Skip to main content
. 2017 Aug 28;27(1):21–30. doi: 10.1136/bmjqs-2017-006607

Table 3.

Size of variation, and proportions of observed variance explained by chance and/or age-sex differences between practice populations. Note that the per cent of variance explained is on the log/log odds, respectively, as opposed to the natural scale

Column 1 Column 2 Column 3 Column 4 Column 5 Column 6 Column 7 Column 8 Column 9 Column 10 Column 11
Diagnostic process or outcome indicators Number of practices included Per cent of variance due to chance alone Per cent of variance due to practice age-sex profile (beyond role of chance) Per cent of variance due to both chance and practice age-sex profile Observed (actually reported) 75th/25th RR/OR Adjusted for chance 75th/25th RR/OR Adjusted for chance and practice age-sex profile 75th/25th RR/OR Observed (actually reported) 90th/10th RR/OR Adjusted for chance 90th/10th RR/OR Adjusted for chance and practice age-sex profile
90th/10th RR/OR
Process indicators
 Breast screening coverage 7951 9.5 53.8 58.2 1.82 1.75 1.46 3.03 2.90 2.06
 Cervical screening coverage 7910 6.9 46.0 49.8 1.54 1.57 1.39 2.36 2.37 1.88
 Bowel screening coverage 7924 13.9 75.3 78.8 1.78 1.70 1.30 2.92 2.74 1.65
 Sigmoidoscopy rate 7954 31.1 24.9 48.3 1.99 1.93 1.77 4.22 3.52 2.97
 Colonoscopy rate 7954 37.8 38.6 61.8 1.81 1.76 1.56 3.26 2.96 2.34
 Upper gastrointestinal endoscopy rate 7954 26.5 33.9 51.4 1.67 1.70 1.54 2.85 2.74 2.27
 TWW referral rate 7954 19.6 39.9 51.7 1.86 1.92 1.66 3.56 3.46 2.62
 TWW referral rate (colorectal) 7954 34.1 41.4 61.4 2.36 2.17 1.81 6.44 4.40 3.11
 TWW referral rate (lung) 7954 40.4 25.0 55.3 2.92 2.03 1.85 12.56 3.87 3.23
 TWW referral rate (skin) 7954 27.1 31.9 50.3 2.67 2.45 2.10 8.59 5.55 4.11
 TWW referral rate (breast) 7954 45.0 20.1 56.1 1.98 1.78 1.68 4.07 3.02 2.69
Outcome indicators
 TWW conversion rate 7954 64.8 30.6 75.6 1.92 1.55 1.44 3.93 2.31 2.01
 TWW detection rate 7941 78.4 4.9 79.5 1.98 1.43 1.42 4.25 1.99 1.95
 Emergency route to diagnosis 7687 82.8 30.1 88.0 2.15 1.39 1.32 5.09 1.89 1.70
 Referred route to diagnosis 7687 85.0 7.4 86.1 1.92 1.32 1.30 3.64 1.69 1.66
 Other route to diagnosis 7687 74.8 12.5 77.9 2.13 1.50 1.47 5.11 2.18 2.08

RR, risk ratio; OR, odds ratio;

TWW, two-week wait.