Study characteristic | N = 61 | N = 435 | ||
---|---|---|---|---|
N | Correlation (95Â % CI) | N | Correlation (95Â % CI) | |
Year of publication | ||||
 2007 | 12 | 0.854 (0.839–0.867) | 128 | 0.835 (0.830–0.840) |
 2008–2010 | 17 | 0.879 (0.868–0.890) | 98 | 0.873 (0.869–0.877) |
 2011 | 15 | 0.876 (0.864–0.888) | 128 | 0.891 (0.886–0.896) |
 2012–2013 | 17 | 0.895 (0.886–0.904) | 81 | 0.877 (0.873–0.882) |
 |  | p < 0.001 |  | p < 0.001 |
 2007–2010 | 29 | 0.868 (0.859–0.876) | 226 | 0.852 (0.849–0.856) |
 2011–2013 | 32 | 0.888 (0.881–0.895) | 209 | 0.883 (0.880–0.886) |
 |  | p < 0.001 |  | p < 0.001 |
Study design | ||||
 Randomized cross over | 44 | 0.884 (0.878–0.889) | 287 | 0.876 (0.874–0.879) |
 Non–randomised cross over | 3 | 0.825 (0.775–0.865) | 22 | 0.825 (0.807–0.841) |
 Within–patient study | 14 | 0.858 (0.842–0.873) | 126 | 0.828 (0.822–0.833) |
 |  | p < 0.001 |  | p < 0.001 |
 Randomiseda | 45 | 0.884 (0.878–0.889) | 293 | 0.876 (0.874–0.879) |
 Not randomised | 16 | 0.853 (0.837–0.867) | 142 | 0.826 (0.820–0.831) |
 |  | p < 0.001 |  | p < 0.001 |
Platform | ||||
 Paper vs IVRS | 8 | 0.845 (0.824–0.864) | 54 | 0.844 (0.836–0.850) |
 Paper vs PDA | 10 | 0.851 (0.830–0.859) | 69 | 0.851 (0.844–0.859) |
 Paper vs Web/PC | 34 | 0.886 (0.879–0.893) | 197 | 0.863 (0.859–0.866) |
 Paper vs Tablet/touch screen | 7 | 0.890 (0.876–0.902) | 91 | 0.877 (0.872–0.881) |
 Web/PC vs IVRS | 1 | 0.880 (0.841–0.910) | 2 | 0.917 (0.898–0.932) |
 Tablet/touch vs Web/PC | 1 | 0.899 (0.837–0.938) | 22 | 0.917 (0.908–0.926) |
 |  | p < 0.001 |  | p < 0.001 |
Time interval | ||||
 0 (<1 day) | 22 | 0.901 (0.892–0.909) | 223 | 0.890 (0.887–0.893) |
 1 (1–5 days) | 13 | 0.891 (0.882–0.900) | 83 | 0.877 (0.874–0.881) |
 2 (6–14 days) | 19 | 0.852 (0.840–0.864) | 91 | 0.813 (0.805–0.819) |
 3 (15+ days) | 7 | 0.820 (0.791–0.845) | 38 | 0.779 (0.767–0.791) |
 |  | p < 0.001 |  | p < 0.001 |
 0 (<1 day) | 22 | 0.901 (0.892–0.909) | 223 | 0.890 (0.887–0.893) |
 1 (1–9 days) | 26 | 0.881 (0.873–0.888) | 148 | 0.862 (0.859–0.866) |
 2 (10+ days) | 13 | 0.819 (0.799–0.837) | 64 | 0.790 (0.781–0.798) |
 |  | p < 0.001 |  | p < 0.001 |
Mean age of participantsb | ||||
 <28 years | 12 | 0.794 (0.772–0.814) | 80 | 0.789 (0.781–0.796) |
 28–46.9 years | 15 | 0.896 (0.888–0.904) | 98 | 0.875 (0.871–0.878) |
 47–55.9 years | 12 | 0.889 (0.878–0.900) | 103 | 0.877 (0.873–0.881) |
 56+ years | 18 | 0.880 (0.868–0.891) | 141 | 0.886 (0.881–0.891) |
 |  | p < 0.001 |  | p < 0.001 |
Sample size | ||||
 ≤56 | 20 | 0.881 (0.863–0.896) | 126 | 0.885 (0.878–0.891) |
 57–116 | 21 | 0.881 (0.870–0.891) | 184 | 0.866 (0.862–0.870) |
 >116 | 20 | 0.887 (0.870–0.884) | 125 | 0.861 (0.858–0.864) |
 |  | p = 0.817 |  | p < 0.001 |
Publication type | ||||
 Abstract/poster | 10 | 0.898 (0.889–0.906) | 26 | 0.905 (0.900–0.910) |
 Full text publication | 51 | 0.870 (0.864–0.877) | 409 | 0.859 (0.856–0.861) |
 |  | p < 0.001 |  | p < 0.001 |