Table 1.

Operationalization of the study variables and their categorization for analyses

Variables	O Original measurement ( (codes)	Bivariate analyses (codes)	Multivariate analyses (codes)
Study Outcomes: Xerostomia	Self-reported mouth dryness: '1' never, '2' sometimes, '3' often, '4' always	'1' never/sometimes, '2' often/always	'1' control group, '2' xerostomia group
Sicca syndrome	'1' Sicca syndrome '2' Non-Sicca syndrome	'1' Objective symptoms of Sicca syndrome '2' No objective symptoms of Sicca syndrome
Indicators:
Gender	1) males, 2) females	'1' males, '2' females	'1' males, '2' females
Age	In full years	'1′ 35–46 years, '2′ 47–60 yrs.; '3′ 61–74 yrs	'1′ 35–60 yrs.; '2′ 61–74 yrs
Residence	Location of residence: '1' urban; '2' peri-urban; '3' rural	‘1’ urban; ‘2’ peri-urban; ‘3’ rural	'1' urban; '2' peri-urban/rural
Education	In full years	'1' ≤ secondary; '2' college; '3' university +	'1' secondary or less; '2' college/university or more
Systemic diseases (Total number)	Any systemic condition	'1' none; '2' one, '3' two or more conditions	'1' none; '2' one or more
Medications (Total number)	Any medication	'1' none; '2' one, '3' two or more	'1' none; '2' one or more
Perceived stress Total stress score (%)	10 questions (responses: '0' never; '1' rarely; '2' sometimes; '3' often; '4' very often. calculated from responses 3 and 4 and adjusted for the number of answers	'1' low; '2' medium, '3' high/very high	'1' low; '2' medium/high/very high
Body Mass Index (BMI)	Based on weight & height (BMI = kg/m2)	'1' BMI ≤ 25.0; '2' BMI 25.1–29.9; '3' BMI ≥ 30	'1' underweight/normal; '2' overweight/obese
Smoking	'1' no; '2' yes	'1' no; '2' yes	'1' no '2' yes;
Daily alcohol use in units1	Alcohol consumed in the past month: '0' none; '1' one unit; '2' two units, '3' units; '4' units; '5' five or more	'1' no; '2' yes	'1' no; '2' yes

¹One unit of alcohol: one beer or glass of wine or a small goblet of heavy liquor