Latent variable model for suicide risk in relation to social capital and socio-economic status

There is little evidence on the association between suicide outcomes (ideation, attempts, self-harm) and social capital. This
paper investigates such associations using a structural equation model based on health survey data, and allowing for both
individual and contextual risk factors.

Social capital and other major risk factors for suicide, namely socioeconomic status and social isolation, are modelled as
latent variables that are proxied (or measured) by observed indicators or question responses for survey subjects. These latent
scales predict suicide risk in the structural component of the model. Also relevant to explaining suicide risk are contextual
variables, such as area deprivation and region of residence, as well as the subject’s demographic status. The analysis is
based on the 2007 Adult Psychiatric Morbidity Survey and includes 7,403 English subjects. A Bayesian modelling strategy is
used.

Models with and without social capital as a predictor of suicide risk are applied. A benefit to statistical fit is demonstrated
when social capital is added as a predictor. Social capital varies significantly by geographic context variables (neighbourhood
deprivation, region), and this impacts on the direct effects of these contextual variables on suicide risk. In particular,
area deprivation is not confirmed as a distinct significant influence. The model develops a suicidality risk score incorporating
social capital, and the success of this risk score in predicting actual suicide events is demonstrated.

Social capital as reflected in neighbourhood perceptions is a significant factor affecting risks of different types of self-harm
and may mediate the effects of other contextual variables such as area deprivation.