Table 4 Predictors of duration of hospital stay among patients with COPD who were admitted to the hospital after presenting to ED with COPD as the primary diagnosis using linear regression

Age

  < 50

Ref

Ref

 50- <65

0.52 (0.43,0.61)

<0.0001

0.50 (0.40, 0.59)

<0.0001

 65- <80

1.00 (0.89,1.10)

<0.0001

0.82 (0.70, 0.93)

<0.0001

  ≥ 80

1.18 (1.06,1.31)

<0.0001

0.85 (0.73, 0.98)

<0.0001

Gender

 Female

Ref

Ref

 Male

-0.28 (-0.34, -0.23)

<0.0001

-0.29 (-0.34, -0.24)

<0.0001

Median house hold income

 1st quartile (< $38,999)

Ref

Ref

 2nd quartile ($39,000 to $47,999)

0.00 (-0.10, 0.10)

0.9732

-0.03 (-0.12, 0.07)

0.5973

 3rd quartile ($48,000 to $62999)

0.05 (-0.06, 0.15)

0.3623

-0.07 (-0.17, 0.03)

0.1951

 4th quartile ($63,000 or more)

0.40 (0.20, 0.59)

0.0001

0.11 (-0.05, 0.28)

0.1895

Primary payer

 Medicare (ref)

Ref

Ref

 Medicaid

-0.42 (-0.52, -0.32)

<0.0001

-0.06 (-0.16, 0.04)

0.2685

 Private insurance

-0.52 (-0.61, -0.43)

<0.0001

-0.26 (-0.34, -0.17)

<0.0001

 Self-pay/no charge

-1.19 (-1.29, -1.09)

<0.0001

-0.74 (-0.85, -0.64)

<0.0001

 Other

-0.61 (-0.80, -0.42)

<0.0001

-0.26 (-0.42, -0.10)

0.0013

Patient location (residence)

 Micropolitan/not metro

Ref

Ref

 Metro (large or small)

0.35 (0.23, 0.47)

<0.0001

0.28 (0.15, 0.41)

<0.0001

Hospital Region

 Northeast

Ref

Ref

 Midwest

-0.79 (-1.02, -0.57)

<0.0001

-0.67 (-0.89, -0.45)

<0.0001

 South

-0.43 (-0.65, -0.21)

0.0001

-0.27 (-0.48, -0.07)

0.0103

 West

-0.80 (-1.03, -0.58)

<0.0001

-0.76 (-0.98, -0.54)

<0.0001

Teaching status of hospital

 Metropolitan non-teaching or non-metropolitan

Ref

Ref

 Metropolitan teaching

0.15 (0.01, 0.30)

0.0363

0.03 (-0.12, 0.18)

0.7276

Comorbidities

 CHD (ref: no)

0.16 (0.10, 0.21)

<0.0001

-0.03 (-0.09, 0.02)

0.2051

 Hyperlipidemia (ref: no)

-0.20 (-0.25, -0.14)

<0.0001

-0.30 (-0.35, -0.25)

<0.0001

 Renal failure (ref: no)

0.51 (0.43, 0.58)

<0.0001

0.26 (0.19, 0.33)

<0.0001

 CHF (ref: no)

0.84 (0.78, 0.90)

<0.0001

0.73 (0.66, 0.79)

<0.0001

 Gout (ref: no)

-0.02 (-0.17, 0.13)

0.8001

-0.24 (-0.39, -0.08)

0.0029

 Diabetes (ref: no)

0.12 (0.06, 0.17)

<0.0001

0.03 (-0.02, 0.08)

0.2479

 Hypertension (ref: no)

-0.00 (-0.06, 0.05)

0.9132

-0.15 (-0.21, -0.09)

<0.0001

 Osteoarthritis (ref: no)

-0.01 (-0.10,0.09)

0.8771

-0.07 (-0.16, 0.03)

0.1554