So far, migration literature has been heavily skewed towards the working-age group i.e., the young, skilled migrants and international students ( King et al. 2016; Coulter et al., 2016; Finney, 2011). Migration later in life (circular or permanent) requires specific attention as adapting to an unfamiliar environment can be particularly stressful for the elderly ( Jang et al., 2020). Review studies considering the intersection of aging and migration are either country-specific, focused on the general ageing experiences, migration from developed to developing countries, or the social impact of late-life migration ( Georgeou et al., 2021, Tang & Zolnikov, 2021; Maleku et al., 2021; Wang & Lai, 2020). The mental health impact of conflict-induced forced migration has also been studied extensively with a particular focus on refugees and asylum seekers ( Virgincar et al., 2016). There have been some studies on the mental health and well-being of older adults otherwise at liberty to migrate. However, there is a lack of systematic review of such studies.

The 1998 United Nations Recommendations on Statistics of International Migration define ‘international migrant’ as a person who has changed their country of residence. Those migrating over the age of 65 are a significant number and would be close to 26 million worldwide ( Zaiceva, 2014). In Australia, Canada, and New Zealand, the number of older retired migrants is close to the number of working migrants ( Zaiceva, 2014). It is known that the likelihood of migration in later life reduces with age ( Holecki et al., 2020), however, an initial scope showed that very few studies have focussed on the mental health and well-being of older migrants above 65 years. The age criterion for the proposed systematic review is expanded to older adults aged 50 years and above.

The main objective of the planned systematic review is to analyse and summarise existing research (both qualitative and quantitative) on the impact of international migration later in life on the mental health of older adults. The review of studies will specifically focus on answering the following research questions. a)

What are the individual, social and political contexts in which people decide to migrate later in life?

The eligibility criteria for the included publications will be described based on the Population, Interest, context (PICo) framework ( Lockwood et al., 2015).

We will include original studies on later-life migrants (≥ 50 years). Although the most accepted definition of old age is the age at which people start receiving a pension (i.e., above the age of 60, depending on country location), the socio-cultural definition of old age differs from country to country (WHO 2002; Zittoun & Baucal, 2021). For this review, later life would mean 50 years and above.

The migration experiences of different categories of migrants including refugees, asylum seekers, and displaced people vary a lot and thus can have a different impact on health outcomes. Thus, this review focuses exclusively on migrants and has excluded studies on refugees, asylum seekers, and other undocumented migrants. We will also exclude studies that are not specifically related to later-life migration. Navigating migration in older life is known to be particularly difficult. Liu et al., 2020). Research indicates older age at migration and limited years in the host country are significantly associated with negative mental health consequences which get moderated over time with increased cultural adaptation ( Xiao et al., 2019). Negy et al., 2009 showed that retrospective memory of the migration experience declines after 5-years. The inclusion criteria for the length of stay of migrants in the destination country is thus set to ≤ 5 years. Studies in which the length of stay cannot be ascertained or is more than 5 years will be excluded.

Elderly migrants are more susceptible to mental health issues because of the loss of a familiar environment and difficulty making newer social connections ( Wang et al., 2022). All studies looking at the positive or negative impact of migration on the mental health and well-being of elderly migrants will be included.

Although internal migration can be equally challenging for older adults, for this review, studies focussing only on international migration/movement across international borders will be included. Studies related to intra-country/internal migration (rural to urban) will be excluded.

We will include all types of original studies that meet the above-mentioned inclusion criteria. Grey literature, reports of government and non-governmental organisations, editorial letters, conference papers, poster presentations, dissertations, expert opinions, letters to the editor, commentaries, and reviews will be excluded.

No restriction by the type of setting will be used.

All articles published from the date of origin of the database to 23 ^rd May 2022 will be included.

Original articles that are published in academic peer-reviewed journals will be included.

Studies published only in English will be included.

To make the search comprehensive, a search of the current literature using seven electronic databases will be performed. These include (1) PsycINFO (via Ovid); (2) Web of Science (via Ebsco); (3) PubMed; (4) Applied Social Sciences Index and Abstracts: ASSIA; (5) Age line (via Ebsco); (6) CINAHL (via Ebsco); and (7) Informit Search. Hand-searching of potentially relevant studies will be done through the reference lists of all included studies and the reference lists of previously published related systematic reviews.

The search strategy will be developed using the PICo framework ( Lockwood et al., 2015), combined with Medical Subject Headings (MESH) where applicable. Searches will be structured using a combination of keywords related to three main concepts; terms related to the study population such as “elderly”, “seniors”, (2) terms related to interest such as “mental health” or “mental issues”, and (3) terms related to context such as “migration”, “immigration”. The similarity of search terms will be ensured across databases to maintain consistency. The following are the search terms used in CINAHL VIA EBSCO without any limiters: (Grandparent OR grandparents OR grandmother OR grandmothers OR grandfathers OR grandfather OR geriatric* OR “senior citizens” OR “late-life” OR “later life” OR elderly OR “third age” OR “fourth age” OR retire* OR pensioners OR “Extended Family” OR “old aged” OR “older adults” OR “older adulthood”) AND (“mental health” OR “psychological health” OR “well being” OR wellbeing OR “Quality of life” OR “life satisfaction” OR coping OR resilience OR depression OR anxiety OR loneliness OR suicide OR suicidal) AND (migration OR immigration OR migrant? OR immigrant? OR “temporary visa” OR “temporary entrant” OR “documented migrants” OR “documented migrant” OR “documented immigrant?” OR “documented immigrants” OR “authorized immigrants” OR “authorized immigrant")

