Introduction and background

Providing informal care for a frail older relative or friend is an increasingly common experience for individuals, primarily as a result of increasing longevity (Pickard, Reference Pickard2015; Broese van Groenou and De Boer, Reference Broese van Groenou and De Boer2016). Previous research has shown that mid-life (i.e. between ages 45 and 55) is the age at which one's risk of providing informal care peaks across the lifecourse, with implications for individuals' health and economic participation (Dykstra and Komter, Reference Dykstra and Komter2012; Evandrou et al., Reference Evandrou, Falkingham, Robards, Vlachantoni and McGowan2015; Bardoel and Drago, Reference Bardoel and Drago2016; Hanson and Starr, Reference Hanson and Starr2017). Since the inclusion of a question regarding informal care provision in the UK Census 2001, repeated in 2011, and the increased availability of longitudinal data internationally such as the Survey of Health, Ageing and Retirement in Europe (SHARE), a substantial body of literature has examined patterns of informal care provision across different age groups, as well as the more detailed nature of the care-giving activity such as the number of hours dedicated to care, the relationship between the person caring and the person cared for, and whether they live in the same household (Dahlberg et al., Reference Dahlberg, Demack and Bambra2007; Norman and Purdam, Reference Norman and Purdam2013; Robards et al., Reference Robards, Vlachantoni, Evandrou and Falkingham2015).

A more limited body of work has focused on the relationship between care provision and the health of the carer, producing mixed results depending on whether the study is cross-sectional or longitudinal (Vlachantoni et al., Reference Vlachantoni, Evandrou, Falkingham and Robards2013). This paper analyses prospectively collected data from a UK cohort study to describe trajectories of care provision in mid-life for men and women. It then investigates how different care trajectories are associated with carers' health status measured in two different ways: report of depression, reflecting mental health; and self-reported general health, reflecting overall health status. The findings address an important gap in the literature in two ways. Firstly, previous literature on caring trajectories and their impact on the carers' health has tended to focus on broad age groups covering the whole adult population; here the research explicitly focuses on the experience of mid-life individuals who are at the highest risk of ‘juggling’ the demand for care provision towards older relatives with caring for younger relatives (Vlachantoni et al., Reference Vlachantoni, Evandrou, Falkingham and Gómez-León2020). Secondly, the study of caring patterns during mid-life has implications for other life domains for individuals at this important stage of the lifecourse, including their continued economic activity patterns as they approach retirement and their relationships with both younger and older generations of relatives (Evandrou et al., Reference Evandrou, Falkingham, Gómez-León and Vlachantoni2018; Gómez-León et al., Reference Gómez-León, Evandrou, Falkingham and Vlachantoni2019).

This paper is the first, to our knowledge, to use prospectively collected cohort data to map the caring trajectories of individuals across mid-life in the UK, and to assess the impact of such trajectories on the individuals' health status. The analysis allows us to take into account a range of factors which have been found to be important in previous research in this area, such as the carer's gender and the number of hours of care provided during a week, reflecting the intensity of the care provided.

Review of the literature

To provide the broader context for this research, it is first important to outline the social care landscape within which our analysis is located. In the UK, individuals who need social support can receive such support from a range of sources, including informal sources (e.g. family members), formal state sources (e.g. local government services) or formal paid sources (e.g. private sector). However, as in many other countries, the majority of care is provided by family, particularly by female partners or daughters over most of the lifecourse (Maplethorpe et al., Reference Maplethorpe, Darton and Wittenberg2015), and male spouses in later life (Robards et al., Reference Robards, Vlachantoni, Evandrou and Falkingham2015). There are some differences in the way formal social care is organised across the countries of the UK. Within England, where the majority of the UK population resides, local authorities are legally responsible for adult social care, and both carers and care recipients are assessed before any support can be provided in the form of a caring allowance and/or support with day-to-day activities in the home of the care recipient. For individuals who are middle-aged themselves, and are providing care to older relatives, the receipt of support from the state often interacts with their economic activity patterns (and earnings). Existing research has aimed to disentangle the interactions between economically active individuals' work and care-giving, indicating, for instance, that many female carers remain ‘trapped’ in low-paid jobs in order to combine their paid work with their caring obligations, whilst at the same time receiving some support from the state (Carmichael and Charles, Reference Carmichael and Charles2003; Buckner and Yeandle, Reference Buckner and Yeandle2006).

