Skip to main content

Table 2 List of confounders and covariates used in propensity score processing

From: The impact of racism on the future health of adults: protocol for a prospective cohort study

Variable Groups/levels Comments
VARIABLES INCLUDED IN FINAL PROPENSITY SCORE MODEL
Prioritised ethnicity Māori
Pacific
Asian
Other (Middle Eastern, Latin American, African, and Other)
European/NZ European
Variable used to stratify groups prior to calculation of propensity scores
Nativity Born in New Zealand
Born outside New Zealand
 
Age group Ten-year age bands (15–24, 25–34, 35–44, 45–54, 55–64, 65–74, 75+) Treated as categorical variable
Gender Female
Male
 
NZDep2013 Quintile [54] Quintiles 1–5 Treated as categorical variable
Highest educational qualification Less than upper secondary
Upper secondary
Tertiary
Other
“Other” category included qualification responses that could not be coded to an existing response category.
Employment status Currently working
Looking for work
Not in labour force
Not in labour force (aged 65+)
Other
“Not in labour force” group split into those below and above retirement age (65+).
“Other” category included responses that could not be coded to an existing response category.
VARIABLES CONSIDERED BUT NOT INCLUDED IN FINAL PROPENSITY SCORE MODEL
Baseline self-rated health Excellent/Very good/Good
Fair/Poor
Health measure: not included as analysis adjusts for baseline
Baseline mental distress (K10 scale) Continuous variable (score 0–40) Health measure: not included as analysis adjusts for baseline
Smoking status Current smoker (at least monthly)
Not current smoker
Health measure: not included (also substantial missing data)
Index of Multiple Deprivation [55] (IMD) Decile for total IMD score Overlap with NZDep quintile; did not improve balance
IMD [55] Employment Subscale Decile for employment measures in local area Overlap with NZDep quintile (individual level employment also already included)