Search results will be imported to Endnote, and then exported to Covidence systematic review software and duplicates will be auto-removed. While Endnote is a paid reference management software, free alternatives such as ReadCube Papers can likewise be used. Zotero is likewise a free alternative to Covidence for systematic screening of literature. In the first stage of screening using Covidence, the first reviewer (PB) will screen the titles and abstracts of each study against the inclusion criteria and the second reviewer (HM) will review the decisions made. Any disagreements will be mutually resolved through discussion. Potentially eligible records will be marked for full screening. Those titles and abstracts that provide insufficient information to determine relevance, will also be subjected to full screening. Afterward, full texts of potentially eligible studies will be retrieved for full-text review and assessed for eligibility by two review authors (PB and HM). Hand-searching of the references of selected articles will be conducted for identifying potentially relevant studies. During the entire process, the eligibility of the studies will be negotiated by consensus.

A customised form will be used for data extraction. The following study characteristics will be extracted in a customised form: o

Details of authors

o

Aims/objectives/research questions

The data extraction form will be developed through consultation. All the authors will contribute to data extraction. NVivo QSR will be used to assist in data extraction. A flow chart showing details of studies included and excluded at each stage of the study selection process will be provided.

The thematic synthesis of the data (both qualitative and quantitative) will be performed using a hybrid approach incorporating two contrasting philosophical methods of reasoning i.e., a top-down, deductive, theoretical process, and a bottom-up, inductive, data-driven process. For the deductive method, a table of priori codes will be created using an adaptation of the social determinants of health (SDH) framework with intersectionality as the lens. For effectively addressing mental health issues, causal pathways can best be understood with the SDH using an intersectional lens.

Of all the frameworks used in health research – behavioural, cultural, structural, and social determinants of health – SDH is one of the most comprehensive frameworks as it takes into account a range of factors; social, economic, cultural, and political impinging upon the health of the person. WHO defines SDH as, “conditions in which people are born, grow, live, work, and age – conditions that together provide the freedom people need to live lives they value” (Commission on Social Determinants of Health, 2008, p. 26). SDH emphasizes the construction and impact of social structures and people’s relative positions in stratified hierarchies and power relationships and takes into consideration the interconnectedness of social, structural, and/or ecological factors that affect people’s health status ( Castañeda et al., 2015). There has been growing interest in the social determinant of health framework in public health research and non-profit agencies, ( Braveman et al., 2011), however, this framework has not been widely used in the field of immigration and health. An intersectional lens will be employed to understand the complexity and interconnectedness of various determinants.

Individual factors like age, gender, socioeconomic position, educational background, and financial stability which largely determine the welfare benefits one receives in the host country will be explored. An understanding of attitudes toward mental health, stigma, stereotypes, beliefs, and taboos related to mental illnesses is also important to understand the health-seeking behaviours of migrants in a new culture. This includes their relationship to the traditions and practices of the culture of origin.

Despite the WHO’s emphasis on the ‘Health in all Policies’ approach, the influence of upstream SDH on migrants’ health largely goes unexplored in the migrant literature ( WHO, 2014; Castañeda et al., 2015). For this review, attention would be given to the influence of upstream SDH including policies related to healthcare, welfare, insurance, and migration. Additionally, the economic policies of the host country, the differences in the socio-cultural context, and their impact on the mental health of migrants will also be explored.

Older migrants in most cases tend to stay with their adult children upon arriving in the host country ( Liou & Shenk, 2016). Thus, family dynamics (conflict between intimate relationships), interactions with family members including spouse, children, grandchildren, and dependence on family members often lead to specific psychosocial stressors ( Liou & Shenk, 2016). Specific attention will be given to the role of interpersonal relationships, formal and informal social networks, and social support systems in affecting the mental health and well-being of migrants. Migrants’ interactions with healthcare institutions, and other facilities like aged care, voluntary organizations working for migrants, and religious organisations will also be reported.

The priori set of codes will be supplemented with the codes emerging through the inductive analysis of the articles. To improve intercoder reliability, coding will be regularly reviewed by all three reviewers, and disparities and discrepancies (if any) will be addressed with consultation.

A narrative synthesis will summarize and explain the characteristics and findings of the studies. Data will not be quantitatively synthesised. Quality appraisal of the included studies is a mandatory requirement of systematic reviews reported according to PRISMA guidelines. The methodological quality (or risk of bias) of individual studies will be appraised using the Mixed Method Appraisal Tool (MMAT) as it is highly useful in the appraisal of a range of study designs included in the mixed methods integrative systematic review ( Hong et al., 2018; Pluye, 2015). To achieve consistency, the reviewers will develop a common understanding of the appraisal tool through discussions.

One of the main strengths of the protocol is its use of a comprehensive search strategy and a range of databases covering areas of migration, mental health, and ageing. No limitation has been applied in terms of the year of publication. It would be difficult to avoid publication bias because of the exclusion of grey literature and studies published in languages other than English. There is also a possibility of exclusion of some data of interest because of the exclusion of studies having a heterogenous population including undocumented migrants, refugees, asylum seekers, and displaced people, and studies not focussing specifically on later-life migration are also excluded.

Searching and screening for relevant studies is expected to be completed in January 2023.