Estimated effects (coefficients and relative % change) of individual characteristics on average daily steps in subjects at high risk of CVD
| Variables | Model 1† | Model 2‡ | ||
| Coefficient | Relative % Change (95% CI) | Coefficient | Relative % Change (95% CI) | |
| Constant | 8.813 | 8.937 | ||
| Basic confounders | ||||
| Age (impact additional year) | 0.004 | 0.4 (−0.1 to 1.0) | −0.012*** | −1.2 (−1.7 to −0.6) |
| Gender | ||||
| Male | 0 | 0 | 0 | 0 |
| Female | −0.249*** | −22.1 (−26.7 to −17.2) | −0.149*** | −13.8 (−18.9 to −8.5) |
| Day | ||||
| Weekday | 0 | 0 | 0 | 0 |
| Weekend | −0.161*** | −14.9 (−16.6 to −13.2) | −0.161*** | −14.9 (−16.6 to −13.1) |
| Season | ||||
| Spring | 0 | 0 | 0 | 0 |
| Summer | −0.007 | −0.7 (−6.7 to 5.7) | 0.004 | 0.4 (−5.4 to 6.7) |
| Autumn | −0.013 | −1.3 (−7.2 to 5.0) | −0.015 | −1.5 (−7.2 to 4.5) |
| Winter | −0.086** | −8.3 (−13.8 to −2.4) | −0.098** | −9.3 (−14.5 to −3.8) |
| Added covariates | ||||
| a) Depressive symptoms constant | 8.84 | |||
| None (PHQ-9: 0–4) | 0 | 0 | 0 | 0 |
| Mild (PHQ-9: 5–9) | −0.177*** | −16.2 (−21.5 to −10.6) | −0.142*** | −13.3 (−18.6 to −7.6) |
| Moderate/Severe (PHQ-9 ≥ 10) | −0.211*** | −19.0 (−27.2 to −10.0) | −0.170** | −15.6 (−23.8 to −6.6) |
| b) Ethnicity constant | 8.845 | |||
| White | 0 | 0 | 0 | 0 |
| Black/Asian/other | −0.145*** | −13.5 (−19.2 to −7.4) | −0.196*** | −17.8 (−23.3 to −12.0) |
| c) Education level constant | 8.845 | |||
| Level 3: A Level or higher | 0 | 0 | 0 | 0 |
| Level 2: O Level/GCSE/NVQ | −0.063* | −6.1 (−10.7 to −1.2) | −0.054* | −5.3 (−9.7 to −0.6) |
| Level 1: no formal qualification | −0.072** | −7.0 (−11.7 to −2.0) | −0.196* | −5.7 (−10.4 to −0.9) |
| d) BMI constant | 8.811 | |||
| Impact of one unit BMI increase | −0.025*** | −2.4 (−2.9 to −1.9) | −0.027*** | −2.7 (−3.2 to −2.2) |
| e) Smoking status constant | 8.849 | |||
| Never smoked | 0 | 0 | 0 | 0 |
| Ex-smoker | −0.023 | −2.3 (−6.9 to −2.5) | −0.038 | −3.7 (−8.2 to 0.9) |
| Current smoker | −0.141*** | −13.2 (−18.9 to −7.0) | −0.212*** | −19.1 (−24.4 to −13.4) |
| f) AUDIT score constant | 8.824 | |||
| Low risk (score 1 – 7) | 0 | 0 | 0 | 0 |
| Possibly harmful (score ≥ 8) | −0.001 | −0.1 (−5.8 to 6.0) | 0.032 | 3.3 (−2.4 to 9.3) |
| Abstainer (score 0) | −0.124** | −11.7 (−17.6 to −5.2) | −0.092* | −8.8 (−14.9 to −2.2) |
Significance levels: *P<0.05, **P<0.01 and ***P<0.001.
†Model 1: all variables (a-f) adjusted for basic confounders (age, gender, day and season) only. Note: there is a constant for the basic confounders only model and separate constants for this model adjusted for each added covariate (a–f).
‡Model 2: all variables are mutually adjusted; thus, there is only one constant for the whole model.
The reference group within each category is set to 0.
AUDIT, Alcohol Use Disorders Identification Test; BMI, body mass index; CVD, cardiovascular disease; GCSE, General Certificate of Secondary Education; NVQ, National Vocational Qualification; PHQ-9, Patient Health Questionnaire-9.