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Table 2 Patient Cohort Demographics

From: A machine learning model to predict the risk of 30-day readmissions in patients with heart failure: a retrospective analysis of electronic medical records data

Patient Characteristics

Whole Cohort

Patients with readmissions

Patients without readmissions

p-value

N = 11,510

n = 3502

n = 8008

Age Distribution

   

0.75

 Median (1, 3 quartile)

75.7 (64.3, 84.7)

76.0 (64.4, 84.6)

75.5 (64.2, 84.7)

 

Gender, n (%)

   

0.74

 Male

6073 (52.8)

1839 (52.5)

4234 (52.9)

 

Race, n (%)

   

0.16

 White

9490 (84.5)

2872 (83.8)

6618 (84.9)

 

 Black or African American

889 (7.9)

297 (8.7)

592 (7.6)

 

 Hispanic or Latino (all races)

423 (3.8)

141 (4.1)

282 (3.6)

 

 Asian

221 (2.0)

61 (1.8)

160 (2.1)

 

 Other, or more than one race

202 (1.8)

58 (1.7)

144 (1.8)

 

 Unknown (excluded in calculations)

n = 285

n = 73

n = 212

 

Marital status, n (%)

   

0.07

 Married / Partnered

5125 (45.6)

1516 (44.3)

3609 (46.2)

 

 Widow

2360 (21.0)

718 (21)

1642 (21)

 

 Single

2274 (20.2)

715 (20.9)

1559 (19.9)

 

 Divorced / Separated

1069 (9.5)

323 (9.4)

746 (9.5)

 

 Other

412 (3.7)

148 (4.3)

264 (3.4)

 

 Unknown (excluded in calculations)

n = 270

n = 82

n = 188

 

Highest educational attainment, n (%)

   

< 0.01*

 Some High School or Less

1117 (12.7)

392 (14.2)

725 (12)

 

 High School Graduate/GED

3418 (38.7)

1127 (40.7)

2291 (37.8)

 

 Some College/Vocational/Technical Program

492 (5.6)

134 (4.8)

358 (5.9)

 

 Graduate of College or Postgraduate School

2911 (33.0)

864 (31.2)

2047 (33.8)

 

 Other

887 (10.1)

253 (9.1)

634 (10.5)

 

 Unknown (excluded in calculations)

n = 2685

n = 732

n = 1953

 

Employment status, n (%)

   

< 0.01*

 Retired

4338 (57.3)

1329 (57.7)

3009 (57.1)

 

 Employed a

2067 (27.3)

556 (24.1)

1511 (28.7)

 

 Disability

656 (8.7)

259 (11.2)

397 (7.5)

 

 Unemployed

467 (6.2)

149 (6.5)

318 (6)

 

 Other

49 (0.6)

12 (0.5)

37 (0.7)

 

 Unknown (excluded in calculations)

n = 3933

n = 1197

n = 2736

 

Number of comorbidities, n (%) b

   

< 0.01*

 0

2619 (22.8)

578 (16.5)

2041 (25.5)

 

 1

3032 (26.3)

840 (24)

2192 (27.4)

 

 2

2684 (23.3)

841 (24)

1843 (23)

 

  ≥ 3

3175 (27.6)

1243 (35.5)

1932 (24.1)

 
  1. aIncludes part-time and self-employment
  2. bThe following list of comorbidities was selected based on a literature review of comorbidities frequently found in patients with heart failure [27,28,29,30,31,32,33], in addition to clinical opinion of study staff physicians. Please see Additional file 3: Appendix B for a complete list of ICD-9 codes used to identify each condition. Each condition evaluated is listed here with the percentage of the study population who presented to a PHS facility with the condition as the principal diagnosis for either an inpatient or outpatient encounter at least once between 2014 and 2015. Hypertension (37.3%), cardiovascular disease (32.5%), chronic kidney disease / renal insufficiency (26.1%), non-secondary diabetes mellitus (22.8%), anemia (19.2%), chronic obstructive pulmonary disease (9.8%), osteoarthritis (9.1%), mental health conditions (7.2%), back pain (3.3%), osteoporosis (3.2%), obesity (2.3%)