Antipsychotic prescribing and drug-related readmissions in multimorbid older inpatients: a post-hoc analysis of the OPERAM population

Background Limited data are available on characteristics associated with antipsychotic use in multimorbid older adults. Aim Primary: to identify patient characteristics associated with antipsychotic prescribing in a multimorbid population of older inpatients with polypharmacy. Secondary: (1) to observe if antipsychotics use during an index hospitalisation was associated with a drug related admission (DRA) within one year, and (2) to describe these cases of antipsychotic-related readmissions. Method This was a secondary analysis of the OPERAM randomized controlled trial. Multivariate analysis assessed the association between characteristics and comorbidities with antipsychotic use. An expert team assessed DRA occurring during the one-year follow-up. Results Antipsychotics were prescribed to 5.5% (n = 110) patients upon admission while 7.7% (n = 154) inpatients received antipsychotics at any time (i.e. upon admission, during hospitalisation, and/or at discharge). The most frequently prescribed antipsychotics were quetiapine (n = 152), haloperidol (n = 48) and risperidone (n = 22). Antipsychotic prescribing was associated with dementia (OR = 3.7 95%CI[2.2;6.2]), psychosis (OR = 26.2 [7.4;92.8]), delirium (OR = 6.4 [3.8;10.8]), mood disorders (OR = 2.6 [1.6;4.1]), ≥ 15 drugs a day (OR = 1.7 [1.1;2.6]), functional dependency (Activities of Daily Living score < 50/100) (OR = 3.9 [2.5;6.1]) and < 2 units of alcohol per week (OR = 2.2 [1.4;3.6]). DRA occurred in 458 patients (22.8%) within one year. Antipsychotic prescribing at any time was not associated with DRA (OR = 1.0 [0.3;3.9]) however contributed to 8 DRAs, including 3 falls. Conclusion In this European multimorbid polymedicated older inpatients, antipsychotics were infrequently prescribed, most often at low dosage. Besides neuro-psychiatric symptoms, risk factors for inhospital antipsychotic prescribing were lower functional status and polymedication.