Article

Analysis of Incidence and Outcome Predictors for Patients Admitted to US Hospitals with Acetabular Fractures from 1990 to 2010

Publish date: September 27, 2018

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MORTALITY

In-hospital mortality decreased from 5.9% in 1990 to 0.4% in 2010 (P < .001) (3.5% for the total cohort) (Tables 1 and 2). Multivariable logistic regression analysis demonstrated pulmonary insufficiency (odds ratio [OR], 9.07; 95% confidence interval [CI], 8.52-9.66; P < .01), pneumonia (OR, 3.22; 95% CI, 3.05-3.39; P < .01), and age >85 years (OR, 2.28; 95% CI, 2.16-2.40; P < .01) to be associated with the highest odds of inpatient mortality. CRIF (OR, 1.99; 95% CI, 1.78-2.23; P < .01), external fixator (OR, 1.82; 95% CI, 1.45-2.29; P < .01), and having received a blood transfusion (OR, 1.81; 95% CI, 1.71-1.91; P < .01) were also associated with increased odds of mortality. Treatment with ORIF (OR, 0.19; 95% CI, 0.17-0.20; P < .01) was independently associated with decreased odds of inpatient mortality, as was age <20 years (OR, 0.26; 95% CI, 0.23-0.30; P < .01) (model fit: for omnibus test of model coefficients, X = 25,966 P < .01; Nagelkerke, R² = 0.20) (Table 3).

Table 3. Logistic Regression for Predictors of Mortality Among Patients with Acetabular Fractures (n = 403,927)

Variable	OR (95% CI)	P
Pulmonary insufficiency	9.07 (8.52–9.66)	< 0.01
Pneumonia	3.22 (3.05–3.39)	< 0.01
Age >85 years	2.28 (2.16–2.40)	< 0.01
Closed reduction internal fixation	1.99 (1.78–2.23)	< 0.01
External Fixator	1.82 (1.45–2.29)	< 0.01
Blood transfusion	1.81 (1.71–1.91)	< 0.01
Gender (male)	1.76 (1.70–1.83)	< 0.01
Associated femoral neck fracture	1.23 (1.15–1.30)	< 0.01
Age 41-60 years	1.19 (1.11–1.29)	< 0.01
Age 61-85 years	1.17 (1.11–1.23)	< 0.01
Congestive heart failure	1.14 (1.07–1.22)	< 0.01
Associated pelvic fracture	1.13 (1.10–1.17)	< 0.01
Geographic region	1.11 (1.09–1.12)	< 0.01
Source of payment	1.02 (1.01–1.02)	< 0.01
Race	0.99 (0.98–0.99)	< 0.01
DOC	0.98 (0.98–0.98)	< 0.01
Hypertension	0.67 (0.64–0.71)	< 0.01
Atrial fibrillation	0.52 (0.48–0.57)	< 0.01
Diabetes mellitus	0.35 (0.32–0.38)	< 0.01
Age 20-40 years	0.32 (0.30–0.35)	< 0.01
Age <20 years	0.26 (0.23–0.30)	< 0.01
Coronary artery disease	0.21 (0.18–0.24)	< 0.01
Open reduction internal fixation	0.19 (0.17–0.20)	< 0.01
Omnibus X 25,966, P < .01
Nagelkerke R²= 0.20

Abbreviations: CI, confidence interval; DOC, days of care; OR, odds ratio.

COMORBIDITIES AND ADVERSE EVENTS

The prevalence of comorbidities and adverse events is listed in Tables 4 and 5, respectively. Hypertensive disease was the most common comorbidity at 15.3%, followed by diabetes mellitus at 6.9%. Overall, 25.9% of patients experienced an in-hospital adverse event, with the most common being postoperative anemia (7.3%) and blood transfusion (8.1%) (Tables 1 and 5). The percentage of patients experiencing an adverse event increased from 10.9% in 1990 to 37.6% in 2010 (P < .01) (Table 2). Multivariable logistic regression analysis revealed CRIF (OR, 3.08; 95% CI, 2.91-3.26; P < .01), coronary artery disease (OR, 2.02; 95% CI, 1.91-2.15; P < .01), associated femoral neck fracture (OR, 1.53; 95% CI, 1.47-1.60; P < .01), and ORIF (OR, 1.22; 95% CI, 1.20-1.24; P < .01) to be associated with higher odds of inpatient adverse events (model fit: for omnibus test of model coefficients, X = 160,275, P < .01; Nagelkerke, R² = 0.41) (Table 6).

