Death certificate data and causes of death in patients with parkinsonism.

Introduction: Assessment of variables related to mortality in Parkinson disease (PD) and other parkinsonian syndromes relies, among other sources, on accurate death certificate (DC) documentation. We assessed the documentation of the degenerative disorder on DCs and evaluated comorbidities and causes of death among parkinsonian patients.

Methods: Demographic and clinical data were systematically and prospectively collected on deceased patients followed at a tertiary movement disorder clinic. DCs data included the documentation of parkinsonism, causes, and place of death.

Results: Among 138 cases, 84 (60.9%) male, mean age 77.9 years, mean age of onset 66.7, and mean disease duration 10.9 years. Clinical diagnoses included PD (73.9%), progressive supranuclear palsy (10.9%), multiple system atrophy (7.2%), Lewy body dementia (7.2%) and corticobasal degeneration (0.7%). Psychosis occurred in 60.1% cases, dementia in 48.5%. Most PD patients died due to heterogeneous causes before reaching advanced stages. Non-PD parkinsonian patients died earlier due to causes linked to the advanced neurodegenerative process. PD was documented in 38.4% of DCs with different forms of inconsistencies. That improved, but remained significant when it was signed by a specialist.

Conclusions: More than half of PD cases died while still ambulatory and independent, after a longer disease course and due to causes commonly seen in that age group. Deaths among advanced PD patients occurred due to causes similar to what we found in non-PD cases. These findings can be useful for clinical, prognostic and counseling purposes. Underlying parkinsonian disorders are poorly documented in DCs, undermining its' use as sources of data collection.