Skip to main content

Table 2 Incidence rate (IR) and incidence rate ratio (IRR)

From: Real-world effectiveness of long-acting injections for reducing recurrent hospitalizations in patients with schizophrenia

 Non-medicationOral medication aloneLAI medication
Overall
 Observational period (person-years)80,104169,948 5612 
 Outcome event (count)36,72163,390 1478 
1 episode
 Observational period61,884114,631 2895 
 Outcome event22,59332,045 601 
2 episode
 Observational period11,99233,385 1476 
 Outcome event718713,999 401 
3 episode
 Observational period347612,042 635 
 Outcome event31247098 213 
4 or more episode
 Observational period27529889 606 
 Outcome event381710,248 263 
IR
 Overall4.58 (4.47–4.70)3.73 (3.67–3.79) 2.63 (2.39–2.91) 
 1 episode without SGA before2.68 (2.55–2.81)2.21 (2.10–2.32) 1.57 (1.01–2.47) 
 1 episode with SGA before4.28 (4.13–4.43)2.94 (2.87–3.01) 2.15 (1.85–2.50) 
 2 episode5.99 (5.64–6.38)4.19 (4.04–4.36) 2.71 (2.24–3.29) 
 3 episode8.98 (8.03–10.06)5.90 (5.55–6.27) 3.33 (2.51–4.47) 
 4 or more episode13.88 (12.28–15.74)10.36 (9.71–11.07) 4.31 (3.25–5.79) 
 Only oral medication IR/non-medication IRLAI IR/non-medication IR
OverallReference0.81 (0.80–0.83)< 0.0010.57 (0.52–0.63)< 0.001
 1 episodeReference0.77 (0.75–0.78)< 0.0010.57 (0.49–0.66)< 0.001
 2 episodeReference0.70 (0.67–0.73)< 0.0010.45 (0.37–0.55)< 0.001
 3 episodeReference0.66 (0.62–0.70)< 0.0010.37 (0.28–0.50)< 0.001
 4 or more episodeReference0.75 (0.70–0.80)< 0.0010.31 (0.23–0.42)< 0.001
 LAI IR/only oral medication IR
Overall Reference 0.71 (0.64–0.78)< 0.001
 1 episode Reference 0.74 (0.65–0.86)< 0.001
 2 episode Reference 0.65 (0.53–0.79)< 0.001
 3 episode Reference 0.56 (0.43–0.76)< 0.001
 4 or more episode Reference 0.42 (0.31–0.56)< 0.001
  1. LAI long-acting injection, SGA second-generation antipsychotics, (95% confidence interval)
  2. IR incidence rate \(= \frac{\text{re - hospitalization events}}{{10 {\text{person - years}}}}\) (95% confidence interval)
  3. \({\text{Only oral medication IR/non - medication IR}} = \frac{\text{Only oral medication incidence rate}}{\text{Non - medication incidence rate}}\) (95% confidence interval)
  4. \({\text{LAI IR}}/{\text{non - medication IR}} = \frac{\text{LAI incidence rate}}{\text{Non - medication incidence rate}}\) (95% confidence interval)
  5. \({\text{LAI IR/only oral medication IR}} = \frac{\text{LAI incidence rate}}{\text{Only oral medication incidence rate}}\) (95% confidence interval)