Impact of a COPD comprehensive case management program on hospital length of stay and readmission rates

Figures & data

Table 1 Admission rates for the COPD cohort during selected periods before and after program implementation (inpatients only)

Period	Total patients admitted	Patients admitted with primary dx COPD (%)	Total admissions	Admissions with primary dx COPD (%)
Preprogram	594	585 (98.5)	980	791 (80.7)
Program year 1	485	428 (88.2)	857	621 (72.5)
Program year 2	468	367 (78.4)	882	554 (62.8)

Abbreviation: dx, diagnosis.

Table 2 Admission rates for the COPD cohort during selected periods before and after program implementation (inpatients and ED visits)

Period	Total patients admitted/ED visit	Patients with primary dx COPD (%)	Total ED visits	ED visits with primary dx COPD (%)
Preprogram	597	586 (98.2)	333	69 (20.7)
Program year 1	527	450 (85.4)	562	126 (22.4)
Program year 2	542	404 (74.5)	882	203 (23)

Abbreviation: dx, diagnosis.

Figure 1 Distribution of numbers of readmissions (all causes and COPD only) within 90 days for patients with an index COPD admission prior to, or during years 1 and 2, of the program.

Table 3 Cox regression model statistics for all-cause readmissions

Effect	df	Chi-square	P-value
Gender	1	0.034	0.854
Facility	4	27.312	<0.001
Age	1	3.146	0.076
Program year	2	32.830	<0.001
Fiscal year	2	67.356	<0.001
Readmissions	6	1,088.647	<0.001
Resource intensity wt	1	14.765	<0.001

Abbreviation: wt, weight.

Figure 2 Mean cumulative number of all-cause readmissions relative to days since index COPD admission (inpatients only), based on Cox regression model.

Notes: Solid lines represent cohort means and colored bands represent 95% confidence intervals. Red = preprogram; green = program year 1; blue = program year 2.

Table 4 Cox regression model statistics for COPD related readmissions

Effect	df	Chi-square	P-value
Gender	1	0.072	0.789
Facility	4	9.316	0.054
Age	1	9.683	0.002
Program year	2	6.782	0.034
Fiscal year	2	19.942	<0.001
Readmissions	6	873.196	<0.001
Resource intensity wt	1	10.639	0.001

Abbreviation: wt, weight.

Figure 3 Mean cumulative number of readmissions with primary diagnosis of COPD relative to days since index COPD admission (inpatients only), based on Cox regression model.

Notes: Solid lines represent cohort means and colored bands represent 95% confidence intervals. Red = preprogram; green = program year 1; blue = program year 2.

Table 5 Regression model statistics for length of stay analysis among inpatients with primary diagnosis of COPD

Source	df	Chi-square	P-value
Age	1	14.85	<0.001
Gender	1	2.55	0.11
Facility	4	21.85	<0.001
Fiscal year	2	7.60	0.02
Resource intensity wt	1	34.68	<0.001
Program year	2	8.25	0.02
Gender × fiscal year	2	7.37	0.03
Resource intensity × gender	1	10.01	<0.001

Abbreviation: wt, weight.

Table S1 Parameter estimates from Cox regression model for all-cause readmissions

Parameter	Estimate	SE	Chi-square	P-value	Hazard ratio
Gender male	−0.011	0.061	0.034	0.854	0.989
Facility A	−0.092	0.077	1.436	0.231	0.912
Facility B	−0.250	0.094	7.009	0.008	0.779
Facility C	−0.171	0.078	4.788	0.029	0.843
Facility D	0.152	0.075	4.131	0.042	1.164
Age	−0.005	0.003	3.146	0.076	0.995
Program year 1	−0.602	0.105	32.809	<0.001	0.548
Program year 2	−0.683	0.154	19.571	<0.001	0.505
Fiscal year 2012/13	0.842	0.108	61.296	<0.001	2.321
Fiscal year 2013/14	1.095	0.148	54.791	<0.001	2.988
Readmissions =1	0.962	0.068	202.381	<0.001	2.617
Readmissions =2	1.451	0.090	258.780	<0.001	4.269
Readmissions =3	2.130	0.111	371.394	<0.001	8.417
Readmissions =4	2.088	0.131	254.700	<0.001	8.072
Readmissions =5	2.563	0.165	240.134	<0.001	12.976
Readmissions >5	3.177	0.136	542.089	<0.001	23.974
Resource intensity wt	−0.089	0.023	14.765	0.000	0.915

Notes: Estimates and hazard ratios relative to reference categories for gender (females), facilities (reference hospital), index COPD fiscal year (preprogram), fiscal year (2011/12), and number of readmissions (0).

Abbreviations: SE, standard error; wt, weight.

Table S2 Parameter estimates and hazard ratios from Cox regression model for MR Dx COPD readmissions

Parameter	Estimate	SE	Chi-square	P-value	Hazard ratio
Gender male	0.022	0.082	0.072	0.789	1.022
Facility A	−0.195	0.099	3.869	0.049	0.823
Facility B	−0.249	0.119	4.350	0.037	0.780
Facility C	−0.173	0.104	2.741	0.098	0.841
Facility D	−0.004	0.107	0.002	0.968	0.996
Age	−0.010	0.003	9.683	0.002	0.990
Program year 1	−0.301	0.116	6.766	0.009	0.740
Program year 2	−0.332	0.184	3.253	0.071	0.717
Fiscal year 2012/13	0.546	0.129	17.892	<0.001	1.727
Fiscal year 2013/14	0.721	0.187	14.808	<0.001	2.056
Readmissions =1	1.095	0.087	158.958	<0.001	2.989
Readmissions =2	1.809	0.121	222.215	<0.001	6.105
Readmissions =3	2.310	0.150	238.241	<0.001	10.079
Readmissions =4	2.299	0.192	143.789	<0.001	9.966
Readmissions =5	3.046	0.225	183.508	<0.001	21.026
Readmissions >5	3.671	0.248	218.270	<0.001	39.279
Resource intensity wt	−0.112	0.034	10.639	0.001	0.894

Notes: Estimates and hazard ratios relative to reference categories for gender (females), facilities (reference facility), index COPD fiscal year (preprogram), fiscal year (2011/12), and number of readmissions (0).

Abbreviations: SE, standard error; wt, weight; MR Dx COPD, primary diagnosis of COPD.

Table S3 Mean LOS in days among inpatients with primary diagnosis of COPD during selected periods before and after program implementation

Program	n	LOS (95% CI)
Preprogram	85	10.81a (7.31–14.31)
Program year 1	112	8.32a (6.67–9.97)
Program year 2	190	6.80b (5.56–8.03)

Notes: Letters indicate significant differences between program years at P<0.05;

a Program year 1 vs preprogram,

b Program year 2 vs preprogram.

Abbreviations: CI, confidence interval; LOS, length of stay.