John Moriarty

Bereavement After Informal Caregiving: Assessing Mental Health Burden Using Linked Population Data

OBJECTIVES We compared the mental health risk to unpaid caregivers bereaved of a care recipient with the risk to persons otherwise bereaved and to nonbereaved caregivers. METHODS We linked prescription records for antidepressant and anxiolytic drugs to characteristics and life-event data of members of the Northern Ireland Longitudinal Study (n = 317 264). Using a case-control design, we fitted logistic regression models, stratified by age, to model relative likelihood of mental health problems, using the proxy measures of mental health-related prescription. RESULTS Both caregivers and bereaved individuals were estimated to be at between 20% and 50% greater risk for mental health problems than noncaregivers in similar circumstances (for bereaved working-age caregivers, odds ratio = 1.41; 95% confidence interval = 1.27, 1.56). For older people, there was no evidence of additional risk to bereaved caregivers, though there was for working-age people. Older people appeared to recover more quickly from caregiver bereavement. CONCLUSIONS Caregivers were at risk for mental ill health while providing care and after the death of the care recipient. Targeted caregiver support needs to extend beyond the life of the care recipient.

Effects of peer network interactions on adolescent cannabis use

Purpose – The purpose of this paper is to capitalise on three waves of longitudinal data from a cohort of 4,351 secondary school pupils to examine the effects on individuals’ cannabis use uptake of both peer cannabis use and position within a peer network. Design/methodology/approach – Both cross-sectional and individual fixed effects models are used to estimate the effect on cannabis use of nominated friends’ cannabis use, of reciprocity and transitivity of nominations across the friendship cluster, and of interactions between these nominated friends. Post hoc analyses parsed the behaviour of reciprocating and non-reciprocating friends. Findings – Cannabis use varied depending on the stability of friendship network and the degree of reciprocity and interconnectedness within the group. Behavioural influence was strong, but interaction effects were observed between the prevalence of cannabis use among friends, the structure of the friendship group and ego’s proximity to group members. These interactions de...

Peer Effects in Adolescent Cannabis Use: It's the Friends, Stupid

This paper examines peer effects in adolescent cannabis use from several different reference groups, exploiting survey data that have many desirable properties and have not previously been used for this purpose. Treating the school grade as the reference group, and using both neighbourhood fixed effects and IV for identification, we find evidence of large, positive, and statistically significant peer effects. Treating nominated friends as the reference group, and using both school fixed effects and IV for identification, we again find evidence of large, positive, and generally statistically significant peer effects. Our preferred IV approach exploits information about friends of friends – ‘friends once removed’, who are not themselves friends – to instrument for friends’ cannabis use. Finally, we examine whether the cannabis use of schoolmates who are not nominated as friends – ‘non-friends’ – influences own cannabis use. Once again using neighbourhood fixed effects and IV for identification, the evidence suggests zero impact. In our data, schoolmates who are not also friends have no influence on adolescent cannabis use.

Caregiving, volunteering or both? Comparing effects on health and mortality using census-based records from almost 250,000 people aged 65 and over.

Background the health impacts of caregiving and volunteering are rarely studied concurrently, despite the potential for both synergies and conflicts. This population-based study examines the association of these activities on health and subsequent mortality. Method a census-based record-linkage study of 244,429 people aged 65 and over, with cohort characteristics, caregiving and volunteering status, and presence of chronic health conditions derived from the Census returns. Mortality risk was assessed over the following 45 months with adjustment for baseline characteristics. Results caregivers and volunteers were individually more mobile than those undertaking neither activity; caregivers who also volunteered were more mobile than those who did not volunteer, but no less likely to suffer from poor mental health. Both caregiving and volunteering were separately associated with reduced mortality risk (HR = 0.74: 95% confidence intervals (CIs) = 0.71, 0.77 and HR = 0.76: 0.73, 0.81, respectively); the lowest mortality was found amongst light caregivers who also volunteered (HR = 0.53: 95% CIs = 0.45, 0.62), compared to those engaged in neither. There was no evidence of a multiplicative effect of caregiving and volunteering at more intense levels of caregiving. Conclusion there is a large overlap in caregiving and volunteering activities with complex associations with health status. There is some evidence that combining caregiving and volunteering activities, for those involved in less intense levels of caregiving, maybe associated with lower mortality risk than associated with either activity alone. Further research is needed to understand which aspects of caregiving and volunteering are best and for whom and in which circumstances.

Volunteering and mortality risk: A partner-controlled quasi-experimental design

Background The consensus that volunteering is associated with a lower mortality risk is derived from a body of observational studies and therefore vulnerable to uncontrolled or residual confounding. This potential limitation is likely to be particularly problematic for volunteers who, by definition, are self-selected and known to be significantly different from non-volunteers across a range of factors associated with better survival. Methods This is a census-based record-linkage study of 308 733 married couples aged 25 and over, including 100 571 volunteers, with mortality follow-up for 33 months. We used a standard Cox model to examine whether mortality risk in the partners of volunteers was influenced by partner volunteering status-something expected if the effects of volunteering on mortality risk were due to shared household or behavioural characteristics. Results Volunteers were general more affluent, better educated and more religious than their non-volunteering peers; they also had a lower mortality risk [hazard ratio (HR)adj = 0.78: 95% confidence interval (CI) = 0.71, 0.85 for males and HRadj = 0.77: 95% CI = 0.68, 0.88 for females]. However, amongst cohort members who were not volunteers, having a partner who was a volunteer was not associated with a mortality advantage (HRadj = 1.01: 95% CI = 0.92, 1.11 for men and HRadj = 1.00: 95% CI = 0.88, 1.13 women). Conclusions This study provides further evidence that the lower mortality associated with volunteering is unlikely to be due to health selection or to residual confounding arising from unmeasured selection effects within households. It therefore increases the plausibility of a direct causal effect.

Starting slow: The effects of response-switching frequency on patterns of cardiovascular reactivity

Research findings suggest that switching between competing response sets can be resource demanding. The current study focused on concurrent health-relevant physiological effects of task switching by assessing cardiovascular response at varying levels of switch frequency. The participants performed a response-switching task at three different levels of response set switching frequency (low, medium and high) while measurements of blood pressure and heart rate were taken. One group was exposed to response-switching frequency conditions in the order low → medium → high, while the other group was exposed to the same task conditions in the reverse order (i.e. high → medium → low). The results showed that the participants in the low → medium → high switch frequency group recovered faster from initially heightened systolic blood pressure when compared with participants in the high → medium → low group. It is concluded that the results point to a physiological “carry over” effect associated with beginning a task at rapid response switching frequency levels, and suggest the importance of habituation to task demands as a means of offsetting potentially unhealthy levels of reactivity. Implications for modern work environments are discussed.