Association between mental disorder and hospitalization outcomes in neurogenic bladder: a retrospective nationwide inpatient sample database study

Abstract

Purpose

We examined the relationship between psychiatric comorbidities—namely depression, anxiety, and combined depression-anxiety—and hospitalization outcomes among patients diagnosed with neurogenic bladder. Using a large, nationally representative database, the study sought to generate evidence for refining clinical guidelines and improving patient management.

Methods

A retrospective study was performed using National Inpatient Sample (NIS) records from 2010–2019, identifying 676,826 adults with neurogenic bladder. Mental health comorbidities were classified through ICD-9/ICD-10 coding for depression (n = 125,654), anxiety (n = 77,730), and depression with anxiety (n = 34,330). Outcomes assessed included hospital length of stay, total charges, in-hospital mortality, and specific urological complications. Descriptive statistics and logistic regression analyses were applied, with adjustments for demographic and hospital-related variables.

Results

Depression, anxiety, and depression-anxiety were found in 13.5%, 6.4%, and 5.1% of cases, respectively, with higher rates among older adults and women. Anxiety was associated with elevated risks of hydronephrosis (OR 1.420), urinary tract infections (OR 1.050), urinary stones (OR 1.511), and acute renal failure (OR 1.246), whereas the odds of cystitis were reduced (OR 0.636). Patients with both depression and anxiety exhibited comparable complication patterns, while depression alone showed no significant associations. Surprisingly, individuals with any of these psychiatric conditions had shorter median hospital stays (5 vs 6 days) and lower mortality (1.8–2.4% vs 3.7%).

Conclusion

Mental health comorbidities in patients with neurogenic bladder are linked to a nuanced spectrum of outcomes. Anxiety increases the risk of several urological complications yet may confer protective effects regarding mortality. These results underscore the importance of systematic psychological assessment and integrated multidisciplinary management in neurogenic bladder care.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11255-025-04913-4.

Introduction

Neurogenic bladder represents a heterogeneous urological disorder that develops when neurological impairments—affecting either the central nervous system (CNS) or peripheral nerves—disrupt normal bladder control [1–3]. Clinical manifestations encompass urinary incontinence, retention, recurrent infections, and sexual dysfunction [4–6]. Data from the Nationwide Emergency Department Sample (NEDS) suggest that, within the U.S. population, the incidence rose from 46.1 per 100,000 individuals in 2006 to 50.9 per 100,000 in 2011, equating to an annual increase of 1.89% (P = 0.017) [7]. In a U.S. claims database study including 46,271 patients with neurogenic bladder from April 2002 to March 2007, upper urinary tract infection occurred in 1.4–2.2%, while severe complications such as sepsis (2.6–4.7%) and acute renal failure (0.8–2.2%) were also observed [8]. On average, individuals with neurogenic bladder attend 16 outpatient visits and 0.5 emergency visits annually, with approximately one-third of the latter resulting in hospitalization [4]. These findings highlight that neurogenic bladder not only contributes substantially to morbidity and mortality but also imposes a significant burden on patients’ quality of life.

Despite diagnostic and therapeutic advances, affected patients continue to experience major physical and psychological burdens [2, 5, 9]. Neurogenic bladder with detrusor overactivity often causes incontinence, which may lead to embarrassment, depression, social withdrawal, pressure ulcers, urethral injury, and upper tract deterioration [10]. Patients with neurogenic lower urinary tract dysfunction (NLUTD) are particularly vulnerable to psychological distress, resulting in isolation, diminished self-esteem, and poorer long-term outcomes [11].

Although the impact of psychiatric comorbidities on in-hospital outcomes has been documented in other urological populations, this relationship remains largely unexplored in individuals with neurogenic bladder. Studies of patients with lower urinary tract dysfunction and urinary incontinence have shown that depression and anxiety are common, contribute to worsening health-related quality of life, and increase healthcare burden, including inpatient utilization and complications [12–14]. Similarly, in patients with bladder and prostate cancer, preexisting mental health illness has been associated with poorer survival outcomes, underscoring the broader prognostic relevance of mental health in urology [15].

