Supplementary Material for Manuscript the Interactive Role of Income (Material Position)

Supplementary Material for Manuscript the Interactive Role of Income (Material Position)

Supplementary material for manuscript “The Interactive Role of Income (material position) and Income Rank (psychosocial position) in Psychological Distress: A 9-year Longitudinal Study of 30,000 UK Parents”. Social Psychiatry and Psychiatric Epidemiology. Elisabeth A. Garratt[1], Tarani Chandola, Kingsley Purdam, Alex M. Wood.

Online Resource 1

This supplementary material replicates all analyses included in the manuscript, defining income rank and distance from the mean using comparison groups defined by (a) countries (England, Scotland, Wales, Northern Ireland); and (b) the UK. This was only possible for parents living in England because Wales, Scotland, Northern Ireland are defined as regions and not subdivided any further, so their comparison groups are the same for region, country, and the UK.


Table 1 Linear fixed-effects panel regression analyses of parents’ log-transformed Kessler scores predicted by exponentiated coefficients of absolute income, income rank, non-linear income terms and income interactions, adjusted for covariates, using country comparison groups, England only (n=47,731)

Model 1Model 2Model 3Model 4Model 5Model 6
Fixed effects (exponentiated coefficients, se)
Absolute
income
0.653***
(0.026)
1.102
(0.186)
0.357***
(0.027)
0.355***
(0.027)
Country income rank 0.905**
(0.022)
0.969
(0.072)
1.550***
(0.069)
1.938***
(0.118)
Non-linear terms (exponentiated coefficients, se)
Absolute income squared 0.654***
(0.084)
Country income rank squared 0.942
(0.060)
Interaction effects (exponentiated coefficients, se)
Absolute income X Country middle rank 0.900***
(0.027)
Absolute income X Country high rank 0.822***
(0.033)
Goodness-of-fit
AIC56,43256,61756,43356,63956,27756,231

Table 2 Linear fixed-effects panel regression analyses of parents’ log-transformed Kessler scores predicted by exponentiated coefficients of absolute income, income rank, non-linear income terms and income interactions, adjusted for covariates, using UK comparison groups, England only (n=47,731)

Model 1Model 2Model 3Model 4Model 5Model 6
Fixed effects (exponentiated coefficients, se)
Absolute
income
0.653***
(0.026)
1.102
(0.186)
0.365***
(0.027)
0.364***
(0.027)
Country income rank 0.905**
(0.021)
0.951
(0.070)
1.515***
(0.066)
1.929***
(0.117)
Non-linear terms (exponentiated coefficients, se)
Absolute income squared 0.654***
(0.084)
UK income rank squared 0.959
(0.061)
Interaction effects (exponentiated coefficients, se)
Absolute income X UK middle rank 0.883***
(0.026)
Absolute income X UK high rank 0.806***
(0.032)
Goodness-of-fit
AIC56,43256,61656,43356,63956,28556,233


1


Figure 1 Slope of the marginal effects of interactions between absolute income and income rank defined within comparison groups of (a) UK (b) Country (c) Region on parents’ log-transformed Kessler scores, parents living in England only

1


1


[1] Corresponding author. Nuffield College, New Road, Oxford, England OX1 1NF. Tel +4418 6527 8517. Fax: +44 1865 278621. Email