Table of Contents
Examine populace
We used knowledge from members of the English Longitudinal Research of Ageing (ELSA), a longitudinal cohort that recruited a agent sample of grown ups aged 50 years and more mature dwelling in private homes in England, as specific in other places [12]. The 1st wave of info assortment took location on March 1, 2002, with subsequent longitudinal assessments each individual 2 decades (wave 2 to wave 9) to measure variations in the wellness, economic and social conditions making use of confront-to-facial area interviews and self-administered questionnaires, and more nurse visits each 4 several years. The primary sample centered on Wellbeing Study for England (HSE) bundled 11,391 participants, and there were even more refreshment samples dependent on HSE at many waves (waves 3, 4, 6, 7 and 9) with different age requirements to suitable for the age profile as the original sample aged. As specific way of life variables this kind of as using tobacco and bodily action may possibly have altered over a very long interval of time (e.g., a ten years), the latest research utilised the most recent information predated the COVID-19 pandemic (wave 9, 2018–19), and two waves of the ELSA COVID-19 substudy (COVID wave 1 and wave 2, collected in June/July and November/December 2020 94% longitudinal reaction rate). Ethical approval was received from the Countrywide Investigation and Ethics Committee.
Analyses of this review are centered on data from individuals who participated in both of those COVID-19 surveys with readily available details in wave 9 study. In the two COVID-19 waves, contributors have been questioned about the self-isolation (outlined as not leaving household for any purpose) and stay-at-dwelling (described as only leaving home for very minimal applications) situations in April 2020 (early-phase of the outbreak), June/July and November/December 2020 (middle to late stage of the pandemic). The 1st and second national lockdown was enforced during the study period [13], and all those aged ≥70 decades were being considered clinically susceptible and instructed by the British isles Govt to stay at home and shield [14]. Contributors (381, 6.8%) who ended up not in self-isolation and did not continue to be at dwelling at any of the a few time details all through the time period were being excluded.
Socioeconomic qualities
Socioeconomic deprivation was characterised by particular person variables this kind of as money, wealth, and schooling, and by team-level aspect these kinds of as the Index of A number of Deprivation (IMD). Education level was classified as small (down below secondary), middle and higher (college or earlier mentioned), according to the Global Common Classification of Education [15]. Income was calculated from paid function, state benefits, pensions and belongings [12]. Wealth was derived from internet economic wealth that is gross fiscal prosperity (e.g., home, belongings, housing, investments, personal savings) minus money personal debt [12]. The IMD, encompassing domains this sort of as criminal offense, instruction, employment, overall health, housing, money, and dwelling environment, served as the formal measure of relative deprivation in England, representing the socio-financial position of people and communities [16, 17]. These factors ended up then classified into low (most affordable quintile), intermediate (quintiles 2 to 4), and high (best quintile) teams to characterize socioeconomic disparities across various degrees. In the major analyses, deprivation characterized by IMD was noted, which presented a comprehensive assessment of numerous socioeconomic attributes. Person socioeconomic elements, these kinds of as profits and training, had been made use of in the sensitivity analyses.
Healthier existence
We described a composite healthy life style rating such as 7 modifiable healthier lifestyle things centered on previous proof and United kingdom countrywide health and fitness service tips [7, 18,19,20]: BMI, smoking status, alcohol intake, bodily exercise, sedentary time, sleep duration, and fruit and vegetable ingestion. If available, we applied United kingdom countrywide pointers to crank out nutritious and unhealthy categories for every single life-style component [18]. 1 position was assigned for each and every harmful way of life class, like harmful physique weight (BMI < 18.5 or ≥25), current smoker, high alcohol intake (daily or almost daily), moderate or vigorous physical activity less than once per week, <7 or>9 h of snooze for every day, ≥7 h of sedentary time for each working day, and <5 portions of fruit and vegetable per day. Individuals’ scores were summed to create an unweighted score, and then classed as favorable (score 0–1), intermediate (score 2–3), or unfavorable (score 4–7) lifestyle category. Detailed definition of lifestyle category is provided in Supplementary Table 1. Distributions of the lifestyle score and lifestyle categories are shown in Supplementary Table 2.
