Clinical Coding Surveillance

Feasibility and Reliability of Clinical Coding Surveillance for Routine Monitoring of Adverse Drug Events in NZ Hospitals

Ng, J; Andrew, P; Muir, P; Greene, M; Mohan, S; Knight, J; et al (2018)

NZMJ. 26 Oct 2018; 131(1484)


The routine measurement of adverse drug events (ADE) is important for monitoring and informing improvement, but current detection tools are manual and too resource intensive. Our research, for the first time, shows ADEs can be reliably and sustainably measured using clinical coding surveillance (CCS). Using CCS, almost 12,000 ADEs over two years were detected in hospitalised patients. Most ADEs originated from the community setting.


AIM: To explore the feasibility and reliability of Clinical Coding Surveillance (CCS) for the routine monitoring of Adverse Drug Events (ADE) and describe the characteristics of harm identified through this approach in a large district health board (DHB).

METHODAll hospital admissions at Waitemata DHB from 2015 to 2016 with an ADE-related ICD10-AM code of Y40-Y59, X40-X49 or T36-T50 were extracted from clinical coded data. The data was analysed using descriptive statistics, statistical process control and Pareto charts. Two clinicians assessed a random sample of 140 ADEs for their accuracy against what was clinically documented in medical records.

RESULTS: A total of 11,999 ADEs were identified in 244,992 admissions (4.9 ADEs per 100 admissions). ADEs were more prevalent in older adults and associated with longer average length of stays and medicines such as analgesics, antibiotics, anticoagulants and diuretics. Only 2,164 (18%) of ADEs were classified as originating within hospital. Of ADEs originating outside of the hospital, the main causes were poisoning by psychotropics, anti-epileptics and anti-parkinsonism agents and non-opioid analgesics. Clinicians agreed that 91% of ADE positive admissions were accurately classified as per clinical documentation.

CONCLUSION: CCS is a feasible and reliable approach for the routine monitoring of ADEs in hospitals.