Table 3.
Demographic characteristics of participants
| Characteristic | Study population (n = 278) | Target populationc | Fisher’s exact P value | |||
| na | % | 95% CIb | ||||
| Age group (years) | ||||||
| 16–17 | 38 | 14% | 9.60–17.7 | 19.8% | ||
| 18–21 | 115 | 41.4% | 35.5–47.2 | 40.1% | ||
| 22–25 | 125 | 44.9% | 39.1–50.8 | 40.1% | .02 | |
| Geographic region | ||||||
| Major city | 211 | 76.5% | 71.4–81.5 | 78.7% | ||
| Inner regional | 49 | 18% | 13.2–22.3 | 17.7% | ||
| Outer regional/remote | 16 | 6% | 3.0–8.6 | 3.6% | .15 | |
| Country of birth | ||||||
| Australia | 230 | 83.3% | 78.9–87.8 | 80.2% | ||
| Other | 46 | 17% | 12.2–21.1 | 19.8% | .23 | |
| Indigenous status | ||||||
| Aboriginal or Torres Strait Islander | 3 | 1% | 0.06–2.10 | 0.85% | ||
| Other | 275 | 98.9% | 97.9–99.9 | 99.15% | .51 | |
| Socioeconomic level (SEIFA percentile)d | ||||||
| <55 | 83 | 30% | 24.6–35.5 | 33.9% | ||
| 55–80 | 87 | 32% | 26.0–37.0 | 32.7% | ||
| >80 | 106 | 38.4% | 32.6–44.2 | 33.4% | .19 | |
| Education level | ||||||
| < Year 12e | 54 | 19% | 15.5–23.3 | 28.4% | ||
| Year 12 | 104 | 37.4% | 32.6–42.2 | 38.1% | ||
| > Year 12 | 120 | 43.2% | 37.3–49.0 | 33.5% | <.001 | |
| Body mass index (kg/m2), 18- to 24-year-oldsf | ||||||
| <18.5 (underweight) | 13 | 6% | 3.6–8.4 | 9.6% | ||
| 18.5–25 (normal) | 128 | 61.0% | 55.6–65.5 | 68.0% | ||
| 25–30 (overweight) | 44 | 21% | 16.6–24.8 | 15.8% | ||
| >30 (obese) | 25 | 12% | 9.4–16.2 | 6.6% | .002 | |
a Numbers may not add up to 278 due to missing data.
b Confidence interval.
c Population data from Australian Bureau of Statistics census 2006, except for body mass index data from the Victorian Population Health Survey 2008, with figures corrected for nonresponses to add up to 100%.
d Based on postal/zip code. Percentiles are the rankings within Victoria. Note that the percentiles are based on the postal codes and are not weighted by the population within each postal code. Major city postal codes have, on average, higher Socio-Economic Indexes for Areas (SEIFA) level and larger population than regional postal codes. Consequently, the population-weighted median SEIFA percentile is about 70%, not 50%.
e Year 12 is the final year of high school in the Australian education system.
f Age range chosen to match that from Victorian Population Health Survey 2008. Consistent with the Survey, we used the World Health Organization classifications of adult body weight status based on body mass index.