more generally in england the mortality rate from dementia and alzheimer s disease has increased steadily since reflecting several factors such as increased awareness of dementia historical nhs policies encouraging gps to diagnose and changes in death certification practices phe b phe c ons d coding changes from also led to increased recording of dementia and alzheimer s disease on death certificates with deaths reallocated from some groups including cerebrovascular disease and pneumonia eg deaths from vascular dementia would once have been coded to circulatory disease but are now coded to dementia phe c campbell this along with the examples given earlier in relation to influenzapneumonia suggests that death certification practices have changed in recent years with some deaths being classified as dementia that would not have been in the past