Table 1

Prespecification of predictor variables for DemPoRT with initial degrees of freedom (df) allocation

VariableScaleInitial variable specificationdf
Sociodemographic factors
  AgeContinuous5 knot spline: valid range: 55–102 (male), 55–101 (female)4
  SexCategoricalStratified: Male; femaleNA
  EthnicityCategoricalSeven categories: Caucasian; African-American; Chinese; Aboriginal; Japanese/Korean/South East Asian/Filipino; other/multiple origin/unknown/Latin American; South Asian/Arab/West Asian6
  ImmigrantDichotomousYes; no1
  EducationCategoricalFour categories: less than secondary school; secondary school graduation; some postsecondary; postsecondary graduation3
  Marital statusCategoricalFour categories: now married/common law; separated/divorced; widowed; single3
Neighbourhood social and material Deprivation41 OrdinalThree categories: low (1st or 2nd quintile); high 4th or 5th quintile; moderate (3rd quintile)2
General health
  Sense of belonging to local communityOrdinalFour categories: very strong; somewhat strong; somewhat weak; very weak3
  Self-perceived stressOrdinalFive categories: not at all stressful; not very stressful; a bit stressful; quite a bit stressful; extremely stressful4
  Self-rated healthOrdinalFive categories: poor; fair; good; very good; excellent4
Health behaviours
  Pack years of smokingContinuous3 knot spline: valid range: 0–112 (male), 0–78 (female)2
  Smoking statusCategoricalFour categories: non-smoker; current smoker; former smoker quit <5 years ago; former smoker quit >5 years ago3
  Alcohol consumption (number of drinks last week)Continuous3 knot spline: valid range: 0–50 (male), 0–24 (female)2
  Former drinkerDichotomousYes; no1
  Consumption of fruit, salad, carrot and other vegetables (average daily frequency)Continuous3 knot spline: valid range: 0–48 (male), 0–31 (female)2
  Potato consumption (average daily frequency)Continuous3 knot spline: valid range: 0–22
  Juice consumption (average daily consumptionContinuous3 knot spline: valid range: 0–6 (male), 0–5 (female)2
  Leisure physical activity (average daily METs (kcal/kg/day))Continuous3 knot spline: valid range: 0–16 (male), 0–12 (female)2
Functional measures
  Personal hygiene and careDichotomousDoes not need help; needs help1
  Locomotion in the homeDichotomousDoes not need help; needs help1
  Meal preparationDichotomousDoes not need help; needs help1
  Running errandsDichotomousDoes not need help; needs help1
  Ordinary houseworkDichotomousDoes not need help; needs help1
  Heavy houseworkDichotomousDoes not need help; needs help1
  FinancesDichotomousDoes not need help; needs help1
Health conditions
  Heart diseaseDichotomousYes; no1
  StrokeDichotomousYes; no1
  DiabetesDichotomousYes; no1
  Mood disorderDichotomousYes; no1
  High blood pressureDichotomousYes; no1
  Body mass indexContinuous3 knot spline: valid range: 10–44 (male), 10–47 (female)2
  Survey yearOrdinalFour categories: 2000/2001, 2002/2003, 2004/2005, 2006/20073
  • DemPoRT, Dementia Population Risk Tool; METs, metabolic equivalent tasks.