AP Prescription Patterns

Groups of AP: First-generation agents – FGA (chlorpromazine, promazine, fluphenazine, haloperidol, levomepromazine, sulpiride, zuclopenthixol); Second-generation agents – SGA (risperidone, olanzapine, quetiapine, paliperidone): Third generation agents – TGA (aripiprazole), and Clozapine (separate class as clozapine is the only third line therapy agent with a unique mechanism of action).

Predominant AP group – the AP group prescribed longer and/or in higher daily doses during the observed 6-months period, in comparison to the other prescribed AP groups.

The most commonly prescribed AP – not taking into account the whole prescription pattern (i.e., single use or multiple concurrent AP use).

Mean daily AP dose – the average six-month daily dose (DD) transformed into the olanzapine (OLA) equivalents (19, 20). In cases with more than one AP, their OLA equivalents were summed to obtain the total average AP DD. According to the World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines (9), AP DD above 600 mg chlorpromazine (CPZ) equivalents (19.8 mg OLA equivalents) were considered high maintenance doses. More recently, the Canadian Psychiatric Association – CPA (21) lowered the upper limit of the recommended CPZ equivalent dose from 600 mg/day to 400 mg/day (13.2 mg OLA equivalents). Both WFSBP and CPA thresholds were used in the further considerations.

Route of AP administration – the binary categorical variables (yes/no) described AP formulation delivered over the observed six-month period: (1) Long-acting injectable (LAI) / depot-only – AP only prescribed through depot / LAI formulation; (2) Oral-only – only oral AP formulation was used; (3) LAI / depot-predominantly – LAI / depot prescribed in higher average dose and/or for a longer time period over the observed 6 months in comparison to the oral AP, and 4) Oral-predominantly – oral AP formulation was in higher average dose and/or for a longer time period in comparison to the LAI / depot formulation over the 6-months observation.

Rate of monotherapy vs. polypharmacy – the binary categorical variables (yes/no) described AP drug prescription patterns: (1) long-term AP monotherapy (APM) – AP monotherapy continuously prescribed for at least 6 months, (2) long-term AP polypharmacy (APP) – concurrent continuous use of more than one AP for at least 6 months, (3) uncategorized AP prescription pattern – combined APM/APP prescription during the observational period (the defined criteria for APM/APP were not fulfilled). Long-term add-on therapy – Combinations of AP with other psychotropic drugs (AD/MS/BZD/ACM) continuously prescribed for at least 6 months.