TABLE 2

Patient Characteristics and Their Association With 30-Day Readmission

Patient Characteristic on Index VisitIndex Admission, n (%)All-Cause Readmission, n = 6346, 7.69%Pneumonia-Specific Readmission, a n = 2537, 3.07%
Unadjusted ORs for 30-d Readmission (95% CI)Adjusted ORs for 30-d Readmission (95% CI)Unadjusted ORs for 30-d Readmission (95% CI)Adjusted ORs for 30-d Readmission (95% CI)
Age
 0–30 d422 (0.51)1.24 (0.87–1.77)1.96 (1.33–2.87)**1.06 (0.60–1.89)1.48 (0.62–3.52)
 31–365 d12 509 (15.15)1.64 (1.53–1.76)**1.73 (1.63–1.83)**1.25 (1.11–1.40)**1.36 (1.14–1.61)**
 1–4 y37 391 (45.29)RefRefRefRef
 5–12 y23 948 (29.00)0.99 (0.92–1.05)0.87 (0.82–0.93)**1.12 (1.02–1.24) * 1.02 (0.92–1.13)
 13–18 y6893 (8.35)1.74 (1.59–1.89)**1.01 (0.91–1.11)1.69 (1.48–1.92)**1.18 (1.00–1.39)
 >18 y1403 (1.70)2.94 (2.55–3.40)**0.97 (0.82–1.15)2.28 (1.81–2.88)**1.06 (0.82–1.36)
Girls38 220 (46.29)0.91 (0.86–0.96) * 0.96 (0.91–1.02)0.92 (0.85–1.00)0.94 (0.85–1.04)
Race/Ethnicity
 Non-Hispanic white34 769 (45.66)RefRefRefRef
 Non-Hispanic black18 563 (24.38)0.93 (0.87–0.99) * 1.02 (0.92–1.12)0.90 (0.81–1.00)1.00 (0.85–1.18)
 Hispanic19 753 (25.94)1.03 (0.96–1.09)1.05 (0.98–1.14)0.99 (0.89–1.09)1.05 (0.94–1.16)
 Asian2287 (3.00)0.77 (0.64–0.91) * 0.90 (0.73–1.12)0.85 (0.65–1.10)0.97 (0.74–1.29)
 Other775 (1.02)0.98 (0.75–1.29)1.16 (0.86–1.57)1.10 (0.74–1.62)1.25 (0.89–1.75)
Government payer47 632 (57.69)1.22 (1.16–1.29) * 0.95 (0.89–1.02)1.03 (0.95–1.12)0.88 (0.76–1.02)
Proximity to hospital, miles
 <2055 501 (69.10)RefRefRefRef
 ≥2024 819 (30.90)1.21 (1.15–1.28) * 1.02 (0.95–1.09)1.07 (0.98–1.17)0.94 (0.84–1.06)
Median household income b
 ≤1.5×FPL22 317 (27.68)RefRefRefRef
 1.5–2×FPL24 799 (30.76)0.99 (0.92–1.06)0.97 (0.89–1.05)0.93 (0.84–1.04)0.89 (0.79–1.00)
 2–3×FPL24 840 (30.81)0.93 (0.87–1.00)0.99 (0.91–1.07)0.99 (0.89–1.10)1.00 (0.88–1.13)
 >3×FPL8675 (10.76)0.93 (0.85–1.02)1.03 (0.92–1.15)0.97 (0.84–1.12)0.95 (0.79–1.14)
CCI present c 49 962 (60.51)3.01 (2.82–3.21)**1.84 (1.69–2.01)**
No. of CCIs
 032 604 (39.49)RefRefRefRef
 126 376 (31.95)1.42 (1.31–1.53)**1.58 (1.42–1.75)**1.09 (0.97–1.21)1.19 (1.01–1.39) *
 29595 (11.62)3.38 (3.10–3.68)**2.41 (2.14–2.72)**1.94 (1.71–2.21)**1.52 (1.27–1.82)**
 35697 (6.90)5.10 (4.65–5.58)**2.86 (2.52–3.25)**2.87 (2.50–3.28)**1.88 (1.58–2.25)**
 4 or more8294 (10.05)7.10 (6.57–7.68)**3.38 (2.93–3.89)**3.54 (3.16–3.97)**1.97 (1.60–2.42)**
Asthma25 159 (30.47)0.71 (0.67–0.76)**0.62 (0.57–0.68)**0.78 (0.71–0.86)**0.74 (0.64–0.85)**
Technology dependence11 737 (14.22)4.22 (4.00–4.46)**1.07 (0.98–1.16)2.85 (2.61–3.11)**1.15 (1.03–1.29) *
No. hospitalizations in previous y
 059 179 (71.67)RefRefRefRef
 19131 (11.06)2.83 (2.62–3.06)**1.92 (1.76–2.09)**1.83 (1.62–2.07)**1.48 (1.32–1.67)**
 25845 (7.08)3.46 (3.17–3.77)**2.31 (2.10–2.54)**2.09 (1.82–2.40)**1.47 (1.24–1.74)**
 3+8411 (10.19)8.56 (8.04–9.12)**4.60 (4.22–5.01)**4.55 (4.14–5.00)**2.70 (2.35–3.10)**
Pneumonia-specific hospitalization in previous y6243 (7.56)3.11 (2.90–3.34)**0.95 (0.86–1.03)2.98 (2.69–3.31)**1.37 (1.17–1.61)**
Hospital LOS, d
 1–2 44 215 (53.55)RefRefRefRef
 3–7 28 882 (34.98)1.72 (1.63–1.83)**1.13 (1.05–1.22)**1.47 (1.35–1.61)**1.05 (0.96–1.16)
 >7 9469 (11.47)3.36 (3.13–3.60)**1.39 (1.23–1.56)**2.08 (1.86–2.32)**0.97 (0.85–1.11)
ICU care received9509 (11.52)2.20 (2.06–2.35)**1.10 (1.00–1.21)1.66 (1.49–1.84)**1.07 (0.96–1.20)
Complicated pneumonia
 None (uncomplicated)73 247 (88.71)RefRefRefRef
 Complicated pneumonia diagnosis alone d 6457 (7.82)1.08 (0.99–1.19)1.32 (1.11,1.56)**1.62 (1.43–1.83)**1.82 (1.44–2.31)**
 Complicated pneumonia with pleural drainage procedure e 2862 (3.47)0.91 (0.79–1.05)0.99 (0.82–1.20)1.11 (0.90–1.38)1.19 (0.89–1.59)
  • * P < .05. ** P < .01. —, CCI as a binary variable (present vs absent) was not considered as a candidate predictor in the multivariable model, as it was used in the model as an ordinal variable (No. of CCI's).

  • a Readmission within 30 days of discharge from index hospitalization with diagnosis of pneumonia in any diagnosis field (ICD-9 codes 481–483.8, 485–486).

  • b Median household income based on zip code of residence.

  • c CCIs developed by the Agency for Healthcare Research and Quality categorize more than 14 000 ICD-9 codes into chronic versus nonchronic conditions.

  • d Complicated pneumonia defined by the presence of empyema (510.0 and 510.9), pleurisy (511.0 and 511.1), pleural effusion (511.9), and abscess of lung (513.0).

  • e Pleural drainage procedure defined by ICD-9 codes for thoracentesis (34.91), chest tube placement (34.04), video-assisted thoracoscopic surgery (34.21), and thoracotomy (34.02 and 34.09).