Table 3.

Frequent Psychiatric Intervention

Study	Study Design [Sample] Evaluation Period	Definition of FPI	Key Findings
Bagalman et al, 201133	Retrospective study [N=19,191 (BD-I)] 1 year	Having ≥2 clinically significant events during the 12-month identification period (Year 1) after the first observed diagnosis of BD-I. A clinically significant event included ER visits or hospitalizations with a principal diagnosis of BD (any type), addition of a new medication to the first observed treatment regimen, or ≥50% increase in BD medication dose.	In Year 1, prevalence of FPI was 40%. Of patients with FPI in Year 1, 22% also had FPI in Year 2. BD-I patients with FPI (vs without) in Year 1 had greater mental health-related costs ($9132 vs $4521 PPPY) and all-cause costs ($19,446 vs $12,913 PPPY) in Year 2. Patients with FPI (vs without) in Year 1 had significantly more mental health-related hospitalizations (14.6% vs 2.8%) in Year 2 with a longer mean length of stay (11.7 vs 8.2 days; all p<0.001).
Durden et al, 201034	Retrospective study [N=5527 (BD-I)] 1 year		In Year 1, prevalence of FPI was 53%. Of patients with FPI in Year 1, 29% also had FPI in Year 2. BD-I patients with FPI (vs without) in Year 1 had higher adjusted mental health-related ($8299 vs $4823 PPPY) and all-cause costs ($15,699 vs $11,239 PPPY) in Year 2. In Year 2, patients with FPI had 3.7-times greater odds of mental health-related hospitalization and 3.1-times greater odds of mental health-related ER visit than patients without FPI.
Haskins et al, 201039	Retrospective study [N=632 (BD-I or BD-II)] 7 years, max	Having ≥4 clinically significant events requiring intervention in any 12-month period. A clinically significant event was defined as a BD-related ER visit, inpatient psychiatric hospitalization, or a change in psychotropic medication associated with psychiatric symptoms.	In Year 1, prevalence of FPI was 52.5%. BD patients with FPI (vs without) in Year 1 had higher mental health-related costs ($15,189 vs $6374 PPPY) in Year 2. Inpatient hospitalization accounted for the greatest percentage of direct mental health-related costs (43.7% of total direct costs) for patients with FPI in Year 2. Mean days hospitalized were greater for the patients with FPI (5.5 days) compared to those without FPI (1.7 days; p=0.0001).

Notes: All three studies identified patients who had FPI over a 12-month period (Year 1) and examined health care costs for these patients over the subsequent 12-month period (Year 2) relative to patients without FPI. Costs adjusted to 2018 US dollars.

Abbreviations: BD, bipolar disorder; BD I, bipolar I disorder; BD II, bipolar II disorder; ER, emergency room; FPI, frequent psychiatric interventions; max, maximum; PPPY, per patient per year.