Table 2 Distribution of age at onset of smoking and incidence rate of smoking among ever-smokers
Characteristics | n | Age at Onset of Tobacco Smoking(n = 3360) | |||||
|---|---|---|---|---|---|---|---|
< 10 year | 10–19 year | 20–29 year | After 30 year | Median | IQR | ||
Age in years | |||||||
< 20 | 450 | 2 [0.9–4.6] | 92.1 [87.4–95.1] | 5.9 [3.3–10.4] | 0.0 [0.0–0.0] | 16 | 3 |
20–29 | 743 | 2.1 [1.1–4.0] | 66.4 [61.7–70.8] | 31.0 [26.8–35.7] | 0.5 [0.1–1.7] | 18 | 4 |
30–39 | 595 | 1.7 [0.8–3.9] | 56.7 [50.3–63.0] | 35.3 [29.5–41.6] | 6.2 [4.0–9.4] | 18 | 5 |
40–49 | 670 | 0.5 [0.2–1.3] | 47.5 [42.2–52.9] | 38.4 [33.4–43.6] | 13.7 [9.4–19.4] | 20 | 8 |
50–59 | 557 | 1 [0.4–2.3] | 48.3 [40.7–55.9] | 33.5 [27.6–39.9] | 17.3 [13.4–22.0] | 20 | 8 |
> =60 | 331 | 1.5 [0.5–4.6] | 39.4 [29.5–50.2] | 31.9 [23.8–41.4] | 27.2 [16.9–40.7] | 20 | 13 |
Sex | |||||||
Males | 2218 | 1.7 [1.0–2.7] | 59.1 [56.1–62.1] | 33.0 [30.2–35.8] | 6.2 [5.1–7.6] | 18 | 5 |
Females | 1113 | 1.1 [0.6–2.0] | 59.0 [53.2–64.6] | 24.6 [20.6–29.1] | 15.4 [10.8–21.4] | 18 | 6 |
Location | |||||||
Rural | 895 | 1.9 [1.1–3.5] | 54.7 [50.0–59.3] | 34.2 [30.1–38.6] | 9.2 [7.2–11.6] | 18 | 6 |
Urban | 2451 | 1.3 [0.8–2.2] | 60.9 [57.5–64.2] | 29.4 [26.5–32.5] | 8.4 [6.4–11.0] | 18 | 5 |
Geographic Location | |||||||
Urban Formal | 2084 | 1.3 [0.7–2.3] | 60.9 [57.0–64.6] | 29.5 [26.2–32.9] | 8.4 [6.1–11.3] | 18 | 5 |
Urban Informal | 367 | 1.5 [0.6–3.5] | 60.9 [55.2–66.3] | 29.1 [23.7–35.1] | 8.6 [5.8–12.4] | 18 | 5 |
Rural Informal (Tribal) | 418 | 2.2 [1.0–4.6] | 52.1 [46.7–57.5] | 35.8 [30.7–41.4] | 9.9 [7.4–13.0] | 18 | 7 |
Rural Formal (Farms) | 477 | 1.5 [0.7–3.6] | 59.4 [50.7–67.6] | 31.2 [24.7–38.6] | 7.8 [5.0–11.9] | 18 | 5 |
Province | |||||||
Western Cape | 897 | 2.1 [1.3–3.5] | 74.9 [69.3–79.8] | 19 [15.6–23.0] | 3.9 [2.2–6.7] | 17 | 4 |
Eastern Cape | 400 | 1.2 [0.3–4.0] | 49.7 [43.7–55.7] | 36.9 [31.6–42.5] | 12.3 [9.0–16.5] | 19 | 7 |
Northern Cape | 356 | 1.6 [0.3–7.9] | 64.1 [55.3–72.1] | 27.7 [20.2–36.7] | 6.6 [3.7–11.5] | 18 | 4 |
Free State | 249 | 0.9 [0.2–3.9] | 47.8 [41.0–54.7] | 42.8 [35.1–50.8] | 8.5 [5.5–13.0] | 20 | 6 |
Kwazulu Natal | 472 | 2.4 [0.9–6.2] | 59.3 [51.5–66.6] | 27.7 [21.9–34.3] | 10.6 [5.6–19.4] | 18 | 5 |
North West | 238 | 0.2 [0.0–1.7] | 51.8 [44.6–58.9] | 35.7 [29.5–42.4] | 12.3 [8.5–17.6] | 19 | 5 |
Gauteng | 380 | 0.1 [0.0–0.8] | 55.3 [48.4–62.0] | 35 [27.8–42.9] | 9.6 [5.7–15.7] | 19 | 6 |
