Hong Kong Cancer Registry, Hospital Authority

The meaning and use of the world age-standardized rate - ASR(World)

The world age-standardized rate, ASR(World), is calculated by summing up the products of the age-specific rates and the World Standard Population of the same age subgroup and expressed per 100,000 populations. It is a summary measure of rates that a population would have if it had a hypothetical (standard) age structure. Standardization is necessary when comparing several populations that differ with age structure or for the same population over time.

One caution needs to be mentioned when using age-standardized rates. The age-adjusting procedure requires the use of a "standard" population. Various standard populations have been used for age-adjusting in different countries. The most widely used has been the World Standard population modified by Doll et al., (1966) from that proposed by Segi (1960). However, the data presented by the Hong Kong Cancer Registry at this website use a new "WHO World Standard" population published in the "WHO World Health Statistics Annual 1997-99" for age-adjusting in most circumstances. Table below shows the earlier standard population together with the new WHO world standard population for purposes of comparison. Please note that the age-standardized rates based on the new "WHO World Standard" population are not comparable to our previous estimates that are based on the earlier standard (Doll et al., 1966). In addition, comparisons with age-standardized rates from other sources are valid only if they use the same new ¨WHO World Standard〃 population for calculations.

Distribution of World Stand Population (in percent)*

Age Group Doll et al. World Standard
(World 1966) WHO World Standard
(World 2000)

0-4
5-9
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85+ 12.00
10.00
9.00
9.00
8.00
8.00
6.00
6.00
6.00
6.00
5.00
4.00
4.00
3.00
2.00
1.00
0.50
0.50 8.86
8.69
8.60
8.47
8.22
7.93
7.61
7.15
6.59
6.04
5.37
4.55
3.72
2.96
2.21
1.52
0.91
0.63

All Ages 100 100

* Source: Age Standardization of Rates: A New WHO Standard, GPE Discussion Paper Series: No. 31, EIG/GPE/EBD, World Health Organization.

Source: Hong Kong Cancer Registry, Hospital Authority

Age Group	Doll et al. World Standard (World 1966)	WHO World Standard (World 2000)
0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74 75-79 80-84 85+	12.00 10.00 9.00 9.00 8.00 8.00 6.00 6.00 6.00 6.00 5.00 4.00 4.00 3.00 2.00 1.00 0.50 0.50	8.86 8.69 8.60 8.47 8.22 7.93 7.61 7.15 6.59 6.04 5.37 4.55 3.72 2.96 2.21 1.52 0.91 0.63
All Ages	100	100