors of response, and assessing the continued representativeness of the sample. In total, 2,661 (84 % of the target sample) responded. Lower educational attainment, lower childhood cognition and lifelong smoking independently predicted lower likelihood of both overall response and CRF cooperation. At 53 years, not owning one’s home and not being married predicted lower likelihood of overall response whereas manual social class and obesity predicted lower likelihood of CRF cooperation. Providing for collection of biomedical data in the home and use of assessment instruments and modes to retain study members with lower education attainment, lower cognition and poorer health behaviours should be priorities for helping reduce attrition amongst vulnerable ageing study members.

Combined Impact of Smoking and Early-Life Exposures on Adult Lung Function Trajectories

“…Prospective data have been collected regularly from this nationally representative cohort of men and women since birth with participation rates of generally 80% or higher (13)(14)(15). At age 43 years, 3632 were interviewed at home by research nurses.…”

“…Loss to follow up was due to death (7%), emigration (11%), refusal (16%) and failure to trace (5%) (13). Similar visits were made at ages 53 (14) and at 60-64 years (15). At 60-64 the participating sample still remained broadly representative of native born British men and women of the same age (15).…”

Physical and cognitive capability in mid-adulthood as determinants of retirement and extended working life in a British cohort study

“…Non-responders were over-represented in groups with low educational attainment, more disadvantaged occupational social class, unemployed or long-term sick-or work-disabled, poorer cognitive performance and fewer health-promoting behaviors (24). Analyses of retirement reason and timing excluded those who retired at ≤53 years (N=490) or who had not been in paid work from age ≥36 (N=20).…”

Associations of Midlife to Late Life Fatigue With Physical Performance and Strength in Early Old Age

“…22 This cohort has been assessed prospectively at more than 20 time points across life from birth onwards.…”

“…22,23 Of the 5362 original study members, at age 60-64 years the study team was still in contact with 3163 (59%); 718 had died, 594 had previously withdrawn from the study, 567 lived abroad and 320 had been untraceable for more than ten years. Study members received postal questionnaires and were invited for clinic visits.…”