To address this gap, we evaluated the impact of psychiatric comorbidities—including depression, anxiety, and their co-occurrence—on hospitalization metrics. Depression and anxiety were selected because they are highly prevalent and clinically significant psychiatric comorbidities frequently reported in association with neurogenic lower urinary tract dysfunction and related urological disorders. Studies in neurological and urological populations have shown that these disorders frequently coexist with urinary symptoms, contribute to greater psychosocial burden, and are associated with reduced adherence to self-care and treatment [16–18]. We compared demographics, length of stay, charges, and complication incidence between patients with and without such comorbidities, leveraging a nationally representative dataset to provide evidence for improved guidelines and management.

Materials and methods

We conducted a retrospective study using NIS (Nationwide Inpatient Sample) data from 2010–2019, one of the largest inpatient datasets provided by the Healthcare Cost and Utilization Project (HCUP). The NIS includes records from approximately 4400 hospitals across 45 U.S. states. Patient, hospital, and state identifiers are anonymized, and because this study utilized publicly available de-identified data, Institutional Review Board approval was not required.

Study population

Adults aged ≥ 18 years with a principal diagnosis of neurogenic bladder (n = 676,826) were identified from the Nationwide Inpatient Sample (NIS) using ICD-9-CM and ICD-10-CM codes. Neurogenic bladder cases were determined based on the concurrent presence of neurological disorders and urinary tract diagnoses, following established approaches used in large-scale NIS studies. [7, 19] Because the NIS does not include a specific variable explicitly indicating neurogenic bladder, all hospitalization records meeting this definition were included to comprehensively capture clinically significant admissions related to neurogenic bladder or its complications. Comorbid psychiatric conditions were identified from secondary diagnosis fields, including depression (n = 125,654), anxiety (n = 77,730), and coexisting depression-anxiety (n = 34,330).

Variables and outcomes

Demographics included age, sex, race, and number of comorbidities. Hospital characteristics comprised insurance type, hospital size, admission type, teaching status, location, and region. Primary outcomes were the occurrence of urological and systemic complications, including hydronephrosis, urinary tract infection, urinary calculi, acute renal failure, and cystitis, as identified through ICD-9/10 codes. Secondary outcomes include hospital length of stay (LOS), total hospitalization charges, and all-cause in-hospital mortality. Psychiatric comorbidities (depression, anxiety, and their co-occurrence) served as key predictor variables for these outcomes. LOS referred to the number of nights hospitalized for neurogenic bladder, while charges excluded professional fees and non-covered items.

Statistical analysis

Categorical data were summarized descriptively, and continuous variables were compared using independent t-tests. Logistic regression models were used to evaluate the associations between psychiatric comorbidities and the primary outcome (complications), adjusting for demographics, comorbidities, and hospital factors. Additional models examined the impact of psychiatric comorbidities on secondary outcomes (LOS, total charges, and mortality). A two-tailed p-value < 0.001 indicated significance. Analyses were performed in SPSS version 26 (IBM Corp., Armonk, NY).

Results

A total of 676,826 neurogenic bladder inpatients were identified. Depression was present in 91,324 (13.5%), anxiety in 43,400 (6.4%), and comorbid depression-anxiety in 34,330 (5.1%).

Older age groups had the highest prevalence: ages 45–64 (30.7–33.2%), 65–74 (21.1–22.5%), and ≥ 75 (28.3–33.5%) compared to 18–44 (12.8–16.3%, p < 0.001). Women predominated in all categories (60.6% anxiety, 56.2% depression, 63.7% comorbid; p < 0.001). By race, White patients had the greatest prevalence (72.8–79.1%). Comorbidities were more common in those with mental disorders, with ≥ 3 comorbidities reported in over 89% of depression and depression-anxiety groups (p < 0.001) (Table 1).

Table 1.

