Table 5.
Adjusted Poisson regression models for social contact/support and cognitive impairment, including interactions with age or education.
| Respondent age |
Respondent education |
|||||||
|---|---|---|---|---|---|---|---|---|
| Variable | 40–59 | Age ≥60 | None | Any | ||||
| Named contacts (count) | 0.65 | [0.52, 0.79] | 0.79 | [0.72, 0.86] | 0.79 | [0.72, 0.86] | 0.67 | [0.53, 0.83] |
| Communication events per month (SD) | 0.50 | [0.36, 0.68] | 0.79 | [0.67, 0.93] | 0.75 | [0.64, 0.89] | 0.63 | [0.47, 0.85] |
| Contact kinship | ||||||||
| Named kin (count) | 0.79 | [0.63, 0.99] | 0.86 | [0.80, 0.93] | 0.85 | [0.79, 0.92] | 0.83 | [0.66, 1.05] |
| Percent named contacts who are kin (10%age points)† | 0.46 | [0.22, 0.97] | 0.61 | [0.46, 0.81] | 0.65 | [0.49, 0.88] | 0.25 | [0.11, 0.53] |
| Any named non-kin (binary) | 1.05 | [0.94, 1.17] | 1.06 | [1.02, 1.10] | 1.04 | [1.00, 1.08] | 1.20 | [1.06, 1.35] |
| Contact distance‡ | ||||||||
| Same household (count) | 0.90 | [0.60, 1.33] | 0.87 | [0.77, 0.98] | 0.88 | [0.78, 0.98] | 0.88 | [0.63, 1.22] |
| Same village (count) | 0.55 | [0.42, 0.73] | 0.76 | [0.66, 0.87] | 0.75 | [0.66, 0.84] | 0.56 | [0.38, 0.83] |
| Agincourt area (count) | 0.44 | [0.29, 0.66] | 0.83 | [0.70, 0.97] | 0.78 | [0.64, 0.95] | 0.68 | [0.50, 0.92] |
| Elsewhere South Africa (count) | 0.74 | [0.57, 0.95] | 0.76 | [0.65, 0.89] | 0.77 | [0.67, 0.88] | 0.70 | [0.47, 1.05] |
| Egonet effective size | ||||||||
| Effective size (range 1–5.7)† | 0.97 | [0.42, 2.24] | 0.84 | [0.60, 1.18] | 0.84 | [0.49, 1.46] | 0.90 | [0.61, 1.34] |
| Support types | ||||||||
| Information support per month (SD) | 0.61 | [0.36, 1.03] | 0.76 | [0.68, 0.86] | 0.73 | [0.65, 0.82] | 0.75 | [0.56, 1.02] |
| Emotional support per month (SD) | 0.62 | [0.41, 0.96] | 0.75 | [0.66, 0.85] | 0.74 | [0.65, 0.83] | 0.70 | [0.49, 1.00] |
| Financial support per month (SD) | 0.93 | [0.69, 1.27] | 0.86 | [0.78, 0.94] | 0.87 | [0.79, 0.96] | 0.87 | [0.65, 1.15] |
| Physical support per month (SD) | 0.67 | [0.39, 1.16] | 0.79 | [0.70, 0.88] | 0.79 | [0.71, 0.87] | 0.68 | [0.52, 0.90] |
Note. Each pair of regression coefficients (e.g. 40–59/≥60 on one row) represents results from a different model, except ‘contact distance’ models (‡), where all four variables were included in a single regression. All models are hierarchical (individuals nested in interviewers). Poisson regressions with robust error variance and are adjusted for age, gender, employment status, household size, household wealth, educational attainment, literacy, marital status, father's occupation, childhood self-rated health status, and interview month. †Models for kin contact percentage and egonet effective size are also adjusted for the number of contacts named. Values for all models are prevalence rate ratios (and 95% confidence intervals) associated with a one-unit higher value of the variables as shown in the first column. IQR: Interquartile range; SD: Standard deviation.