Recruitment and retention of participants in longitudinal studies after a natural disaster.

Climate change and population growth will increase vulnerability to natural and human-made disasters or pandemics. Longitudinal research studies may be adversely impacted by a lack of access to study resources, inability to travel around the urban environment, reluctance of sample members to attend appointments, sample members moving residence and potentially also the destruction of research facilities. One of the key advantages of longitudinal research is the ability to assess associations between exposures and outcomes by limiting the influence of sample selection bias. However, ensuring the validity and reliability of findings in longitudinal research requires the recruitment and retention of respondents who are willing and able to be repeatedly assessed over an extended period of time. This study examined recruitment and retention strategies of 11 longitudinal cohort studies operating during the Christchurch, New Zealand earthquake sequence which began in September 2010, including staff perceptions of the major impediments to study operations during/after the earthquakes and respondents' barriers to participation. Successful strategies to assist recruitment and retention after a natural disaster are discussed. With the current COVID-19 pandemic, longitudinal studies are potentially encountering some of the issues highlighted in this paper including: closure of facilities, restricted movement of research staff and sample members, and reluctance of sample members to attend appointments. It is possible that suggestions in this paper may be implemented so that longitudinal studies can protect the operation of their research programmes.

Longitudinal Cohort Study of Depression and Anxiety Among Older Informal Caregivers Following the Initial COVID-19 Pandemic Response in Aotearoa New Zealand.

OBJECTIVES: To assess the impact of providing care and conditions of care on psychological wellbeing among older informal caregivers following the initial period of COVID-19 pandemic restrictions in Aotearoa New Zealand. METHODS: Data were from population-based cohorts of older adults participating in the 2020 Health, Work and Retirement longitudinal survey (n = 3839, 17.4% informal caregivers). Changes in symptoms of depression and anxiety over 2018-2020 surveys associated with sociodemographic factors, caregiving, cohabitation with the care recipient, assistance provided with activities of daily living, support in providing care, and opportunity cost of care were assessed. RESULTS: Increased depression, but not anxiety, was associated with providing informal care. Among caregivers, lower living standards and cohabitation were associated with increased depression. Lower living standards, unemployment, and lower help from friend/family networks were associated with increased anxiety. DISCUSSION: Economic hardship and social capital provide targets for supporting psychological wellbeing of older caregivers during periods of pandemic restrictions.