Aripiprazole long-acting injection - a mirror image study of its effects on hospitalisation at one year.

Second generation antipsychotic long-acting injections have a greater cost than older depots. Their cost-effectiveness has yet to be established. We conducted a non-interventional, observational, follow-up of patients prescribed aripiprazole long-acting injection in two centres using a mirror image method. Data were available for 160 patients consecutively prescribed aripiprazole long-acting injection, of whom 30 were not included in the analysis (21 forensic patients, five incomplete data and four lost to follow-up). Of the 130 patients, 66 (51%) remained on aripiprazole long-acting injection at one year. The mean number of bed days in the year following aripiprazole long-acting injection initiation reduced to 22.82/patient (standard deviation [SD]=55.07) from 30.09/patient/year (SD=30.40) over the three years before initiation ( p<0.001). The mean number of admissions fell from 0.71/patient/year (SD=0.55) to 0.45/patient/year (SD=0.93) over the same period ( p<0.001). The median number of bed days in the three years before aripiprazole long-acting injection was 21.67/year; in the year following it was zero. Outcomes were not statistically better in those who remained on aripiprazole long-acting injection at one year compared with those who discontinued. The prescribing of aripiprazole long-acting injection reduces average bed days and admissions compared with prior treatments. The reduction in bed days is of a magnitude that renders aripiprazole long-acting injection broadly cost-neutral.