Existing research on the impact of care provision on the carer's health has shown mixed results, depending on the nature of the data analysed. From an empirical viewpoint, cross-sectional research has broadly shown that care provision is associated with poor health for the carer, although there exist differences depending on the specific health outcome measured (Young et al., Reference Young, Grundy and Kalogirou2005; Brown and Brown, Reference Brown and Brown2014), and the health and demographic characteristics of the person cared for (O'Reilly et al., Reference O'Reilly, Connolly, Rosato and Patterson2008; Capistrant et al., Reference Capistrant, Moon, Berkman and Glymour2012). For example, Doran et al. (Reference Doran, Drever, Whitehead and Duncan2003) analysed data from the 2001 UK Census and found that individuals who did not provide any care were somewhat more likely to report good health compared to individuals who were providing care. However, research by O'Reilly et al. (Reference O'Reilly, Connolly, Rosato and Patterson2008) using the 2001 Northern Ireland Census introduced the intensity of care provided in the equation and showed that although overall carers were indeed less likely than non-carers to report a limiting long-term illness (LLTI), it was those who provided more than 50 hours of care per week who showed the worst health outcomes. Also using the 2001 UK Census and focusing on couples aged 65 and over where at least one of the spouses reported a LLTI, Young et al. (Reference Young, Grundy and Kalogirou2005) found that individuals who provided more intense care (i.e. more than 20 hours per week) were more likely to report poor health than those who provided less intense care. Along similar lines, Harris et al. (Reference Harris, D'Angelo, Syddall, Linaker, Cooper and Walker-Bone2020) used data from the Health and Employment After Fifty study, a cross-sectional sample of individuals aged 50–64 recruited from general practices, to show that men and women caring for more than 20 hours per week were more likely to report health problems such as musculoskeletal pain, poor or fair self-rated health, depression and sleep problems.

By contrast, longitudinal analysis from the UK and elsewhere has examined the impact of care trajectories on the carers' wellbeing over time and has either shown care provision to have no negative effect on the carer's health (see e.g. Rahrig Jenkins et al., Reference Rahrig Jenkins, Kabeto and Langa2009; Tooth and Mishra, Reference Tooth and Mishra2014) or it has shown a slightly lower mortality risk among carers compared to non-carers once a range of demographic and socio-economic characteristics are controlled for. For example, O'Reilly et al. (Reference O'Reilly, Connolly, Rosato and Patterson2008) used linked data from the 2001 Northern Ireland Census to examine the health of informal carers and their mortality risk four years later and found that care-givers had a lower mortality risk than non-care-givers, but such risk increased among care-givers as the number of hours of care provided increased. Fredman et al. (Reference Fredman, Cauley, Hochberg, Ensrud and Doros2010) analysed data between 1999 and 2007 on care-givers and non-care-givers in the United States of America; they also found that overall care-givers face a lower mortality risk than non-care-givers, although care-givers are more likely to report specific types of conditions such as stress. By contrast, Lawton et al. (Reference Lawton, Moss, Hoffman and Perkinson2000) analysed data over a four-year period for more than 600 women aged 65 and over, and found that women who had provided care for at least 12 months were more likely to report poor physical and mental health compared to those who had not provided any care or care of a shorter duration over the four years. Other recent research has also found adverse effects on informal carers, e.g. using data from three waves of the Korean Longitudinal Study of Aging, Kyung Do et al. (Reference Kyung Do, Norton, Stearns and Van Houtven2014) showed that providing informal care to one's parents-in-law has significant adverse health effects on daughters-in-law along multiple health dimensions, such as the report of pain during daily activities, worsening self-reported general health and regular prescription drug use. Finally, Barbosa et al. (Reference Barbosa, Voss and Delerue Matos2020) used data from the SHARE to show that co-residential carers aged 50+ in Portugal at Wave 4 were 60 per cent more likely than non-carers to report depressive symptoms at Wave 6.