Table 4. Prevalence of Comorbidities in Patients with Acetabular Fractures Between 1990 and 2007 (n = 403.927)

*Parameter (ICD-9)*	Percentage of Total
Hypertensive disease (401–405)	15.3%
Diabetes mellitus (250)	6.9%
Atrial fibrillation (427.31)	4.0%
Congestive heart failure (428)	3.9%
Osteoporosis (733.0)	2.1%
Coronary artery disease (414.01)	2.0%
Obesity (278.00, 278.01)	2.0%

Abbreviation: ICD-9, International Classifications of Diseases, 9th Revision.

Table 5. Prevalence of In-Hospital Adverse Events Among Patients with Acetabular Fractures Between 1990 and 2007 (n = 403,927)

*Parameter (ICD-9)*	Percentage of Total
Transfusion of blood (99.0)	8.1%
Acute postoperative anemia (285.1)	7.3%
Intubation (96.x)	4.9%
Acute renal failure (584)	3.4%
Pneumonia (480-486)	3.2%
Pulmonary insufficiency (518.5)	2.3%
Pulmonary embolism (415.1)	1.6%
Deep venous thrombosis (453.4)	1.0%
Acute myocardial infarction (410)	0.9%
Postoperative bleeding (998.1)	0.7%
Acute postoperative infection (998.5)	0.5%
Induced mental disorder (293)	0.4%

Abbreviation: ICD-9, International Classifications of Diseases, 9th Revision.

Table 6. Logistic Regression for Predictors of Adverse Events Among Patients Hospitalized for Acetabular Fracture (n = 403,927)

Variable	OR (95% CI)	P
Closed reduction internal fixation	3.08 (2.91-3.26)	< 0.01
Coronary artery disease	2.02 (1.91-2.15)	< 0.01
Associated femoral neck fracture	1.53 (1.47-1.60)	< 0.01
Open reduction internal fixation	1.22 (1.20-1.24)	< 0.01
Gender (male)	1.16 (1.14-1.18)	< 0.01
Associated fracture of any part of femur	1.13 (1.10-1.17)	< 0.01
Age >85 years	1.08 (1.05-1.12)	< 0.01
Geographic region	1.07 (1.06-1.07)	< 0.01
DOC	1.04 (1.04-1.04)	< 0.01
Race	1.02 (1.02-1.03)	< 0.01
Source of payment	1.01 (1.01-1.01)	< 0.01
Congestive heart failure	1.01 (0.96-1.06)	0.78
Atrial fibrillation	0.88 (0.84-0.92)	< 0.01
Age 61-85 years	0.68 (0.66-0.71)	< 0.01
Age <20 years	0.67 (0.64-0.70)	< 0.01
Associated pelvis fracture	0.64 (0.63-0.66)	< 0.01
Age 41-60 years	0.58 (0.56-0.61)	< 0.01
Diabetes mellitus	0.48 (0.46-0.50)	< 0.01
Age 20-40 years	0.45 (0.43-0.47)	< 0.01
Hypertension	0.44 (0.43-0.45)	< 0.01
External Fixator	0.39 (0.35-0.44)	< 0.01
Omnibus X 160,275, P < .01
Nagelkerke R² = 0.41

Abbreviations: CI, confidence interval; DOC, days of care; OR, odds ratio.

BLOOD TRANSFUSION

Overall, 7.3% of patients experienced acute postoperative anemia (Table 5). Between 1990 and 2010, the percentage of patients receiving blood transfusions increased from 0.3% to 9.5%, respectively (P < .01) (Table 2). In multivariable logistic regression analysis, patients treated with ORIF (OR, 8.13; 95% CI, 7.91-8.36; P < .01), those with congestive heart failure (OR, 4.23; 95% CI, 4.06-4.41; P < .01), those with an associated femur fracture (OR, 3.13; 95% CI, 2.99-3.27; P < .01), those with atrial fibrillation (OR, 1.96; 95% CI, 1.88-2.05; P < .01), and those treated with CRIF (OR, 1.42; 95% CI, 1.29-1.56; P < .01) were associated with significantly higher odds of blood transfusion (model fit: omnibus test of model coefficients, X = 42,653, P < .01; Nagelkerke, R² = 0.19) (Table 7).

