Table 5.
Ordinal logistic regression for association between socioeconomic status (SES) and headache impact (HIT-6). Addition of interaction “SES * depression” to Model 4
| Model 5 | |||
|---|---|---|---|
| b | SE | 95% CI | |
| SES (ref. = high) | |||
| Low SES | .618* | .254 | 0.12, 1.11 |
| Medium SES | .233 | .195 | -0.15, 0.62 |
| Other Sociodemographic variables | |||
| Sex (ref. = men) | .559*** | .156 | 0.25, 0.87 |
| Age | -.005 | .007 | -0.02, 0.01 |
| Marital status (ref. = married) | |||
| Unmarried | .110 | .259 | -0.40, 0.62 |
| Divorced | -.039 | .279 | -0.59, 0.51 |
| Widowed | -.433 | .365 | -1.15, 0.28 |
| Living without partner (ref. = living with partner) | -.058 | .237 | -0.52, 0.41 |
| Children < 18 years (ref. = no) | .079 | .191 | -0.30, 0.45 |
| Living in a rural area (ref. = living in an urban area) | .135 | .214 | -0.28, 0.55 |
| Headache-related variables | |||
| Analgesic use (days a month) | .086*** | .016 | 0.05, 0.12 |
| Headache duration (in years) | .002 | .007 | -0.01, 0.01 |
| Headache frequency (ref. = less than 4 days a month) | |||
| 4–14 days a month | 1.212*** | .210 | 0.80, 1.62 |
| > 14 days a month | .673 | .448 | -0.21, 1.55 |
| Migraine (ref. = no) | 1.485*** | .182 | 1.13, 1.84 |
| Other health variables | |||
| Physical inactivity (ref. = physical active persons) | .213 | .158 | -0.10, 0.52 |
| Obesity (BMI ≥ 30) (ref. = no obesity) | .203 | .184 | -0.16, 0.56 |
| Depressive symptoms (PHQ) (ref. = no depressive symptoms) | .452 | .752 | -1.02, 1.93 |
| Interaction | |||
| SES * Depressive symptoms (ref. = high SES; no depressive symptoms) | |||
| Low SES: depressive symptoms (ref. = no depressive symptoms) | -.077 | .894 | -1.83, 1.68 |
| Medium SES: depressive symptoms (ref. = no depressive symptoms) | .273 | .793 | -1.28, 1.83 |
| Model fitting: χ2 (df) | 272.77 (20) *** | ||
| Goodness of fit | |||
| (Pearson) χ2 (df) | 2183.62 (2248) | ||
| (Deviance) χ2 (df) | 1652.73 (2248) | ||
| Pseudo-R2 (Nagelkerke`s) | .336 | ||
| Test of proportional odds: χ2 (df) | 58.85 (40)* | ||
b slope estimate, SE standard error, df degree of freedom; * p < .05; ** p < .01; *** p < .001; CI confidence interval, ref. reference, BMI body mass index, PHQ Patient Health Questionnaire, depressive subscale encompasses two items and has sum scores ranging from 0 to 6, scores ≥ 3 indicate depressive symptoms