Table 4 Strength of association of demographic factors with AR manifestation

 Alsowaidiet al., 2010 [3]

7550

OR

0.66 (0.54 - 0.81)

< 0.0005

> 19 years in ref. to 13-19 years: OR adjusted for nationality, gender, family history of AR, and education

 Li et al., 2015 [22]

20,803

OR

1.05 (1.02-1.07)

< 0.05

Continuous variable, 1 year increase (elementary school student)

 Lim et al., 2015 [11]

695

OR

0.72 (0.58 - 0.88)

< 0.01

Continuous variable, 10 year increase (18 - 60 years): OR adjusted for gender, smoking, house dust mite allergy, cat allergy, home dampness, and home renovation

 Ng & Tan, 1994 [36]

2868

OR

0.19 (0.10 – 0.35)

< 0.0001

60-74 years in ref. to 20-39 years: OR adjusted for race, flat size, housing estate, smoking, insect exposure, occupational exposure, and fume

 Ziyab, 2017 [8]

1154

PR

1.04 (1.01 - 1.07)

< 0.01

Continuous variable (18-26 years): PR adjusted for gender, cat exposure, maternal AR, and paternal AR

 Alsowaidi et al., 2010 [3]

7550

OR

0.75 (0.63 - 0.88)

< 0.005

Male in ref. to female: OR adjusted for nationality, age, family history of AR, and education

 Graif et al., 2004 [38]

10,057

OR

0.85 (0.74 – 0.97)

–

Male in ref. to female: OR adjusted for current asthma, family history of asthma, race, residency, and smoking

 Hsu et al., 2009 [10]

1368

OR

0.58 (0.47 – 0.72)

< 0.001

Male in ref. to female: OR adjusted for birth weight, parity, gestational age, maternal education, gestational complications, smoking, pets, carpets, molds, and air pollutions

 Lee et al., 2017 [42]

1497

OR

1.57

< 0.01

Male in ref. to female

 Lei, Yang & Zhen, 2016 [40]

3327

OR

0.68 (0.46 - 1.00)

< 0.05

Male in ref. to female

 Li et al., 2015 [22]

20,803

OR

1.55 (1.41 - 1.70)

< 0.001

Male in ref. to female

 Graif et al., 2004 [38]

10,057

OR

1.75 (1.45 - 2.13)

–

Jews in ref. to Arabs: OR adjusted for current asthma, family history of asthma, gender, residency, and smoking

 Ng & Tan, 1994 [36]

2, 868

OR

2.02 (1.29 - 3.14)

< 0.005

Indian in ref. to Malay: OR adjusted for age, flat size, housing estate, smoking, insect exposure, occupational exposure, and fume

 Norbäck et al., 2016 (2) [35]

462

OR

0.33 (0.13 - 0.88)

< 0.05

Indian in ref. to Malay: OR adjusted for gender, smoking, atopy, and family history of allergic diseases

 Alsowaidi et al., 2010 [3]

7550

OR

0.48 (0.34 - 0.68)

< 0.005

Others in ref. to Arabs: OR adjusted for age, gender, family history of AR, and education

 Graif et al., 2004 [38]

10,057

OR

0.84 (0.90 - 1.40)

–

Urban in ref. to rural: OR adjusted for current asthma, family history of asthma, gender, gender, and smoking

 Lee et al., 2017 [42]

1497

OR

0.71

< 0.05

Townhouse in ref. to others

 Li et al., 2014 [7]

9899

OR

1.91 (1.37 - 2.68)

< 0.001

Urban in ref. to rural

 Min et al., 1997 [20]

10,054

OR

5.26 (2.27 - 12.50)

< 0.05

Urban in ref. to rural: OR adjusted for age

 Li et al., 2015 [22]

20,803

OR

2.19 (1.97 - 2.43)

< 0.001

Cities SH, GZ, WH, CD in ref. to XA, HA, HO, UR

 Ng & Tan, 1994 [36]

2868

OR

1.92 (1.07 - 3.46)

< 0.05

Toa Payoh in ref. to Yishun

: OR adjusted for age, flat size, race, smoking, insect exposure, occupational exposure, and fume

 Bunnag et al., 2000 [37]

3124

OR

1.97 (1.23 - 3.16)

< 0.05

High income in ref. to medium income: adjusted OR

 Li et al., 2015 [22]

20,803

OR

1.42 (1.21 - 1.68)

< 0.001

800-1500 RMB/month in ref. to 800 RMB/month

1.93 (1.64 - 2.27)

< 0.001

1500-2500 RMB/month in ref. to 800 RMB/month

2.88 (2.47 - 3.37)

< 0.001

> 2500 RMB/month in ref. to 800RMB/month

Phathammavong et al., 2008 [9]

536

OR

2.23 (1.04 - 4.81)

< 0.05

High income in ref. to low income: OR adjusted for gender, age, parity, parents education, pets ownership, sharing bed, air conditioning, measles infection, respiratory infection, time on road, meat, fish, vegetables, cow milk, fast food and eggs consumptions, and intestinal parasitic infestation

 Hsu et al., 2009 [10]

1368

OR

1.42 (1.02 - 1.97)

< 0.025

N = 1 in ref. to N ≥ 3

: OR adjusted for birth weight, gender, gestational age, maternal education, gestational complications, smoking, pets, carpets, molds, and air pollutions

1.43 (1.01 - 2.01)

< 0.025

N = 2 in ref. to N ≥ 3: OR adjusted for birth weight, gender, gestational age, maternal education, gestational complications, smoking, pets, carpets, molds, and air pollutions

 Li et al., 2015 [22]

20,803

OR

1.26 (1.05 - 1.51)

< 0.005

N < 3 in ref. to N ≥ 4

1.18 (1.0 - 1.30)

< 0.005

N = 3 in ref. to N ≥ 4

 An et al., 2015 [2]

31,217

OR

0.85 (0.74 - 0.97)

< 0.05

Married in ref. to unmarried: OR adjusted for age, gender, family size, residency, educational, Household income, and occupation