Long-Acting Injectable Antipsychotics in a Prescription Claims Data Source: A Validation Study

Evaluating the impact of COVID-19 on medication adherence and health care utilization among individuals with psychotic disorders who are prescribed long-acting injectables (LAIs) or clozapine: A population-based study in Manitoba, Canada

BACKGROUND

Ongoing psychiatric follow-up and medication adherence improve outcomes for patients with psychotic disorders. Due to COVID-19, outpatient care may have been disrupted, impacting healthcare utilization.

METHODS

A retrospective population-wide study was conducted for adults in Manitoba, Canada. Medication adherence and healthcare utilization were examined from 2019 to 2021. The presence of a diagnosed psychotic disorder was identified in the five years before the index date in each year. The LAI and clozapine cohorts consisted of those who received at least two prescriptions in each year 180 days before the March 20th index date. The change in adherence was measured using the average Medication Possession Ratio. Healthcare utilization rates were compared using Generalized Estimating Equation models.

RESULTS

There were no significant differences between LAI and clozapine discontinuation rates before and during the pandemic. In the LAI cohort, general practitioner visits decreased significantly (-3.5 %, p = 0.039) across four quarters of 2021 versus 2019. All-cause hospitalizations decreased by 16.8 % in 2020 versus 2019 (p = 0.0055), while psychiatric hospitalizations decreased by 18.7 % across four quarters in 2020 (p = 0.0052) and 13.7 % in 2021 (p = 0.0425), versus 2019 in the LAI cohort. There was a significant transition to virtual care during the first wave of COVID-19 (71 % in clozapine, 51 % in LAI cohorts). Trends in total outpatient visits and non-psychiatric hospitalizations remained stable.

CONCLUSION

COVID-19 had no substantial impact on LAI and clozapine discontinuation rates for patients previously adherent. Outpatient care remained stable, with a significant proportion of visits being done virtually at the outset of the pandemic.

Second-Generation Long-Acting Injectable Antipsychotics and the Risk of Treatment Failure in a Population-Based Cohort

Introduction: Second-generation long-acting injectable antipsychotics (SG-LAIAs) may improve outcomes compared to other antipsychotics. Real-world studies using linked administrative databases play an important role in assessing the comparative effectiveness of antipsychotic medications.

Methods: We used a prevalent new-user design in a population-based cohort of antipsychotic users with diagnosis of a psychotic disorder to compare the primary outcome of treatment failure, defined as psychiatric hospitalization, completed suicide, incarceration, or treatment discontinuation. Additional outcomes were all-cause mortality. SG-LAIA users were matched on a 1:1 basis with other antipsychotic users based on the time-conditional propensity score, calendar time, and prior antipsychotic exposure.

Results: The use of LAIAs was not associated with a lower risk of treatment failure than other antipsychotics (adjusted hazard ratio 1.07 and 95% confidence interval 0.98–1.15) but did reduce all-cause mortality (adjusted hazard ratio 0.69 and 95% confidence interval 0.48–0.99). Monotherapy with LAIAs was superior to other antipsychotic monotherapy (adjusted hazard ratio for treatment failure 0.83 and 95% confidence interval 0.78–0.89), and LAIAs were superior to other antipsychotics in antipsychotic-naïve users (adjusted hazard ratio for treatment failure 0.57 and 95% confidence interval 0.47–0.70).

Conclusion: In this population-based cohort, SG-LAIAs reduced the risk of treatment failure in incident new users but not in prevalent new users.