Clinical characteristics and resource utilization of patients with bipolar disorder who have frequent psychiatric interventions

Figures & data

Table 1.  2008 unit costs of psychiatric resources.

Annual per-patient costs	2004 unit cost from Stensland et al.13 (US$)	Inflated 2008 unit cost (US$)*
Direct medical costs
ER visits	512.50	614.95
Days of hospitalization	751.27	901.45
Outpatient visits	70.87	85.04
Medications
All antipsychotics	1439.53	1604.42
Antidepressants	618.18	688.99
Anticonvulsants	1045.28	1165.01
Lithium	115.00	128.17
Benzodiazepines	92.50	103.10

*Costs inflated to 2008 on the basis of United States Bureau of Labor Statistics consumer price index14,15.

Figure 1.  Baseline CGI-S ratings at first visit for patients who required FPIs vs. those who did not require FPIs. CGI-S, Clinical Global Impressions–Severity; FPIs, frequent psychiatric interventions. N = 610 (FPIs, n = 325; no FPIs, n = 285).

Table 2.  Comparison of baseline demographics, medication use and suicidality in patients with or without FPIs.

	Total patient population (n = 632)	Patients with FPIs
		Yes (n = 332)	No (n = 300)	p-value*
Age, mean (SD), years	40.5 (12.4)	39.1 (11.4)	42.2 (13.2)	0.0015
Gender, n (%)
Male	250 (39.6)	112 (33.7)	138 (46.0)	0.0016
Female	382 (60.4)	220 (66.3)	162 (54.0)
Race, n (%)†
Caucasian	431 (68.4)	218 (65.9)	213 (71.2)	0.0045‡
African American	127 (20.2)	81 (24.5)	46 (15.4)
Other	72 (11.4)	32 (9.7)	40 (13.4)
Suicidality, n (%)	298 (47.2)	208 (62.7)	90 (30.0)	<0.0001
Resource utilization, visits per patient
ER	1.4	2.2	0.5	0.0001
Inpatient days§	3.7	5.5	1.7	0.0001
Outpatient visits	18.1	24.4	11.0	0.0001
Psychotropic medications per visit, mean (SD)	2.7 (1.2)	2.9 (1.1)	2.3 (1.2)	<0.0001
Non-psychotropic medications per visit, mean (SD)	2.2 (2.3)	2.5 (2.5)	1.9 (2.0)	0.0025

ER, emergency room; FPIs, frequent psychiatric interventions; SD, standard deviation.

*p-value corresponds to patients who have FPIs versus those who do not have FPIs.

†N = 630 (FPIs, n = 331; no FPIs, n = 299).

‡p-value corresponds to comparison of African American patients and Caucasian patients, plus others.

§Daily inpatient assessments of a patient by a physician were equated with days of inpatient hospitalization.

Table 3.  Concomitant medications with statistically significant use in patients with or without FPIs*.

Medication, n (%)	Patients with FPIs
	Yes (n = 332)	No (n = 300)	p-value
Antipsychotics
Typical	33 (9.9)	12 (4.0)	0.0037
Atypical	238 (71.7)	112 (37.3)	<0.0001
Antimania
Lithium	152 (45.8)	91 (30.3)	<0.0001
AEDs	188 (56.3)	136 (45.3)	0.0046
AEDs, second generation	169 (50.9)	84 (28.0)	<0.0001
Antidepressants
Atypicals	195 (58.7)	119 (39.7)	<0.0001
TCAs	33 (9.9)	12 (4.0)	0.0037
SNRIs	93 (28.0)	36 (12.0)	<0.0001
SSRIs	224 (67.5)	133 (44.3)	<0.0001
Anxiolytics
Benzodiazepines	220 (66.3)	129 (43.0)	<0.0001
Non-benzodiazepines	42 (12.7)	19 (6.3)	0.0072
Anti-sedation	15 (4.7)	5 (1.7)	0.0409
Extrapyramidal symptoms, Parkinson’s disease	28 (8.4)	10 (3.3)	0.0071
Amphetamines	55 (16.6)	27 (9.0)	0.0047
Selective GABA-receptor agonists	28 (8.4)	8 (2.7)	0.0018
Alcohol abuse	9 (2.7)	2 (0.7)	0.0497

AED, antiepileptic drug used as a mood stabilizer; FPIs, frequent psychiatric interventions; GABA, gamma-aminobutyric acid; SNRI, selective norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclic antidepressant.

*Concomitant medications that were commonly used in patients with and without FPIs but not statistically significant between the two populations were medications used for opioid addiction (5.4% vs. 3.0%; p = 0.132), tremor/akathisia (4.5% vs. 2.7%; p = 0.214) and medications for insomnia (benzodiazepines: 4.2% vs. 3.7%; p = 0.723; non-benzodiazepines: 4.8% vs. 3.0%; p = 0.241).

Table 4.  Psychiatric and substance abuse co-morbidities that were statistically significant in patients with and without FPIs*.