Research examining the health impact of movements into and out of the caring role has also offered valuable empirical insights, highlighting the role of the relationship between the care provider and the care recipient in this respect. Ross et al. (Reference Ross, Lloyd, Weinhardt and Cheshire2008) investigated the impact of moving into or out of caring between 2004 and 2006, and found that there were no differences in the health of carers between the two time-points. However, those who moved out of caring between 2004 and 2006 were slightly more likely to report poor health in 2006. Kaufman et al. (Reference Kaufman, Lee, Vaughon, Unuigbe and Gallo2019) analysed data from four waves of the Health and Retirement Study and also found elevated symptoms of depression among exit care-givers, as well as among new and continuing care-givers, compared to non-carers. Exploring the impact of juggling multiple roles simultaneously (e.g. carer, parent, paid worker), Glaser et al. (Reference Glaser, Evandrou and Tomassini2005) analysed data from the 1988–1989 and 1994 longitudinal Retirement Survey and found that occupying multiple roles between 1988 and 1989 resulted in poorer health outcomes in 1994. The analysis of 2004/5 and 2006/7 data from the English Longitudinal Study of Ageing showed that compared to non-care-giving, entry into spousal or child care-giving was associated with a decline in the carer's quality of life (although entry into care-giving for other kin relations increased life satisfaction and lowered depressive symptoms), while exiting care-giving was related to increased depression in both spousal/child carers and carers of other kin relations (Rafnsson et al., Reference Rafnsson, Shankar and Steptoe2017). Along the same lines, more recent cross-national analysis by Uccheddu et al. (Reference Uccheddu, Gauthier, Steverink and Emery2019), focusing on spousal care provision over five waves of the SHARE, showed that although transitions into care-giving have a detrimental effect on the carer's health, nevertheless transitions out of care-giving, in most cases, do not have beneficial effects on the carer's health.

Taking into account the intensity of the care provided has also been shown to be an important dimension when exploring the impact of care-giving over time. Vlachantoni et al. (Reference Vlachantoni, Robards, Evandrou and Falkingham2016) analysed data from the Office for National Statistics Longitudinal Study, linking the 2001 and 2011 UK Census respondents for England and Wales, and found that individuals who provided care in 2011 (regardless of their caring status ten years earlier) were less likely to report poor health in 2011 than those who had not provided care in 2001 and 2011; while those providing more than 20 hours of care per week in 2001 who were not caring in 2011 faced a higher risk of poor health than non-carers at the two time-points. Finally, using a shorter time-frame with data on women aged between 21 and 53 years between 2004 and 2009 from the China Health and Nutrition Survey, Lu et al. (Reference Lu, Dallal, He, Juon, Wang and Lee2019) found that ‘rising-to-high-intense’ and ‘stable-low-intense’ care-givers of parents/parents-in-law faced a higher risk of metabolic syndrome compared to non-care-givers.

The theoretical framework for the analysis in this paper draws on the care-giving and stress model (Pearlin et al., Reference Pearlin, Mullan, Semple and Skaff1990) and the earlier transactional model of stress and care (Lazarus and Folkman, Reference Lazarus and Folkman1984). These models point to the potentially adverse effect of care-giving-related factors such as the nature, duration and intensity of care provided, on the carer's health over time, and have been utilised in previous research examining the impact of care-giving on the carer's health and mortality outcomes (see e.g. Fredman et al., Reference Fredman, Cauley, Hochberg, Ensrud and Doros2010). Two possible outcomes to this process have been identified in the literature. The ‘wear-and-tear’ hypothesis indicates that there is an accumulation of demands and stress, measured with a variety of indicators, which results in the continuous deterioration of the carer's wellbeing and coping resources. By contrast, the ‘adaptation’ hypothesis points to the gradual adjustment on the carer's part to the demands of the care-giving process, with a less adverse impact on their own health and wellbeing. Our paper considers key care-giving-related factors such as the intensity of care provided over three points in time and takes into account two distinct indicators of wellbeing on the part of the carer (self-reported health, depression). The ‘wear-and-tear’ hypothesis would predict worse self-reported health and a higher risk of depression for all carers, compared to the baseline; while the ‘adaptation’ hypothesis would predict a decline in the carer's wellbeing earlier in the care-giving process (i.e. when starting care-giving) compared to carers who have provided care at more than one point in time.

