Case-mix adjusted percentage of cancers diagnosed at stages 1 and 2 in England, 2019

In England, there were 234,967 cancers diagnosed with a valid stage in 2019, which was 76.5% of all stageable cancers. Of these, 54.5% were diagnosed at stages 1 and 2, this is comparable to that of 2018, when the unadjusted percentage of cancers diagnosed at stages 1 and 2 was 54.3%. The range over the period of 2013 to 2019 was 53.9% to 55.6%.

Comparisons between geographies using unadjusted values of the indicator have been shown to be misleading due to differences in the underlying population characteristics and distribution of risk factors. Populations within CCGs consist of a differing mix of people in terms of their characteristics such as age, sex and deprivation. Case-mix adjustment is a process which accounts for differences in these population characteristics when calculating outcomes (e.g. percentage of cancers diagnosed at early stage). This allows for fairer comparisons of outcomes between CCGs that have populations with different characteristics negatively or positively associated with the performance indicator.

There are 21 cancer sites/groups included in the ‘case-mix adjusted percentage of cancers diagnosed at stages 1 and 2’ indicator, with 218,389 cancers diagnosed with a valid stage in 2019. The overall case-mix adjusted percentage of cancers diagnosed at stages 1 and 2 was 54.8% for the most recent 3-year period (2017 to 2019). For the same period, the range of case-mix adjusted percentage of cancers diagnosed at stages 1 and 2 across the 106 CCGs was 50.5% to 58.4%, which is smaller than the unadjusted range (49.0% to 59.7%). This shows that a part of the variation in the percentage of cancers diagnosed at stages 1 and 2 between CCGs is associated with the population characteristics.

The variation of the case-mix adjusted ‘percentage of cancers diagnosed at stages 1 and 2’ indicator by CCG for the most recent 3-years of data (2017 to 2019) is presented in Figure 1. There are no obvious geographical patterns to the CCG variation.

For England, between 2013 to 2015 and 2017 to 2019, the case-mix adjusted percentage of cancers diagnosed at stages 1 and 2 remained stable at 55%. Between 2013 to 2015 and 2017 to 2019, the case-mix adjusted percentage of cancers diagnosed at stages 1 and 2 had not changed significantly for 77 CCGs, had fallen significantly for 13 CCGs, and had risen significantly for 16 CCGs.

Figure 2 shows that the range in the case-mix adjusted percentage of cancers diagnosed at stage 1 and 2 (the gap between the highest and lowest CCGs) has widened from 7.6 percentage points in 2013 to 2015 (51.6% to 59.2%) to 7.9 percentage points in 2017 to 2019 (50.5% to 58.4%). The interquartile range has also increased from 2.2 percentage points in 2013-2015 (53.5% to 55.7%) to 2.3 percentage points in 2017-2019 (53.4% to 55.7%) which means there is now more geographic variation in the percentage of cancers diagnosed at stages 1 and 2 by CCG in England, however, this increase is not statistically significant.

When assessing trends over individual years, the focus should be on overall trends rather than year-on-year variation. This is because the number of cases diagnosed each year in each CCG is relatively small and the estimates are therefore less stable.