Case identification and healthcare utilization in the years prior to a first mania diagnosis

There is limited evaluation of approaches to identify patients with new onset bipolar affective disorder (BPAD) when using administrative datasets.

Using the Massachusetts All-Payer Claims Database (APCD), we identified individuals with a 2016 diagnosis of bipolar disorder with mania and examined patterns of psychiatric and medical care over the preceding 48 months.

Among 4806 individuals aged 15-35 years with a 2016 BPAD with mania diagnosis, 3066 had 48 months of historical APCD data, and of those, 75 % involved information from ≥2 payors. After excluding individuals with historical BPAD or mania diagnoses, there were 583 individuals whose 2016 BPAD with mania diagnosis appeared to be new (i.e., 34 new diagnoses per 100,000 individuals aged 15-35 years). Most individuals received medical care, e.g., 98 % had outpatient visits, 76 % had Emergency Department (ED) visits, and 50 % had mental health-related ED visits during the 48 months prior to their first mania diagnosis. One-third (37.2 %) had a depressive episode before their initial BPAD with mania diagnosis.

Study was conducted in one state among insured individuals. We used administrative data, which permits evaluation of large populations but lacks rigorous, well-validated claims-based definitions for BPAD. There could be diagnostic uncertainty during illness course, and clinicians may differ in their diagnostic thresholds.

Careful examination of multiple years of patient history spanning all payors is essential for identifying new onset BPAD diagnoses presenting with mania, which in turn is critical to estimating population rates of new disease and understanding the early course of disease.