Table 1.

Descriptive Characteristics of the Sample

Total	N 552	% 100
Sex
Female	311	56.3
Male	241	46.3
Race/Ethnicity
White, Non-Hispanic	424	76.8
Black, Non-Hispanic	70	12.7
Hispanic	60	10.9
Asian	21	3.8
Native Hawaiian / Pacific Islander	1	0.2
Other	21	3.8
Age
18–39	164	29.7
40–64	231	41.8
65+	157	28.4
Primary diagnosis
Bipolar I disorder	296	53.6
Bipolar II disorder	76	13.7
Unspecified Bipolar disorder /Bipolar disorder not otherwise specified	180	32.6
Comorbid medical conditions1
Cardiovascular disease	361	65.4
Fluid or electrolyte disorder	230	41.7
Anemia	171	31.0
Neurological disorder	136	24.6
Chronic Obstructive Pulmonary Disease	134
		24.3
Elixhauser comorbidity index2
≥10	181	32.8
6–9	104	18.8
≤5	151	27.3
Substance use disorder
Drug abuse	141	28.6
Alcohol abuse	84	15.2
Nicotine use	102	18.4
Transfer from medicine to psychiatry	201	36.4

¹Rates of common comorbid conditions are presented in further detail in Supplementary Figure 1.

²Elixhauser comorbidity index is condensed to a single numeric score that summarizes disease burden using the Van Walraven system (29). This score discriminates risk of in-hospital mortality. Scores ≤ 5 correspond to an in-hospital mortality risk of approximately 0-5%, scores 6–9 a mortality risk of approximately 5–10%, and scores ≥ 10 a mortality risk of greater than 10%. This score was unable to be calculated for N=116 due to missing data.