Predictor variables for the Dementia Population Risk Tool (DemPoRT) models
| Variable | Scale | Initial variable specification | Full model | Reduced model |
| df | ||||
| Male model | – | 88 (65 main, 23 interaction) | 90 (65 main, 25 interaction) | 74 (51 main, 23 interaction) |
| Female model | – | 88 (65 main, 23 interaction) | 90 (65 main, 25 interaction) | 74 (50 main, 24 interaction) |
| Socio-demographic factors | ||||
| Age* | Continuous | Five knot spline: Valid range: 55–102 (male), 55–101 (female) | Unchanged | Unchanged |
| Sex | Categorical | Stratified: Male; female | Unchanged | Unchanged |
| Ethnicity | Categorical | Seven categories: White; Black; Chinese; Aboriginal; Japanese/Korean/South East Asian/Filipino; other/multiple origin/unknown/Latin American; South Asian/Arab/West Asian | Four categories: White; South Asian/Arab/West Asian; South East Asian/Chinese/Japanese/ Korean/Filipino; other/multiple origin/unknown | Excluded (female) |
| Immigrant | Dichotomous | Yes; no | Unchanged | Excluded |
| Education | Categorical | Four categories: Less than secondary school; secondary school graduation; some post-secondary; post-secondary graduation | Unchanged | Excluded (male) |
| Marital status | Categorical | Four categories: Now married/common-law; separated/divorced; widowed; single | Unchanged | Excluded (male) |
| Neighbourhood deprivation | Ordinal | Three categories: Low (1st or 2nd quintile); high (4th or 5th quintile); moderate (3rd quintile) | Unchanged | Excluded |
| Multilingualism | Dichotomous | – | Multilingual; not multilingual | Excluded (female) |
| General health | ||||
| Sense of belonging | Ordinal | Four categories: Very strong; somewhat strong; somewhat weak; very weak | Unchanged | Excluded |
| Stress | Ordinal | Five categories: Not at all stressful; not very stressful; a bit stressful; quite a bit stressful; extremely stressful | Unchanged | Unchanged |
| Self-rated health | Ordinal | Five categories: Poor; fair; good; very good; excellent | Unchanged | Excluded (female) |
| Health behaviours | ||||
| Smoking status | Categorical | Four categories: Non-smoker; current smoker; former smoker quit <5 years ago; former smoker quit ≥5 years ago | Unchanged | Unchanged |
| Pack years of smoking | Continuous | Three knot spline: Valid range: 0–112 (male), 0–78 (female) | Unchanged | Unchanged |
| Number of drinks last week | Continuous | Three knot spline: Valid range: 0–50 (male), 0–24 (female) | Unchanged | Unchanged |
| Former drinker | Dichotomous | Yes; no | Unchanged | Unchanged |
| Fruit and vegetable consumption | Continuous | Three knot spline: Valid range: 0–48 (male), 0–31 (female) | Unchanged | Unchanged |
| Potato consumption | Continuous | Three knot spline: Valid range: 0–2 | Unchanged | Unchanged |
| Juice consumption | Continuous | Three knot spline: Valid range: 0–6 (male), 0–5 (female) | Unchanged | Unchanged |
| Leisure physical activity (METs) | Continuous | Three knot spline: Valid range: 0–16 (male), 0–12 (female) | Unchanged | Unchanged |
| Functional measures | ||||
| Personal hygiene and care | Dichotomous | Does not need help; needs help | Excluded | – |
| Locomotion in the home | Dichotomous | Does not need help; needs help | Excluded | – |
| Meal preparation | Dichotomous | Does not need help; needs help | Excluded | – |
| Running errands | Dichotomous | Does not need help; needs help | Excluded | – |
| Ordinary housework | Dichotomous | Does not need help; needs help | Excluded | – |
| Heavy housework | Dichotomous | Does not need help; needs help | Excluded | – |
| Finances | Dichotomous | Does not need help; needs help | Excluded | – |
| Number of activities needing help | Categorical | – | Seven categories: None; 1; 2; 3; 4; 5; 6 (sum of above measures, except heavy housework) | Unchanged |
| Health conditions | ||||
| Heart disease | Dichotomous | Yes; no | Unchanged | Unchanged |
| Stroke | Dichotomous | Yes; no | Unchanged | Unchanged |
| Diabetes | Dichotomous | Yes; no | Unchanged | Unchanged |
| Mood disorder | Dichotomous | Yes; no | Unchanged | Unchanged |
| High blood pressure | Dichotomous | Yes; no | Unchanged | Unchanged |
| COPD | Dichotomous | – | Yes; no | Unchanged |
| Epilepsy | Dichotomous | – | Yes; no | Excluded (male) |
| Body mass index | Continuous | Three knot spline: Valid range: 10–44 (male), 10–47 (female) | Unchanged | Unchanged |
| Design | ||||
| Survey year | Ordinal | Six categories: 2001, 2003, 2005, 2007/2008, 2009/2010, 2011/2012 | Unchanged | Unchanged |
*Age interaction included for all variables except socio-demographic, general health and survey-year variables.
COPD, chronic obstructive pulmonary disease; df, degrees of freedom; MET, metabolic equivalent of task.