1. ONS Mortality Data Adjusting for the impact of coding changes in PHE Jo Watson, PHE

2. Why adjust? Dual coding exercise 2012 registrations – 95% deaths remained in same chapter but statistically significant % increases in 7 chapters & stat sig % decreases in 5 chapters Need to produce cause-specific mortality trends that are comparable over time 2ONS Mortality Data - Adjusting for the impact of coding changes in PHE

3. What PHE have done previously Earlier change affected deaths from 2011 onwards PHE production of comparability ratios to allow adjustment of cause of death data with guidance 419 comparability ratios split by age and sex produced for the 2011 change with 95% confidence intervals – published at: http://www.apho.org.uk/resource/item.aspx?RIS=1 26646 3ONS Mortality Data - Adjusting for the impact of coding changes in PHE

4. What PHE are doing this time Bridge coded data from ONS used to produce CRs for almost all the same cause groups as for the 2011 change. Four sets of ratios to be published with 95% CIs: For all persons/all ages By broad age group (<75, 75+) By sex By sex and broad age group Consistent with previous method 4ONS Mortality Data - Adjusting for the impact of coding changes in PHE

5. No. & % of significant ratios Note data are provisional 5ONS Mortality Data - Adjusting for the impact of coding changes in PHE Significant ratios Count of all ratios % No split (all persons/ages) 4612936% Split by age6022027% Split by male/female 7024828% Split by age/sex 10041924%

6. Adjusting trend data Ratios calculated for the change applied back to data for 2011 Prior to 2011, two sets of ratios need to be applied 6ONS Mortality Data - Adjusting for the impact of coding changes in PHE

7. Example of how to adjust trend data Year Reported numbers Comparability ratio for 2011 coding change Adjustment for coding change in 2011 Comparability ratio for 2014 coding change Adjustment for coding change in 2014 2009164251.58259031.0727738 2010183491.58289371.0730988 201130256 1.0732400 201234998 1.0737478 201337327 1.0739972 201440200 7ONS Mortality Data - Adjusting for the impact of coding changes in PHE Dementia deaths (ICD-10 F01, F03) England and Wales, 2009-13

8. Impact of adjusting 8ONS Mortality Data - Adjusting for the impact of coding changes in PHE Dementia deaths trend with adjustments (ICD-10 F01, F03) England and Wales, 2009-13

9. Attributable fractions 9ONS Mortality Data - Adjusting for the impact of coding changes in PHE CRs to be calculated for any indicators based on grouped causes of death e.g. alcohol-specific deaths For indicators calculated with attributable fractions, however, ratios should be applied to each of the individual cases

10. Next steps 10ONS Mortality Data - Adjusting for the impact of coding changes in PHE QA comparability ratios Publication of comparability ratios with associated guidance documents Adjustments to be applied to all relevant years and to all causes of death currently published in PHOF New data released as part of November 2015 update