Mental health outcomes
The mental health outcomes in this analysis were depressive symptoms, anxiety and personal well-being. Depressive symptoms were measured by an abbreviated eight-item version of the validated Center for Epidemiologic Studies Depression Scale (CES-D 8) [21]. A score of ≥4 was used to define participants of elevated depressive symptoms [22]. Anxiety was measured by the seven-item Generalized Anxiety Disorder (GAD-7) scale [23], using a threshold score of ten to define clinically significant symptoms [24]. Although the results do not necessarily represent clinical diagnoses, the CES-D and GAD are validated scales that used in large-scale population-based studies to measure symptoms of depression and anxiety [21, 23]. Personal well-being was assessed by the four-item Office for National Statistics (ONS) well-being (ONS-4) scale that capture three types of well-being: evaluative, eudemonic and affective experience [25]. A score of ≤4 was used to define participants of low personal well-being [25].
Covariates
Models were adjusted for a series of pre-pandemic covariates measured at baseline (wave 9), including age, sex, ethnicity, marital status, employment, disability, education, income, wealth, comorbidities and related conditions (chronic lung disease, asthma, arthritis, osteoporosis, cancer, Parkinson’s disease, dementia, hypertension, diabetes), and pre-pandemic mental health conditions (including history of psychiatric disorders, anxiety measured by ONS anxiety scale, depressive symptoms, and personal well-being) where applicable. In the sensitivity analyses, we additionally adjusted for pre-pandemic loneliness and social isolation that are risk factors for mental health outcomes and are anticipated direct consequences of pandemic and associated social and physical distancing. Loneliness was measured by the UCLA 3-item Loneliness Scale [26], and social isolation was measured by a composite score as in previous ELSA studies [27], in which one point was allocated for each of the following: not being married or cohabiting having less than monthly contact with each child, other members of the family, and friends (one point for each) and not being a member of organizations, such as religious groups or social groups.
Statistical analysis
We assess the associations between lifestyle factors, socioeconomic deprivation, and subsequent mental health conditions using Cox proportional hazards model, with study wave as the timescale that was adjusted for covariates.
Proportional hazard assumptions were checked based on Schoenfeld residuals and were satisfied. First, we separately assessed the association of composite lifestyle score (0–7 continuous variable) and lifestyle category (favorable, intermediate, and unfavorable) with mental health conditions, with adjusted for the above covariates and additionally for socioeconomic characteristics (education, income, and wealth). Second, we examined whether socioeconomic deprivation modified the association of lifestyle factors and mental health conditions. Multiplicative interactions between lifestyle category and socioeconomic deprivation characterized by group-level factor (IMD) were tested, with P values reported. We quantified the association between lifestyle category and mental health conditions across groups of socioeconomic deprivation, with the favorable lifestyle category as the reference group. We also estimated the combined effect of lifestyle and socioeconomic deprivation using nine ordinal categories, with participants in the least deprived group who were in the favorable lifestyle category as the reference group. The hazard ratio (HR) for trend per one increment change in lifestyle category was calculated. All models were adjusted for confounders including age, sex, ethnicity, marital status, employment, disability, comorbidities and related conditions. To account for potential reverse causality, pre-pandemic mental health was also adjusted, including history of psychiatric disorders, symptoms of depression and anxiety, and personal well-being.
Several sensitivity analyses were conducted to assess the robustness of the main analyses. First, in addition to the IMD as the primary socioeconomic characteristics, individual-level factors including education, income, and wealth were used to examine the contribution of socioeconomic deprivation. Second, we assessed the association between individual lifestyle factors (e.g., past or never smoker vs current smoker) and mental health conditions. Third, we run analyses after excluding participants with history of mental disorders. Forth, we additionally adjusted for pre-pandemic level of loneliness and social isolation that may be associated with both exposures and outcomes or mediate the association between lifestyle and mental health conditions during the COVID-19 pandemic. Finally,
All analyses were performed using SAS version 9.4 (SAS Institute) and R version 4.2.2 (R Foundation), and all statistical tests were two-sided, with p < 0.05 considered significant.