Table 2.

Variable Assignment Table

Datum	Assignment
Age (years)	60-70 years = 1; 71–80 years =2
Education	Primary school = 1; middle school = 2; college =3
Do you live with your children?	Yes =0, No = 1
Monthly income	Monthly income <2000 yuan = 1, 12,000–5000 yuan = 2,>5000 yuan =3
Course of disease	<12 months = 1, 12–24 months = 2,>24 months =3
Domicile	Downtown = 1; Rural =2
History of chronic diseases	<3 = 1; ≥3 =2
Multiple medications	≤4 types = 0, ≥5 types =1
Education about oral health behaviors	Yes = 0, No=1