Demographics of patients with neurogenic bladder (2010–2019)

Characteristics	Without mental condition	Anxiety	Depression	Depression comorbid anxiety	p
Total (n = count)	507,772	43,400	91,324	34,330
Total incidence (%)	75.0	6.4	13.5	5.1
Age group (%)
18–44	13.1	16.3	12.8	16.0	< 0.001
45–64	27.0	30.7	32.1	33.2
65–74	20.3	21.1	21.5	22.5
≥ 75	39.5	32.0	33.5	28.3
Gender (%)
Male	53.1	39.4	43.8	36.3	< 0.001
Female	46.9	60.6	56.2	63.7
Race (%)
White	66.1	75.7	72.8	79.1	< 0.001
Black	15.5	9.1	10.9	7.9
Hispanic	8.0	7.0	6.2	5.8
Asian or Pacific Islander	2.3	1.1	1.2	0.8
Native American	0.5	0.5	0.5	0.5
Other	7.6	6.7	8.3	6.0
Number of comorbidity (%)
0	2.1	1.7	0.0	0.0	< 0.001
1	10.5	9.1	1.6	1.6
2	18.2	17.2	9.1	9.0
≥ 3	69.2	72.0	89.3	89.4

Psychiatric groups also had higher rates of chronic pulmonary disease, drug use, hypothyroidism, liver disease, obesity, and psychoses (all p < 0.001). (Table 2)

Table 2.

Comorbidities of patients with neurogenic bladder (2010–2019)

Comorbidities	Without mental condition	Anxiety	Depression	Depression comorbid anxiety	p
Acquired immune deficiency syndrome	1224(0.2%)	118(0.3%)	245(0.3%)	90(0.3%)	0.285
Deficiency anemia	92,441(18.2%)	7123(16.4%)	18,901(20.7%)	5426(15.8%)	< 0.001
Rheumatoid arthritis/collagen vascular diseases	11,451(2.3%)	1285(3.0%)	2648(2.9%)	1061(3.1%)	< 0.001
Chronic blood loss anemia	5721(1.1%)	450(1.0%)	932(1,0%)	345(1.0%)	0.005
Congestive heart failure	72,157(14.2%)	5617(12.9%)	11,917(13.0%)	4416(12.9%)	< 0.001
Chronic pulmonary disease	82,081(16.2%)	10,025(23.1%)	18,306(20.0%)	8333(24.3%)	< 0.001
Coagulopathy	35,356(7.0%)	2609(6.0%)	5385(5,9%)	2050(6.0%)	< 0.001
Diabetes, uncomplicated	99,019(19,5%)	7022(16.2%)	17,977(19.7%)	5599(16.3%)	< 0.001
Diabetes with chronic complications	54,465(10.7%)	4419(10.2%)	9906(10.8%)	3993(11.6%)	< 0.001
Drug abuse	12,967(2.6%)	2458(5.7%)	3207(3.5%)	1924(5.6%)	< 0.001
Hypertension	292,326(57.6%)	26,035(60.0%)	54,761(60.0%)	20,909(60.9%)	< 0.001
Hypothyroidism	71,010(14.0%)	7749(17.9%)	16,806(18.4%)	6743(19.6%)	< 0.001
Liver disease	13,522(2,7%)	1481(3.4%)	2631(2.9%)	1251(3.6%)	< 0.001
Fluid and electrolyte disorders	202,405(39.9%)	16,103(37.1%)	35,242(38.6%)	12,702(37.0%)	< 0.001
Other neurological disorders	193,143(38.0%)	16,373(37.7%)	40,213(44.0%)	13,822(40.3%)	< 0.001
Obesity	52,877(10.4%)	5893(13.6%)	12,398(13.6%)	5665(16.5%)	< 0.001
Paralysis	237,790(46.8%)	19,109(44.0%)	38,682(42.2%)	14,922(43.5%)	< 0.001
Peripheral vascular disorders	32,910(6.5%)	2579(5.9%)	5885(6.4%)	2102(6.1%)	< 0.001
Psychoses	31,987(6.3%)	7226(16.6%)	3768(4.1%)	1649(4.8%)	< 0.001
Pulmonary circulation disorders	14,155(2.8%)	1222(2.8%)	2266(2.5%)	839(2.4%)	< 0.001
Renal failure	82,189(16.2%)	5673(13.1%)	13,179(14.4%)	4571(13.3%)	< 0.001
Peptic ulcer disease excluding bleeding	1656(0.3%)	175(0.4%)	270(0.3%)	168(0.5%)	< 0.001
Valvular disease	26,676(5.3%)	2245(5.2%)	4185(4.6%)	1546(4.5%)	< 0.001
Weight loss	60,464(11.9%)	4759(11.0%)	9992(10.9%)	3695(10.8%)	< 0.001

Median LOS was shorter among patients with anxiety or depression-anxiety (5 days) compared to those without psychiatric conditions (6 days). Corresponding total charges were lower: $34,498 for anxiety, $38,445 for depression, and $36,454 for comorbid depression-anxiety, versus $38,727 in controls (Table 3).

