Under-coding of dementia and other conditions indicates scope for improved patient management: A longitudinal retrospective study of dementia patients in Australia.

BACKGROUND

Under-coding of dementia during hospitalisation results in an inability to identify all patients with dementia using hospital administrative data. Clinical coding can be viewed as a proxy for management; therefore, under-coding indicates dementia was not considered in the patient's management. While under-coding of dementia is well established, there is sparse evidence on whether dementia is coded in subsequent hospitalisations among patients with a known diagnosis.

OBJECTIVE

(a) To describe patterns of dementia coding over 5 years after a first-coded (i.e. index) admission for dementia; (b) to identify factors associated with clinical coding of dementia; and (c) to identify patient subgroups at risk of not being coded to inform future interventions to improve hospital identification and management of dementia.

METHOD

Retrospective study of longitudinal hospital data from 1 July 2006 to 30 June 2015 for 7919 patients hospitalised during the 5 years' post-index admission for dementia in a regional local health district of New South Wales, Australia.

RESULTS

Dementia was coded in 63.9% of admissions in the 12 months following index admission for dementia; this decreased to 53.7% after 5 years. Patients were 20% more likely to have dementia actively managed when it co-occurred with delirium. Under-coding varied across conditions, with dementia more likely to be coded in admissions for falls and pneumonitis, and less likely for heart failure, pneumonia and urinary tract infection (UTI).

CONCLUSION

The frequency with which dementia was not coded highlights opportunities to improve identification and management of dementia through dementia-specific care, enhanced clinical protocols, and interventions focused around heart failure, pneumonia and UTI admissions.