Category: Federal Forum Posters
Purpose: Long-acting injectable antipsychotics (LAI-APs) have been integral in the management of schizophrenia and other psychiatric illnesses, such as schizoaffective disorder and bipolar disorder, in veterans. However, there are no substantial studies comparing LAI-APs with each other, including Risperdal Consta (risperidone, RC) and Invega Sustenna (paliperidone, IS). RC requires a 3-week oral overlap and is administered every 2 weeks, while IS does not require an oral overlap and is administered every 4 weeks. Both LAIs deliver related molecules. This study sought to assess differences in psychiatric hospitalizations, medication nonadherence, and medication discontinuation between RC and IS.
Methods: This IRB-approved retrospective chart review included veterans ≥18 years old who have received at least 2 injections of either LAI-AP (RC or IS) and have received the LAI-AP injections during outpatient and/or inpatient care between 01/01/2016 and 12/31/2018 at VA Loma Linda Healthcare System. De-identified data collected included demographics, diagnoses, comorbid alcohol, nicotine, opioid, and substance use, duration on LAI-AP, medication nonadherence, medication discontinuation, pre and post psychiatric hospitalizations, and direct costs of psychiatric hospitalizations. Nonadherence was defined as missing an injection for a specified duration (>3 days for RC and >7 days for IS). Pre and post LAI-AP hospitalizations were assessed using a pre-post design with equivalent time periods. Descriptive statistics were used. Chi-Square, Fisher’s Exact, and Mann-Whitney U tests were used for statistical analysis and p-value was set at < 0.05 for statistical significance.
Results: Ninety-seven subjects were included in this study (44 on RC and 53 on IS). Subjects had a mean age of 46 ±13.8 years, 92% were male, and 94% were diagnosed with schizophrenia or schizoaffective disorder. Subjects on RC were less likely to be rehospitalized (22.7% vs 47.2, p=0.013), had less post-treatment hospitalizations (0.4 ±1.0 vs 0.9 ±1.5, p=0.015), a larger difference between pre and post LAI-AP hospitalizations (2.8 ±2.9 vs 1.3 ±1.7, d=0.66, p=0.001), a larger difference in incidence per 10 person-years (7.4 vs 3.4, p=0.012), and a higher amount of savings in directs costs of hospitalizations for RC users than for IS users ($5,591 ±$5,715 vs $2,490 ±$3,395, p=0.001) compared to IS. However, subjects on RC had a shorter treatment duration (41.6 ±40.2 vs 58.2 ±45.7 weeks, p=0.043) compared to IS. No statistically significant differences were found in nonadherence rates (25% vs 28.3%, p=0.715) and discontinuation rates (68.2% vs 62.3%, p=0.543) between RC and IS.
Conclusion: Veterans on RC were less likely to be rehospitalized, had less post-treatment psychiatric hospitalizations, a larger difference between pre and post LAI-AP hospitalizations, a larger difference in incidence per 10 person-years, and a higher amount of savings in directs costs of hospitalizations compared to IS. However, subjects on RC had a shorter treatment duration. Medication nonadherence and discontinuation rates were comparable between RC and IS. Future studies that include all VA institutions as well as cost-minimization analyses are warranted.