Mpumalanga | 188 | 0.4 [0.1–2.5] | 51.3 [43.3–59.3] | 38.9 [31.8–46.5] | 9.4 [6.6–13.2] | 19 | 7 |
Limpopo | 166 | 3.8 [1.6–8.5] | 54.9 [43.0–66.3] | 33.7 [24.5–44.3] | 7.6 [4.3–13.3] | 18 | 7 |
Race | |||||||
African | 1591 | 1.8 [1.1–2.9] | 52.0 [48.8–55.2] | 36.1 [33.2–39.1] | 10.1 [8.6–11.8] | 19 | 6 |
White | 177 | 0.8 [0.3–2.7] | 65.7 [53.1–76.4] | 21.2 [13.1–32.5] | 12.3 [4.9–27.5] | 18 | 4 |
Coloured | 1285 | 1.3 [0.6–2.5] | 76.4 [72.8–79.6] | 19.8 [16.9–23.2] | 2.5 [1.7–3.8] | 17 | 4 |
Indian | 270 | 0.3 [0.1–1.4] | 61.1 [54.0–67.8] | 31.9 [23.9–41.1] | 6.6 [3.7–11.6] | 18 | 4 |
Other | 1 | ISS | ISS | ISS | ISS | ISS | ISS |
Nationality | |||||||
South African Citizen | 3266 | 1.5 [1.0–2.3] | 59 [56.3–61.7] | 30.8 [28.4–33.2] | 8.7 [7.1–10.6] | 18 | 5 |
Non - Citizen (PR) | 24 | ISS | ISS | ISS | ISS | ISS | ISS |
Non-Citizen (Refugee) | 10 | ISS | ISS | ISS | ISS | ISS | ISS |
Other (Specify) | 1 | ISS | ISS | ISS | ISS | ISS | ISS |
Marital Status | |||||||
Never Married | 1183 | 2.0 [1.1–3.8] | 64.5 [60.3–68.5] | 27.7 [24.2–31.4] | 5.8 [4.3–7.8] | 18 | 5 |
Currently Married | 1430 | 1.1 [0.6–1.8] | 55.7 [51.3–59.9] | 32.9 [29.1–36.9] | 10.4 [8.0–13.4] | 18 | 4 |
Formerly Married | 281 | 0.3 [0.1–1.4] | 41.3 [31.4–52.0] | 36.5 [27.3–46.8] | 21.9 [10.8–39.2] | 20 | 4 |
Employment Status | |||||||
Unemployed | 1663 | 1.6 [1.0–2.8] | 60.2 [56.6–63.7] | 29.6 [26.4–32.9] | 8.6 [7.1–10.4] | 18 | 5 |
Employed | 1214 | 1.3 [0.7–2.4] | 57.6 [53.3–61.8] | 33.6 [29.8–37.6] | 7.5 [5.3–10.7] | 18 | 6 |
Educational Attainment | |||||||
No formal education | 896 | 1.6 [0.8–3.5] | 49.0 [44.0–54.0] | 33.9 [29.5–38.5] | 15.5 [12.6–18.9] | 19 | 8 |
Grade 8–12 | 1758 | 1.5 [0.9–2.5] | 62.0 [58.2–65.6] | 29.8 [26.6–33.1] | 6.8 [4.6–9.8] | 18 | 4 |
Higher education | 219 | 0.5 [0.1–2.9] | 62.7 [51.5–72.7] | 30.0 [21.5–40.1] | 6.8 [2.2–19.1] | 18 | 4 |
Wealth Quintile | |||||||
Lowest | 558 | 1.3 [0.6–2.8] | 50.8 [45.4–56.2] | 37 [31.9–42.3] | 10.9 [8.1–14.6] | 19 | 7 |
Lower | 462 | 5.1 [2.5–10.1] | 52.8 [46.7–58.9] | 30.9 [25.5–36.9] | 11.2 [7.7–15.9] | 18 | 7 |
Middle | 506 | 1.6 [0.7–3.9] | 60.9 [54.1–67.4] | 30.2 [24.1–37.2] | 7.2 [4.7–10.8] | 18 | 5 |
Higher | 716 | 1 [0.4–2.4] | 61.6 [55.4–67.5] | 31 [25.9–36.7] | 6.4 [4.7–8.7] | 18 | 4 |
Highest | 560 | 0.6 [0.3–1.6] | 64.8 [57.0–71.9] | 26.9 [20.6–34.3] | 7.7 [3.2–17.3] | 18 | 4 |
Total | 3360 | 1.5 [1.0–2.2] | 59.1 [56.4–61.7] | 30.8 [28.4–33.3] | 8.6 [7.0–10.5] | 18 | 5 |