Table 4.
Associations of Tumor Stage, Age, Socioeconomic Position, and Residential Distance From a Hospital With Being Lost to Follow-upa, African Breast Cancer—Disparities in Outcomes Study, 2014–2018
| Uganda and Namibia | Zambia | |||||||
|---|---|---|---|---|---|---|---|---|
| Variable | No. | % | SHR b | 95% CI | No. | % | SHR b | 95% CI |
| Tumor stage | ||||||||
| I or II | 13 | 4 | 1.00 | Referent | 10 | 14 | 1.00 | Referent |
| III | 13 | 3 | 0.85 | 0.39, 1.84 | 16 | 19 | 1.12 | 0.51, 2.47 |
| IV | 2 | 2 | 0.35 | 0.78, 1.58 | 0 | 0 | ||
| Missing data | 3 | 9 | 1.86 | 0.51, 6.76 | 11 | 30 | 1.72 | 0.74, 4.01 |
| Age group at diagnosis, years | ||||||||
| <35.0 | 8 | 8 | 2.57 | 0.97, 6.84 | 9 | 30 | 1.06 | 0.45, 2.46 |
| 35.0–44.9 | 7 | 3 | 1.02 | 0.37, 2.84 | 10 | 20 | 0.83 | 0.36, 1.91 |
| 45.0–54.9 | 8 | 3 | 1.00 | Referent | 15 | 27 | 1.00 | Referent |
| 55.0–64.9 | 7 | 4 | 1.50 | 0.56, 4.07 | 1 | 3 | 0.13 | 0.02, 0.99 |
| ≥65.0 | 1 | 1 | 0.24 | 0.03, 2.00 | 2 | 6 | 0.15 | 0.03, 0.68 |
| Age, per 10-year increment | 0.76 | 0.57, 1.01 | 0.74 | 0.59, 0.92 | ||||
| Distance to hospital, per 100-km increment | 1.15 | 1.03, 1.28 | 0.92 | 0.76, 1.11 | ||||
| Socioeconomic positionc | ||||||||
| Low | 13 | 3 | 1.00 | Referent | 14 | 20 | 1.00 | Referent |
| Middle | 10 | 4 | 1.50 | 0.69, 3.28 | 16 | 22 | 0.84 | 0.39, 1.84 |
| High | 8 | 4 | 1.23 | 0.50, 3.00 | 7 | 12 | 0.38 | 0.15, 0.97 |
| Socioeconomic position, per tertile increment | 1.13 | 0.75, 1.69 | 0.64 | 0.42, 0.98 | ||||
Abbreviations: CI, confidence interval; SHR, subhazard ratio.
a Assessed using SHRs in a competing-risks survival model. Because of the small numbers of women lost to follow-up in Nigeria (n = 3 at 3 years), Nigeria was not included in this analysis.
b SHR estimated from a competing-risk regression model with death as a competing event, adjusted for population group (Uganda and Namibia), tumor stage at diagnosis, socioeconomic position, and age (linear increase per year).
c Low, medium, and high socioeconomic position were calculated, by country, as tertiles of a socioeconomic position score (range, 1–10) based on the following self-reported possessions and facilities: home ownership; indoor water; flush toilet; electricity; vehicle; refrigerator; landline telephone; gas or electric stove; and bed.