Co-morbidity, n (%)	Patients with FPIs
	Yes (n = 332)	No (n = 300)	p-value
Anxiety disorders	134 (40.4)	77 (25.7)	<0.0001
Depressive disorders	128 (38.6)	71 (23.7)	<0.0001
Mood, other†	38 (11.5)	11 (3.7)	0.0003
Schizophrenia	9 (2.7)	2 (0.7)	0.0497
Psychotic disorders, other‡	38 (11.5)	12 (4.0)	0.0005
Substance abuse diagnosis	132 (39.8)	84 (28.0)	0.0019
Alcohol use disorders	81 (24.4)	53 (17.7)	0.0387
Cocaine use disorders	60 (18.1)	31 (10.3)	0.0057
Nicotine use disorders	28 (8.4)	8 (2.7)	0.0018
Poly-substance use	13 (3.9)	1 (0.3)	0.0022
Personality disorders	106 (31.9)	30 (10.0)	<0.0001
Eating disorders	9 (2.7)	1 (0.3)	0.0168
Dissociative disorders	6 (1.8)	0 (0)	0.0193
Relational problems	52 (15.7)	12 (4.0)	<0.0001
Additional codes§	169 (50.9)	97 (32.3)	<0.0001
Additional conditions that may be a focus of clinical attention¶	27 (8.1)	13 (4.3)	0.0501

FPIs, frequent psychiatric interventions.

*Psychiatric or substance abuse co-morbidities commonly found in patients with and without FPIs, with no significant difference between the two populations, were attention-deficit and disruptive behavior disorders (10.8% vs. 8.7%; p = 0.358), adjustment disorders (4.5% vs. 3.0%; p = 0.319), cannabis abuse (12.4% vs. 8.7%; p = 0.133) and opioid abuse (5.7% vs. 5.3%; p = 0.831).

†Mood Disorder Due to General Medical Condition and Mood Disorder NOS.

‡Brief Psychotic Disorder, Delusional Disorder, Psychotic Disorder Due to General Medications, Psychotic Disorder NOS, Schizoaffective Disorder, Schizophreniform Disorder, Shared Psychotic Disorder.

§Diagnosis or Condition Deferred on Axis, No Diagnosis on Axis II, No Diagnosis or Condition on Axis I, Unspecified Mental Disorder (Nonpsychotic).

¶Academic Problem, Acculturation Problem, Adult Antisocial Behavior, Age-Related Cognitive Decline, Bereavement, Child or Adolescent Antisocial Behavior, Identity Problem, Malingering, Non-Compliance With Treatment, Occupational Problem, Phase of Life Problem.

Table 5.  Annual per-patient direct psychiatric medical and pharmacy costs in patients with and without FPIs.

Annual psychiatric costs	Patients with FPIs
	Yes (n = 332) (US$)	No (n = 300) (US$)
Direct psychiatric medical costs
ER visits	1371	299
Inpatient hospitalization	4982	1505
Outpatient visits	2078	937
Total direct psychiatric medical costs	8431	2742
Psychiatric pharmacy costs
All antipsychotics	1165	626
Antidepressants	610	487
Anticonvulsants	1081	850
Lithium	59	39
Benzodiazepines	68	46
Total psychiatric pharmacy  medication costs	2983	2048
Overall total direct psychiatric cost per year (direct medical costs plus pharmacy costs)	11,414	4790

FPIs, frequent psychiatric interventions.

Table 6.  Variables associated with FPIs (multivariate analysis).

Variable	OR	95% CI	p-value*
Only demographic factors included in the model
Age, years (≥40 vs. <40)	0.750	0.568–1.077	0.132
Race, African American (yes vs. no)	1.564	1.036–2.362	0.033
Gender, female (yes vs. no)	1.595	1.149–2.214	0.005
All factors included in the model
Age, years (≥40 vs. <40)	0.950	0.666–1.355	0.776
Race, African American (yes vs. no)	1.145	0.717–1.829	0.570
Gender, female (yes vs. no)	1.288	0.897–1.849	0.171
Depressive disorders (yes vs. no)	1.373	0.930–2.026	0.111
Anxiety disorders (yes vs. no)	1.317	0.892–1.943	0.166
Personality disorder (yes vs. no)	2.675	1.666–4.296	<0.0001
Relationship problems (yes vs. no)	2.818	1.408–5.642	0.0034
Substance abuse (yes vs. no)	1.077	0.732–1.584	0.708
Baseline CGI-S score (≥5 vs. <5)	1.148	0.991–1.331	0.066
Suicidality (yes vs. no)	2.561	1.764–3.720	<0.0001

CGI-S, Clinical Global Impressions–Severity; CI, confidence interval; FPIs, frequent psychiatric interventions; OR, odds ratio.

*Calculated using chi-square test.

Stensland MD, Jacobson JG, Nyhuis A. Service utilisation and associated direct costs for bipolar disorder in 2004: an analysis in managed care. J Affect Dis 2007;101:187-193

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