Figure 2. Sample Distribution.

Populations aged 15 years and younger, as reported in the footnotes, are as estimated on December 31, 2012 (Australian Bureau of Statistics; Australian Demographic Statistics, series 3101). The percentage of the population that was metropolitan, as reported in the footnotes, was calculated on population estimates (aged ≤15 years) from state departments of health. Each square and circular pin identifies a health district that was sampled within the metropolitan and regional strata; pins in the regional strata are approximately at the center of the sampled health district to prevent identification of individual sites. Numbers in squares and circular pinheads are the sum of general practitioners (GPs), pediatricians, and nontertiary hospitals recruited in a health district, except for 8 pediatricians (shown with an asterisk) all recruited from metropolitan South Australia (see Figure 3, footnote g). Triangular pins mark the approximate location of tertiary pediatric hospitals, and the number in the triangles indicate the number of tertiary hospitals in that location.

^aQueensland: population aged ≤15 years, 976 821; percentage of population that was metropolitan, 66%; total recruited: 35 GPs, 4 pediatricians, and 12 hospitals.

^bSouth Australia: population aged ≤15 years, 314 511; percentage of population that was metropolitan, 68%; total recruited: 28 GPs, 8 pediatricians, and 7 hospitals.

^cNew South Wales: population aged ≤15 years, 1 479 680; percentage of population that was metropolitan, 70%; total recruited: 22 GPs, 8 pediatricians, and 15 hospitals.