Table 3.

Hospital outcomes of patients with neurogenic bladder (2010–2019)

Characteristics	Without mental condition	Anxiety	Depression	Depression comorbid anxiety	p
LOS (median, d)	6	5	6	5	< 0.001
TOTCHG (median, $)	38,727.00	34,497.50	38,445.00	36,453.50	< 0.001
Type of insure (%)
Medicare	71.7	69.7	72.8	71.1	< 0.001
Medicaid	11.7	13.1	11.5	12.6
Private insurance	12.8	13.9	12.4	13.1
Self-pay	1.6	1.4	1.2	1.1
No charge	0.1	0.1	0.1	0.1
Other	2.1	1.8	2.0	1.9
Bed size of hospital (%)
Small	16.3	17.5	17.0	17.8	< 0.001
Medium	26.8	27.3	26.3	27.9
Large	56.9	55.2	56.7	54.3
Elective admission (%)	88.6	86.9	87.3	87.6	< 0.001
Type of hospital (teaching %)	59.1	60.7	58.3	62.1	< 0.001
Location of hospital (urban, %)	90.0	89.2	88.9	89.7	< 0.001
Region of hospital (%)
Northeast	18.7	17.3	18.0	16.5	< 0.001
Midwest or North Central	22.8	26.1	28.1	30.4
South	39.4	39.8	36.1	38.0
West	19.1	16.8	17.8	15.2
Died (%)	3.7	2.4	2.1	1.8	< 0.001

LOS Length of stay, TOTCHE Total charge

Mortality was reduced in psychiatric groups (2.4% for depression, 2.1% for anxiety, and 1.8% for comorbid) compared with patients without mental disorders (3.7%, all p < 0.001). Most patients were covered by Medicare (69.7–72.8%), and more than half were admitted to teaching hospitals (Table 3).

Regression analysis (Supplementary table) revealed that anxiety increased the odds of hydronephrosis (OR 1.420), UTI (OR 1.050), urinary stones (OR 1.511), and acute renal failure (OR 1.246), but decreased the odds of cystitis (OR 0.636). Patients with comorbid depression-anxiety showed similar increased risks for hydronephrosis, UTI, stones, and renal failure, but no significant difference in cystitis. Depression alone was not significantly linked to these complications (Table 4).

Table 4.

Multivariate logistic regression of complications

Complications	Anxiety group			Depression group			Depression comorbid anxiety group
	OR	95% CI	p	OR	95% CI	p	OR	95% CI	p
Hydronephrosis	1.420	1.346–1.499	< 0.001	1.024	0.955–1.099	0.500	1.179	1.109–1.252	< 0.001
Urinary tract infection	1.050	1.023–1.077	< 0.001	0.961	0.930–0.994	0.019	1.171	1.137–1.206	< 0.001
Urinary calculi	1.511	1.410–1.620	< 0.001	0.948	0.864–1.039	0.255	1.561	1.447–1.684	< 0.001
Acute renal failure	1.246	1.210–1.283	< 0.001	0.970	0.934–1.007	0.110	1.079	1.044–1.115	< 0.001
Cystitis	0.636	0.511–0.793	< 0.001	1.071	0.815–1.409	0.622	0.897	0.699–1.150	0.392

Discussion

Neurogenic bladder dysfunction can arise from congenital anomalies such as myelomeningocele or from neurological conditions including multiple sclerosis, Parkinson’s disease, stroke, spina bifida, and cauda equina syndrome [4].

Our findings that mental disorder comorbidities were associated with increased length of stay and complication rates are consistent with prior literature linking mental health and urological outcomes. Population-based studies have identified bidirectional relationship between depression, anxiety, and lower urinary tract symptoms (LUTS) [20],while systematic reviews have demonstrated a significant association between LUTS and affective disorders. [21, 22] Furthermore, in urological oncology, coexisting psychiatric disorders have been shown to negatively influence functional recovery and survival outcomes [23], highlighting the broad interplay between mental health and urological disease outcomes. In neurological populations specifically, neurogenic LUTS are common and have been associated with both fatigue and depressive symptoms in people with multiple sclerosis [24], supporting a bidirectional relation between symptom burden and psychological distress. Together, these data provide plausible mechanisms by which psychiatric comorbidity may exacerbate urinary morbidity and thereby may contribute to worse inpatient outcomes among patients with neurogenic bladder.

