Characteristic | Smokefree signs [95% CI] | Dog control signs [95% CI] | P-value for difference |
---|---|---|---|
Playgrounds with any sign (N) | 28 | 20 | – |
% of all playgrounds with any sign | 44% (28/63) | 32% (20/63) | 0.149 |
Local government areas with any signs (n = 21 areas) | 71% | 48% | 0.133 |
Playgrounds in city areas (n = 39) with signs | 49% | 36% | 0.264 |
Playgrounds in other local government areas (n = 24) | 38% | 25% | 0.373 |
Total signs (ie, multiple signs in some playgrounds) | 50 | 28 | – |
Mean number of signs per playground (SD) | 0.79 (1.23) | 0.44 (0.80) | 0.095 |
Range for signs per playground (N) | 0 to 6 | 0 to 4 | – |
Sign size | |||
Average in cm2 (SD) | 1057 (960) | 1154 (1161) | 0.749 |
Median in cm2 | 600 | 768 | – |
Inter-quartile range (cm2) | 233 to 1800 | 440 to 1350 | – |
Full range (cm2) | 42 to 2880 | 100 to 3600 | – |
Performance of GSV (using field observations as the gold standard) | |||
Play equipment not visible on GSV (too far from a road) – these results excluded from further analysis | 11 (17.5%) | 11 (17.5%) | – |
True positives [A] | 4 | 7 | – |
True negatives [B] | 26 | 32 | – |
False positives [C]a | 1 | 3 | – |
False negatives [D] | 21 | 10 | – |
Sensitivity [A/(A + D)] | 16% [5% – 34%] | 41% [20% – 65%] | 0.087 |
Specificity [B/(B + C)] | 96% [83% – 100%] | 91% [78% – 98%] | 0.505 |
Positive predictive value [A/(A + C)] | 80% [33% – 99%] | 70% [38% – 92%] | 0.747 |
Negative predictive value [B/(B + D)] | 55% [41% – 69%] | 76% [62% – 87%] | 0.043 |