Objective : To find the effective means to detect adverse drug reactions (ADRs) from hospital information system, three data sources, i.e. diagnosis data (Dx), laboratory data (Lab), and prescription data (Rx), are compared in diuretics induced hyperuricemia and/or gout (H/G).
Design : Retrospective cohort study.
Methods : Cohort entry period was three months. Hypertensive outpatients who already had H/G prior to that period were excluded. Then, they were surveyed for 9 months. The patients using diuretics were separated into two groups, i.e. Thiazide-treated group, and Loop-treated group.
Controls were randomly selected from non-diuretic-treated hypertensive outpatients matched to each diuretic group by age and sex. Signals of ADRs were the new prescription of drugs employed in the treatment of H/G from Rx, abnormal serum uric acid level from Lab, and diagnosis of H/G from Dx. The interrelationship of them were examined by the Venn diagram and scatter plot. Finally the incidence of ADRs detected by the above signals and relative risks were calculated and compared. Moreover, prevalence of renal disease in each group was surveyed to examine the possibility that renal disease caused H/G.
Results : Eighteen patients in 240 outpatients treated with Thiazide diuretics and 70 patients in 523 outpatients treated with Loop diuretics were found having developed H/G from Dx, Lab, and/or Rx data sources. More than 90% of total patients were detected from Lab while, a few patients were identified from Dx and Rx. It was rare and coincidental that the three data sources agreed with one another.
The risk of Loop diuretics is approximately twice that of Thiazide diuretics. The incidence and risk of H/G in diuretics estimated in the current study were compatible with the prior report. However, the prevalence of renal disease were high (though not statistically significant) in Loop-treated group so that we possibly overestimated the risk of it.
Conclusion : The order of three data sources, arranged according to the number of ADR signals detected, was Lab, Rx, and Dx. It may be possible to assess the risk of ADR even by Lab only. If Lab is not available, Rx and Dx are useful provided that more subjects and longer research period are involved. However it is necessary to combine three data sources, Dx, Lab, and Rx to detect as many suspected adverse events as possible when using the present clinical database.