Financial impact of accurate discharge coding in a liaison psychiatry service

Previous research has shown that patients seen by liaison psychiatry services are a complex and expensive patient group and that the psychiatric co-morbidities of hospital inpatients are poorly attested at discharge for assignment to diagnosis-related groups (DRGs). The aim of this study was to investigate the accuracy of discharge coding in a neuropsychiatry liaison population. We also aimed to establish whether or not, had the correct diagnosis been assigned, additional funding would have been allocated to the hospital.

Diagnostic codes were retrospectively collected from the discharge diagnoses for all inpatients (n=276) referred to the neuropsychiatry liaison service in a university hospital over a 12 month period and these were compared to a consensus diagnosis. Using grouper software, codes were then changed to reflect the consensus diagnoses and DRGs were recalculated to see if the change in diagnosis led to a change in reimbursement for those patients.

Discharge diagnosis and consensus diagnosis were in agreement in 30% of cases. When discharge codes were corrected, patients changed to a higher paying DRG in 28/220 (12.7%) of patients. The increase in costing associated with this change in DRG was €305,349.

According to these results, not only is the complexity of patients seen by psychiatry consult services in general hospitals not reflected in the discharge diagnosis, but, in this sample of patients, the additional complexity would have led to a significant increase in reimbursement to the hospital. Further training of doctors should increase awareness of this important issue.