TABLE 2.

Characteristics of Hospitals Included in Aggregated Cohort

	Cohort Proportion	Non-COPD		COPD
		Rate	P	Rate	P
Hospital ownership/control, %			<.001		.965
Government, non-federal	16.1%	9.1%		7.7%
Private, non-profit	62.9%	9.6%		7.7%
Private, for-profit	21.0%	9.8%		7.7%
Hospital teaching status, %			<.001		<.001
Metro, non-teaching	44.2%	9.8%		7.6%
Metro, teaching	30.0%	9.7%		7.9%
Non-metro, non-teaching	25.8%	8.7%		7.3%
Hospital geographic location, %			<.001		<.001
Large metro area ≥1M	43.7%	10.1%		7.9%
Small metro area <1M	30.5%	9.3%		7.5%
Micropolitan area	15.3%	8.8%		7.3%
Non-metro/non-micropolitan (rural)	10.5%	8.3%		7.3%
Hospital bed size, %			<.001		<.001
Small	26.6%	9.1%		7.5%
Medium	32.3%	9.5%		7.7%
Large	41.1%	9.7%		7.7%
Hospital total all-cause annual discharges, Mean ± SD	6,296 ± 6,425
Quartiles of Hospital total all-cause annual discharges, %			<.001		<.001
1st Quartile (≤8,971)	59.2%	8.3%		7.2%
2nd Quartile (8,972-15,406)	20.8%	9.3%		7.5%
3rd Quartile (15,407-24,534)	13.0%	9.7%		7.7%
4th Quartile (≥24,535)	7.1%	9.9%		7.9%
COPD Discharges, Mean ± SD	161 ± 133
COPD Discharge Quartiles			<.001		<.001
1st Quartile (≤ 122)	48.5%	8.8%		7.0%
2nd Quartile (123-205)	24.0%	9.5%		7.5%
3rd Quartile (206-322)	17.1%	9.7%		7.9%
4th Quartile (≥ 323)	10.3%	10.0%		8.1%
Proportion Medicaid patient days, Mean ± SD	17.1% ± 11.2%
Medicaid Proportion Quartiles, %			0.451		<.001
1st Quartile (≤ 10.6%)	31.5%	9.6%		7.2%
2nd Quartile (10.6% - 16.1%)	25.4%	9.6%		7.7%
3rd Quartile (16.1% - 23.9%)	22.8%	9.5%		7.8%
4th Quartile (≥ 23.9%)	20.4%	9.5%		8.2%

Note: Unweighted frequencies displayed for cohort proportions.

Weighted frequencies for sub-strata readmission rates presented.

P values are for between hospital characteristic differences in readmission rates.

Abbreviations: COPD, chronic obstructive pulmonary disease