Considering the key empirical findings of existing research and our theoretically based expectations, it is possible that mid-life carers are overall more likely to report poor health compared to non-carers. Among those who provide care, the intensity of the care provided is likely to be pivotal, with those who provide less intense care during a week expected to be less likely to report poor health outcomes, taking into account their health status at baseline. However, some of the empirical evidence behind such an expectation is based on research using linked census data where observations are a decade apart, with no knowledge of care provision patterns between the time-points under study; having more detailed information in the intervening periods could yield different results. The analysis in this paper allows us to consider a number of control variables utilised in previous research, such as the carer's marital status (Vlachantoni et al., Reference Vlachantoni, Robards, Evandrou and Falkingham2016; Lu et al., Reference Lu, Dallal, He, Juon, Wang and Lee2019) and their educational qualifications (Kyung Do et al., Reference Kyung Do, Norton, Stearns and Van Houtven2014), following a cohort of individuals born in 1958 through mid-life.

Research questions

This paper employs three waves from a British cohort study, the National Child Development Study (NCDS), in order to address the following research questions:

1. (1) What is the pattern of caring trajectories (i.e. in and out of care provision) during mid-life?

2. (2) Among male and female carers, how does the intensity of caring vary between ages 46 and 55?

3. (3) How are different caring trajectories between ages 46 and 55 associated with the carer's health outcomes at age 55, and what are the gender differences in this respect?

The focus of the paper is on mid-life carers (aged between 46 and 55) who provide care to their parents or parents-in-law. As such, this paper makes an original contribution to the body of work examining adult children's care provision towards their parents from a dynamic, lifecourse perspective (Alessie et al., Reference Alessie, Angelini and Pasini2014; Evandrou et al., Reference Evandrou, Falkingham, Gómez-León and Vlachantoni2018). Two health outcomes are focused upon, reflecting different aspects of an individual's health status: self-reported health and diagnosis of depression.

Empirical strategy

Data and analytical sample

To date there is relatively little empirical research that has involved analysis of caring trajectories. Keating et al. (Reference Keating, Eales, Funk, Fast and Min2019) hypothesised three family care trajectories which they labelled generational, career and serial. Their subsequent empirical analysis using Statistical Canada's General Social Survey on Caregiving and Care Receiving operationalised four components of care trajectories: age of onset of the first care episode; number of episodes of care in the individual's lifecourse; total duration of all episodes of care; and the extent to which episodes overlapped one another (Fast et al., Reference Fast, Keating, Eales, Kim and Lee2021). Latent Profile Analysis was then used to create a set of caring trajectories using this retrospectively collected data. This study differs in its approach, utilising prospectively collected cohort data.

The paper analyses data from three waves (Waves 7, 8 and 9) of the NCDS, a cohort study of more than 17,000 children born in a single week in March 1958 in Britain who have been followed up through the course of their lives (University of London, Institute of Education and Centre for Longitudinal Studies, 2015). The information employed in this study was collected when the cohort members were aged 46, 50 and 55, respectively. From a total sample of 7,469 individuals interviewed at least once between the ages of 46 and 55, the analysis here is restricted to those individuals who are ‘at risk’ of providing parental care, i.e. who had at least one living parent/parent-in-law at any of the three points in time, resulting in a final analytical sample of 7,013 individuals.

Table 1 shows the number of individuals (and sample proportion) who were at risk of caring for their parents/parents-in-law. Most of the cohort members were at risk of providing help to parents/parents-in-law at all three observation points, i.e. at ages 46, 50 and 55. Approximately 13 and 19 per cent of men and women, respectively, faced an intermittent risk of caring, meaning that they were at risk in one or two waves; this group includes those cohort members whose parent died during the period of study; as we are interested in caring trajectories, it was felt important to retain these individuals in the analytical sample so as to capture those who cease caring during mid-life due to bereavement. The sample may also include those cohort members who gain a parent-in-law during mid-life through marriage and thus become at risk of providing care. Just 5 per cent of male and 7 per cent of female cohort members did not have a surviving parent or parent-in-law at any observation point and so were excluded from the final analytical sample.

Table 1. Respondents at risk of caring for a parent or parent-in-law in Waves 7, 8 and 9, by gender (%)

Note: 1. Individuals with at least one parent or a parent-in-law alive.

Source: Authors' analysis of the National Child Development Study.

As is the case with most longitudinal studies, the NCDS is affected by attrition. Previous analysis of attrition and missing data in this dataset has found that attrition is higher among male respondents, among individuals with a lower socio-economic status and those with lower educational qualifications (Hawkes and Plewis, Reference Hawkes and Plewis2006). The analytical sample used here may also be affected by differential mortality amongst the respondents' older parents (Office for National Statistics, 2019). Given this, gender, socio-economic status and education were all included as control variables in the analysis.

