Technical note on the calculation of the baseline for the Detect Cancer Early HEAT target

5. Calculating the baseline and setting targets

5.1 Following the decision to use audit data for the baseline, the calculation method had to be established. This in turn would inform the national target - to achieve an additional 25% of the baseline proportion of those diagnosed at stage 1.

5.2 It was decided that a two year average would be more appropriate than using a single year to account for variations between years, this is particularly useful for smaller Boards which may experience large percentage changes from small numbers. The DCE priming campaign was launched in February 2012. As such the latest data prior to this would give the best reflection of the proportion of stage 1 cancers before any impact of marketing campaigns or social interventions have been realised (whilst bearing in mind the impact of steadily increasing cancer incidence and the on-going improvements in recording of stage). It was therefore agreed to use data from 2010 and 2011 combined as the baseline. Performance management against the target would then be measured using a rolling two year average i.e. 2011/2012, 2012/2013 etc. through to delivery in 2014/2015.

5.3 As noted previously, audit data was chosen partly because there was a more complete set of staging data available than with registry data. It is unlikely that staging data will be complete for all records within any data set - there will always be cases where stage cannot be determined with certainty or where it is clinically inappropriate to pursue a series of investigations for the sole purposes of determining stage. Following initial work to increase ascertainment of stage in preparation for the 2010/2011 baseline, there remains variation in the level of "unknown" (or unrecorded) stages within the audit data between different NHS boards and across the three cancer types. In order to provide the most comprehensive information it was decided to include these unknown values when reporting the baseline. The impact the inclusion of these "unknowns" had on the measurement against the target was given significant consideration and it was concluded that that their inclusion was important in understanding and reducing the variation in staging information across NHS boards.

5.4 It is expected that the inclusion of these "unknowns" (or unrecorded) will encourage boards to continue to improve the quality of their staging data for all stages - not just stage 1. From quality improvement work that was done for the 2010/2011 baseline it is known that, when staged, some of the "unknowns" become stage 1, some stage 2, etc. Good quality and timely data facilitates transparent demonstration of performance and improvements in patient experience and this will be an additional benefit of the programme.

5.5 The level of variation in the proportion of "unknowns" was taken in to account when setting targets for individual NHS Boards. NHS Boards with a lower proportion of recorded stage 1 cancers tend to have a higher proportion of unstaged data and therefore will have a higher target. All NHS Boards will be expected to reach the same proportion of cancers diagnosed at stage 1 by the end of 2015 and this will be a 25% increase of the published national 2010/2011 baseline.

5.6 There is recognition that geographic, demographic and socio-economic factors will affect regions differently and each board will have a unique challenge in overcoming these to meet their target. The work of the programme will expect boards to find solutions to address inequalities as this will be key to increasing early detection of cancer, for example, by raising the screening uptake figures amongst deprived communities.