Table 7. Logistic Regression for Predictors of the Requirement for Blood Transfusion Among Patients with Acetabular Fractures (n = 403,927)

Variable	OR (95% CI)	P
Open reduction internal fixation	8.13 (7.91-8.36)	< 0.01
Congestive heart failure	4.23 (4.06-4.41)	< 0.01
Associated fracture of any part of femur	3.13 (2.99-3.27)	< 0.01
Atrial fibrillation	1.96 (1.88-2.05)	< 0.01
Closed reduction internal fixation	1.42 (1.29-1.56)	< 0.01
Geographic region	1.38 (1.36-1.39)	< 0.01
Hypertension	1.38 (1.34-1.42)	< 0.01
Associated pelvic fracture	1.28 (1.25-1.31)	< 0.01
Age 61-85 years	1.06 (1.02-1.11)	0.01
Source of payment	0.99 (0.98-0.99)	< 0.01
Race	0.98 (0.97-0.98)	< 0.01
DOC	0.96 (0.96-0.96)	< 0.01
Age >85 years	0.74 (0.72-0.77)	< 0.01
External fixator	0.69 (0.59-0.80)	< 0.01
Coronary artery disease	0.62 (0.57-0.68)	< 0.01
Age 41-60 years	0.57 (0.54-0.60)	< 0.01
Gender (male)	0.54 (0.52-0.55)	< 0.01
Diabetes mellitus	0.38 (0.36-0.41)	< 0.01
Age 20-40 years	0.32 (0.30-0.34)	< 0.01
Associated femoral neck fracture	0.29 (0.27-0.31)	< 0.01
Age <20 years	0.24 (0.22-0.26)	< 0.01
Omnibus X = 42,653, P < .01
Nagelkerke R²= 0.19

Abbreviations: CI, confidence interval; DOC, days of care; OR, odds ratio.

TREATMENT WITH ORIF

Over the 20-year study period, 23.2% of patients with acetabular fractures were treated with ORIF (Table 1). In 1990, 12.6% of patients underwent ORIF, while in 2010 this percentage increased to 20.4% (P < .001) (Table 2). Multivariable logistic regression analysis demonstrated that age between 41 and 60 years (OR, 1.88; 95% CI, 1.78-1.98; P < .01) was associated with the highest odds of undergoing ORIF. Age 20 to 40 years (OR, 1.86; 95% CI, 1.76-1.97; P < .01), age <20 years (OR, 1.82; 95% CI, 1.72-1.93; P < .01), and male gender (OR, 1.65; 95% CI, 1.63-1.68; P < .01) were also associated with being treated by ORIF. In contrast, coronary artery disease (OR, 0.27; 95% CI, 0.25-0.30; P < .01), age >85 years (OR, 0.46; 95% CI, 0.44-0.47; P < .01), and congestive heart failure (OR, 0.48; 95% CI, 0.46-0.51; P < .01) were associated with the lowest odds of undergoing ORIF (model fit: omnibus test of model coefficients, X = 71,118, P < .01; Nagelkerke, R² = 0.20) (Table 8).

Table 8. Logistic Regression for Predictors of the Requirement for Discharge to Another Inpatient Facility Among Patients with Acetabular Fractures (n = 403,927)

Variable	OR (95% CI)	P
Age 41-60 years	1.88 (1.78-1.98)	< 0.01
Age 20-40 years	1.86 (1.76-1.97)	< 0.01
Age <20 years	1.82 (1.72-1.93)	< 0.01
Gender (male)	1.65 (1.63-1.68)	< 0.01
Larger hospital bed size	1.46 (1.45-1.47)	< 0.01
Hypertension	1.35 (1.32-1.38)	< 0.01
Diabetes mellitus	1.09 (1.05-1.13)	< 0.01
DOC	1.02 (1.02-1.02)	< 0.01
Source of payment	1.01 (1.01-1.02)	< 0.01
Race	1.00 (0.99-1.00)	0.17
Age 61-85 years	0.94 (0.90-0.99)	0.02
Region	0.92 (0.91-0.93)	< 0.01
Atrial fibrillation	0.83 (0.79-0.87)	< 0.01
Congestive heart failure	0.48 (0.46-0.51)	< 0.01
Age >85 years	0.46 (0.44-0.47)	< 0.01
Coronary artery disease	0.27 (0.25-0.30)	< 0.01
Omnibus X 71,118, P < .01
Nagelkerke R²= 0.20

Abbreviations: CI, confidence interval; DOC, days of care; OR, odds ratio.

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