Definition of key variables

Caring trajectories and caring intensity

The NCDS collected a range of information on the provision of informal care which allows us to derive two measures of care-giving: (a) intensity of care-giving and (b) care-giving trajectories.

The following question was used to construct a variable on ‘Caring for parents/parents-in-law’ at ages 46, 50 and 55, the question wording being the same in each of the three waves analysed here:

Do you regularly or frequently do any of the things listed for your parents or parents-in-law? Response: Please select Yes or No for each activity listed below:

Dressing, eating, bathing, washing, ironing, cleaning, cooking, financial assistance, shopping, transportation, gardening and others, none of these.

For those who mentioned they did provide care with at least one of these tasks, the survey then included information on how much time they spent providing care. This question was asked of respondents who provide care with any of the aforementioned tasks:

How many hours do you spend doing this/these things for [parents or parents-in-law] in a typical week?

Although the question was consistent between the three waves, the response categories differed slightly. In Waves 8 and 9, the response is continuous, ranging from 0 to 168 hours. However, in Wave 7, the response includes the following categories: not caring, 0–9 hours, 10–19 hours, 20–34 hours, 35–49 hours, 50–99 hours, 100+ hours and it varies/other.

Responses were therefore combined to derive a new variable called ‘Caring intensity’ which showed the intensity of care provision in four categories: not caring, 9 or fewer hours a week, 10–19 hours a week and 20+ hours a week. This categorisation has been applied by other published research on the same topic (e.g. Evandrou et al., Reference Evandrou, Falkingham, Gómez-León and Vlachantoni2018).

In order to examine the care-giving role from a dynamic perspective, a ‘care-giving trajectories’ variable was then derived that captures changes in the respondents' caring status between ages 46, 50 and 55 (Table 2). Three of the four categories in this variable (categories 1, 2 and 4) have been used in previous studies (Kaufman et al., Reference Kaufman, Lee, Vaughon, Unuigbe and Gallo2019; Hurh et al., Reference Hurh, Youn, Park, Park and Jang2021):

1. (1) Repeat carers (caring at all three points of observation).

2. (2) New carers (those who started caring in the second or third point of observation).

3. (3) Sporadic or intermittent carers (first and third waves, or only second wave).

4. (4) Stopped caring (those who stopped caring at second or third wave).

Table 2. Deriving caring trajectories: the provision of care at ages 46, 50 and 55

Notes: Total N = 7,013. ‘Repeat’ carers refers to those caring at the three points of observation (ages 46, 55 and 55).

Source: Authors' analysis of the National Child Development Study.

We use the term ‘repeat carers’ to describe respondents who were providing care at all three data collection points, however, it is not possible to ascertain whether respondents were also providing care in the intervening periods. Thus, we are cognisant of the limitations of this concept, and careful in the interpretation of the findings (see also Robards et al., Reference Robards, Vlachantoni, Evandrou and Falkingham2015).

Outcome variables

The two outcome variables were the report of depression and poor self-reported health. For the former, the question was slightly different between the waves. In Wave 7, respondents were asked to report any type of long-standing illness, disability or infirmity, which included depression as one of the responses. In Wave 9, depression was included in the responses as a type of emotional condition.

For self-reported health, the question was:

Please think back over the last 12 months about how your health has been. Compared to people of your own age, would you say that your health has, on the whole, been: excellent, good, fair, poor or very poor?

Control variables

The variable for educational qualifications distinguished between four categories: up to low O-level, high O-level, A-level and sub-degree, and degree or higher. The categories for the respondents' living arrangements included: living alone, living with partner only, living with partner and others, and living with others only. Two variables were used regarding relationships: on one hand, we included a variable recoded into three categories (married/civil partnership, single never married and divorced/separated/widowed); on the other hand, we included a variable to account for the possibility of becoming widowed along the period of observation, between the ages of 46 and 55.

To account for possible reverse causality deriving from the fact that poor health may influence the provision of support, we also included the carer's health status at baseline, an approach that has been used in previous studies to account for reverse causality (Johnson, Reference Johnson2005; Baker and Silverstein, Reference Baker and Silverstein2008; Tosi and Grundy, Reference Tosi and Grundy2018; Arpino and Gómez-León, Reference Arpino and Gómez-León2020). This allows us to account for the initial health status of the care-giver and its potential influence on providing care to others.