Table 2 Ordinal logistic regression for the association between socioeconomic status (SES) and headache impact (HIT-6). Weighted random sample

SES (ref. = high)

 Low SES

1.028***

.214

0.61, 1.45

.866***

.225

0.43, 1.31

.648*

.239

0.18, 1.12

.602*

.245

0.12, 1.08

 Medium SES

.467**

.171

0.13, 0.80

.397*

.175

0.05, 0.74

.312

.183

-0.05, 0.67

.256

.189

-0.11, 0.63

Other Sociodemographic variables

 Sex (ref. = men)

.844***

.145

0.56, 1.13

.572***

.153

0.27, 0.87

.563***

.156

0.26, 0.87

 Age

.002

.006

-0.01, 0.01

-.003

.006

-0.02, 0.01

-.005

.006

-0.02, 0.01

 Marital status (ref. = married)

  Unmarried

.240

.236

-0.22, 0.70

.231

.252

-0.26, 0.72

.106

.258

-0.40, 0.61

  Divorced

.100

.262

-0.41, 0.61

-.014

.275

-0.55, 0.53

-.049

.279

-0.60, 0.50

  Widowed

-.093

.321

-0.72, 0.53

-.413

.358

-1.11, 0.29

-.448

.364

-1.16, 0.27

 Living without partner (ref. = living with partner)

-.140

.216

-0.56, 0.28

-.150

.232

-0.60, 0.30

-.063

.237

-0.53, 0.40

 Children < 18 years (ref. = no)

-.032

.175

-0.37, 0.31

.039

.186

-0.33, 0.40

.093

.191

-0.28, 0.47

 Living in a rural area (ref. = living in an urban area)

.327

.196

-0.06, 0.71

.134

.212

-0.28, 0.55

.140

.214

-0.28, 0.56

Headache-related variables

 Analgesic use (days a month)

.096***

.015

0.07, 0.13

.086***

.016

0.06, 0.12

 Headache duration (in years)

.003

.006

-0.01, 0.12

.002

.007

-0.01, 0.01

 Headache frequency (ref. = less than 4 days a month)

  4–14 days a month

1.238***

.202

0.84, 1.63

1.215***

.210

0.80, 1.63

  > 14 days a month

.706

.437

-0.15, 1.56

.650

.444

-0.22, 1.52

 Migraine (ref. = no)

1.436***

.179

1.09, 1.79

1.495***

.178

1.15, 1.84

Other health variables

 Physical inactivity (ref. = no)

.212

.158

-0.10, 0.52

 Obesity (BMI ≥ 30) (ref. = no obesity)

.200

.184

-0.16, 0.56

 Depressive symptoms (PHQ) (ref. = no depressive symptoms)

.630**

.233

0.17, 1.09

 Model fitting: χ² (df)

22.70 (2) ***

58.67 (10) ***

259.58 (15) ***

272.34 (18) ***

 Goodness of fit

  (Pearson) χ² (df)

3.85 (4)

1706.33 (1769)

2261.13 (2298)

2185.33 (2250)

  (Deviance) χ² (df)

3.89 (4)

1551.05 (1769)

1710.96 (2298)

1653.16 (2250)

 Pseudo-R² (Nagelkerke`s)

.031

.079

.316

.336

 Test of proportional odds: χ² (df)

3.89 (4)

21.57 (20)

40.00 (30)

45.27 (36)