Pharmacoepidemiology and costs of medications dispensed during pregnancy: A retrospective population-based study

Objective: To describe the pharmacoepidemiology and costs associated with medications dispensed during pregnancy. Design: Pharmacoepidemiological study and cost analysis. Setting: Queensland, Australia. Population: All women who gave birth in Queensland between January 2013 and June 2018. Methods: We used a whole-of-population linked administrative dataset, Maternity1000, to describe medications approved for public subsidy that were dispensed to 255 408 pregnant women. We describe the volume of medications dispensed and their associated costs from a Government and patient perspective. Main outcome measures: Prevalence of medication use; proportion of total dispensings; total medication costs in AUD 2020/21 ($1AUD = $0.67USD/£0.55GBP in December 2022). Results: During pregnancy, 61% (95% CI 60.96–61.29%) of women were dispensed at least one medication approved for public subsidy. The mean number of items dispensed per pregnancy increased from 2.14 (95% CI 2.11–2.17) in 2013 to 2.47 (95% CI 2.44–2.51) in 2017; an increase of 15%. Furthermore, mean Government cost per dispensing increased by 41% from $21.60 (95% CI $20.99–$22.20) in 2013 to $30.44 (95% CI $29.38–$31.49) in 2017. These factors influenced the 53% increase in total Government expenditure observed for medication use during pregnancy between 2013 and 2017 ($2,834,227 versus $4,324,377); a disproportionate rise compared with the 17% rise in women's total out-of-pocket expenses observed over the same timeframe ($1,880,961 versus $2,204,415). Conclusions: Prevalence of medication use in pregnancy is rising and is associated with disproportionate and rapidly escalating cost implications for the Government.