Our study demonstrated clear age-related trends: psychiatric disorders were more frequent in patients aged 45–64 and ≥ 75, with prevalence roughly double that of younger adults. This aligns with literature showing that older adults often face greater difficulty adapting to chronic disease due to established routines, cumulative comorbidities, functional decline, and limited social support [25, 26].

Female patients were disproportionately represented across all categories. Prior work has similarly shown higher depression rates in women with neurogenic bladder after spinal cord injury [27]. Socioeconomic disparities, caregiving roles, and coexisting conditions likely contribute [25, 28]. Biological mechanisms, such as hormonal fluctuation and heightened pain perception in bladder disorders, may also play a role [29, 30]. Moreover, gender bias in healthcare—where women report being dismissed or misdiagnosed more often—can worsen psychological distress [29].

Racial disparities were evident: White patients were more frequently diagnosed with mental disorders, consistent with reports that minorities face reduced access to mental healthcare and greater misdiagnosis risk [31–33].

Patients with psychiatric conditions carried a heavier comorbidity burden, corroborating findings that psychological distress correlates with chronic diseases [20–22].

Interesti

ngly, LOS and costs were lower in anxiety and depression-anxiety groups. Prior studies have proposed that insurance incentives and integrated care models may partly explain such findings [34, 35]. Reduced mortality in psychiatric groups also challenges expectations, possibly reflecting heightened medical surveillance and earlier intervention [36].

Mechanistically, anxiety showed consistent associations with urological complications. Anxiety may impair immunity, alter microbiota, or influence hormonal pathways, predisposing to UTIs [37–40]. Stress-related endocrine changes and behavioral risk factors may contribute to stone disease [41–43]. Heightened sympathetic activity and cortisol release can impair renal hemodynamics, increasing acute renal failure [44–49]. Chronic stress may also alter detrusor function and inflammatory responses, leading to hydronephrosis [50]. Conversely, anxiety appeared protective against cystitis, contrasting earlier studies; this discrepancy warrants further investigation [51, 52].

Depression alone showed no significant associations, but its coexistence with anxiety magnified risks, possibly due to synergistic effects on neuroendocrine pathways [13, 53–56].

This study has several limitations inherent to its retrospective design and use of the Nationwide Inpatient Sample (NIS). Diagnoses were identified using ICD-9 and ICD-10 codes, which may introduce misclassification or underreporting. The NIS lacks detailed clinical information and does not include variables specifying the neurological causes of neurogenic bladder, making it impossible to determine whether cases resulted from spinal cord injury, multiple sclerosis, Parkinson’s disease, or other disorders. In addition, the database only captures inpatient hospitalizations without data on outpatient management or long-term outcomes, which may underestimate the overall disease burden. Unmeasured factors such as disease severity, socioeconomic status, and treatment adherence may also contribute to residual confounding. Despite these limitations, the large, nationally representative nature of the NIS provides meaningful insights into the relationship between mental disorders and hospitalization outcomes in patients with neurogenic bladder.

Conclusion

Among hospitalized neurogenic bladder patients, depression, anxiety, and combined disorders were observed in 13.5%, 6.4%, and 5.1%, respectively, with higher rates among older adults and women. Anxiety was associated with increased risks of hydronephrosis, UTIs, stones, and acute renal failure, while paradoxically correlating with shorter hospitalizations and reduced mortality. Depression alone showed no clear association with complications, but depression-anxiety comorbidity amplified risks. These findings emphasize the complex role of mental health in neurogenic bladder outcomes and support the integration of psychiatric screening and multidisciplinary management to optimize care.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

Zheng and Xie were responsible for conceptualization and supervision. Data collection and analysis were performed by all authors. The first draft of the manuscript was written by Ni and Zhou. Liao, Zheng and Xie revised the manuscript. All authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Funding

This research received no external funding.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Conflict of interest

The authors declare no competing interests.

Human ethics and consent to participate declarations

Not applicable.