|
Characteristic
| |
Purchasing prevalence (% households)
|
|---|
|
2009
|
2015/16
|
Absolute difference
|
Relative change (%)
|
Diff. p-value
|
|---|
|
Soft drinks (taxed in 2013)
|
Total
|
All
|
51.3 (48.3 to 54.3)
|
40.4 (37.3 to 43.5)
|
−10.9 (−15.2 to −6.5)
|
−21.2 (−28.7 to − 13.4)
|
< 0.001
|
|
Age
|
Adults only
|
45.8 (41.3 to 50.4)
|
34.4 (28.2 to 40.6)
|
−11.4 (−19.1 to −3.7)
|
−24.9 (−40.1 to −9.0)
|
0.004
|
|
Adults and children
|
53.2 (49.7 to 56.7)
|
42.8 (39.1 to 46.4)
|
−10.5 (−15.5 to −5.4)
|
−19.6 (−28.1 to − 10.8)
|
< 0.001
|
| |
p-value
| | |
0.835
| | |
|
Income tertile
|
Lowest
|
46.9 (42.0 to 51.7)
|
32.6 (27.2 to 38.0)
|
−14.3 (−21.5 to −7.0)
|
−30.4 (−43.6 to − 16.5)
|
< 0.001
|
|
Middle
|
51.0 (46.8 to 55.1)
|
45.5 (40.7 to 50.2)
|
−5.5 (−11.9 to 0.8)
|
− 10.8 (−22.4 to 1.3)
|
0.087
|
|
Highest
|
56.0 (51.6 to 60.3)
|
41.8 (37.1 to 46.5)
|
−14.1 (−20.6 to −7.7)
|
−25.3 (−35.3 to − 14.8)
|
< 0.001
|
| |
p-value
| | |
0.980
| | |
|
Island
|
Outer islands
|
35.1 (30.7 to 39.5)
|
23.1 (18.5 to 27.7)
|
−12.0 (−18.3 to −5.6)
|
−34.1 (−49.1 to − 18.0)
|
< 0.001
|
|
Tongatapu (main island)
|
58.6 (54.7 to 62.4)
|
47.2 (43.3 to 51.2)
|
−11.3 (−16.9 to −5.8)
|
−19.4 (−27.8 to −10.6)
|
< 0.001
|
| |
p-value
| | |
0.886
| | |
|
Milk
|
Total
|
All
|
29.9 (27.3 to 32.4)
|
44.5 (40.7 to 48.4)
|
14.6 (10.0 to 19.3)
|
49.0 (31.3 to 67.8)
|
< 0.001
|
|
Age
|
Adults only
|
26.3 (22.1 to 30.4)
|
39.7 (33.8 to 45.7)
|
13.4 (6.2 to 20.7)
|
51.2 (19.9 to 86.4)
|
< 0.001
|
|
Adults and children
|
31.1 (28.0 to 34.3)
|
46.4 (42.1 to 50.7)
|
15.2 (9.9 to 20.5)
|
48.9 (29.3 to 70.0)
|
< 0.001
|
| |
p-value
| | |
0.698
| | |
|
Income tertile
|
Lowest
|
22.9 (19.5 to 26.3)
|
36.2 (30.6 to 41.9)
|
13.3 (6.7 to 19.9)
|
58.0 (25.7 to 93.9)
|
< 0.001
|
|
Middle
|
30.9 (26.7 to 35.1)
|
46.0 (40.5 to 51.4)
|
15.0 (8.2 to 21.9)
|
48.6 (23.2 to 76.9)
|
< 0.001
|
|
Highest
|
35.8 (32.1 to 39.5)
|
49.6 (43.4 to 55.8)
|
13.8 (6.6 to 21.1)
|
38.7 (16.9 to 62.1)
|
< 0.001
|
| |
p-value
| | |
0.913
| | |
|
Island
|
Outer islands
|
18.8 (15.1 to 22.5)
|
27.3 (23.2 to 31.3)
|
8.5 (2.9 to 14.0)
|
44.9 (11.5 to 84.2)
|
0.003
|
|
Tongatapu (main island)
|
34.8 (31.5 to 38.2)
|
51.3 (46.3 to 56.3)
|
16.4 (10.4 to 22.5)
|
47.2 (27.7 to 68.1)
|
< 0.001
|
| |
p-value
| | |
0.055
| | |
|
Bottled water
|
Total
|
All
|
10.4 (8.7 to 12.1)
|
35.0 (31.5 to 38.4)
|
24.6 (20.7 to 28.4)
|
236.5 (176.3 to 306.0)
|
< 0.001
|
|
Age
|
Adults only
|
9.4 (6.8 to 12.0)
|
31.9 (25.5 to 38.2)
|
22.5 (15.7 to 29.4)
|
240 (135 to 375)
|
< 0.001
|
|
Adults and children
|
10.8 (8.7 to 12.8)
|
36.2 (32.6 to 39.8)
|
25.4 (21.3 to 29.5)
|
236 (169 to 316)
|
< 0.001
|
| |
p-value
| | |
0.477
| | |
|
Income tertile
|
Lowest
|
6.2 (4.1 to 8.3)
|
28.4 (23.5 to 33.2)
|
22.1 (16.8 to 27.4)
|
355 (203 to 563)
|
< 0.001
|
| |
Middle
|
9.7 (6.7 to 12.6)
|
33.5 (28.5 to 38.5)
|
23.8 (18.0 to 29.6)
|
246 (141 to 385)
|
< 0.001
|
| |
Highest
|
15.3 (12.1 to 18.4)
|
41.5 (36.1 to 47.0)
|
26.3 (20.0 to 32.6)
|
172 (111 to 246)
|
< 0.001
|
| |
p-value
| | |
0.324
| | |
|
Island
|
Outer islands
|
2.0 (1.0 to 3.1)
|
19.3 (15.6 to 23.0)
|
17.2 (13.4 to 21.1)
|
849 (399 to 1606)
|
< 0.001
|
|
Tongatapu (main island)
|
14.2 (11.7 to 16.6)
|
41.2 (36.7 to 45.7)
|
27.0 (21.9 to 32.1)
|
191 (136 to 255)
|
< 0.001
|
| |
p-value
| | |
0.003
| | |
- All values are survey weighted to be representative of the national Tongan population. Absolute differences were calculated from the difference between the two means, with t-tests used to give the 95% confidence interval (CI) for the absolute difference and the p-value. Percentage change confidence intervals were calculated using the Fieller method [29]. The absolute difference p-value tests the null hypothesis that the absolute changes in outcome were the same in each sub-group, for example comparing the highest and lowest income group. The difference (Diff.) p-value tests for whether there was any evidence against the null hypothesis that there was no change over time between the two surveys. Source: Tonga Department of Statistics
