25 Aug Data variability across Canadian administrative health databases
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Data variability across Canadian administrative health databases
Overview
What is the aim of the study?
- In this study, we compare the provincial administrative databases and illustrate the potential impact of database differences on a CNODES study about domperidone and the risk of ventricular tachyarrhythmia and sudden cardiac death (VT/SCD).
How was the study conducted?
- We assessed the impact of varying versions and precision of the International Classification of Diseases coding system in physician claims data, and the content and completeness of hospital discharge abstracts across CNODES sites, as these variations can introduce differences in the study cohorts formed and affect study results.
What did the study find?
- In our study of 214 962 patients, hospital diagnosis type (such as most responsible, admitting, or secondary diagnosis) was missing in some provinces, resulting in misclassification of the outcome and variation in rates and risk estimates.
- Incidence rates of VT/SCD ranged from 19.8 (95% confidence interval [CI] 17.7‐22.2) per 10 000 person‐years in British Columbia to 53.4 (95% CI 50.3‐56.5) in Quebec.
- While most provinces reported an increased risk of VT/SCD, a null effect was observed in Quebec (rate ratio 1.06; 95% CI 0.79‐1.41).
Implications
- Distributed analyses allow for rapid responses to drug safety signals. However, variation in characteristics of the administrative data across research centres can influence study results.
- By identifying the sources of database heterogeneity, one can evaluate the potential biases these differences may introduce, highlighting the importance of considering such variation in distributed networks.
key Messages
- The populations and drugs covered by provincial programs, versions and precision of the International Classification of Diseases coding system in physician claims, and content and completeness of hospital discharge abstracts vary across provinces and over time.
- The heterogeneity amongst provincial databases can potentially introduce differences in study cohorts formed and affect study results. By illustrating this heterogeneity, we have emphasized the importance of considering the variability between databases in distributed networks and investigating the impact these differences might have on study results.
Manuscripts
Doyle CM, Lix LM, Hemmelgarn BR, Paterson JM, Renoux C. Data variability across Canadian administrative health databases: differences in content, coding, and completeness. Pharmacoepidemiol Drug Saf. 2020 Jan;29 Suppl 1:68-77.