Background: This paper describes changes in Parkinson's disease (PD) mortality in England and Wales between 1993 and 2006 using all information on death certificates.

Methods: Information on deaths was obtained from the Office for National Statistics. Mortality rates for any mention of PD on death certificates were directly age-standardized using the European standard population. Average yearly changes in mortality rates were estimated using linear regression. The underlying cause of death on death certificates where PD was mentioned was examined by sex and calendar period.

Results: Male PD age-standardized mortality rates for any mention of PD decreased from 15.0 to 11.7 per 100 000 between 1993 and 2006. Female PD mortality rates fell from 6.3 to 4.9 per 100 000. Decreases were greater for older age-groups. The proportion of deaths with PD recorded as the underlying cause increased by 50% in 2001 following implementation of the 10th revision of the International Classification of Diseases (ICD).

Conclusion: Parkinson's disease mortality rates in England and Wales are decreasing, especially for men and for older age-groups. Because of data limitations we are unable to ascertain whether the decrease of PD recorded on death certificates is because of a reduction in PD incidence, or to improved survival for PD patients resulting from advancements in PD treatments or to improvements in general medical care. The dramatic increase in PD as the underlying cause of death following ICD revision in 2001 demonstrates the dangers of using underlying cause of death to investigate mortality trends without being aware of the potential for artifacts.