Health care utilization history, GOLD guidelines, and respiratory medication prescriptions in patients with COPD

Figures & data

Figure 1 Flow diagram for inclusion and exclusion of study patients.

Note: The diagnosis of COPD was defined by ICD-9 codes, 491.XX (Chronic Bronchitis), 492.XX (Emphysema) and 496.XX (Chronic Obstructive Lung Disease).

Table 1 Characteristics of the 523 study subjects

Gender
Male	498 (95%)
Female	25 (5%)
Age (years)	66.5 ± 11.0
Race
White	444 (85%)
African-American	68 (13%)
Asian	1 (0.2%)
Other/not noted	10 (2%)
Spirometry
within 2 years	321 (61%)
within 5 years	523 (100%)
Smoking status
current smoker	257 (50%)
former smoker	245 (47%)
never smoker	17 (3%)
Medications
Short acting beta agonist	346 (66%)
Long acting beta agonist	114 (22%)
Ipratroprium	181 (35%)
Albuteral/Ipratroprium (Combivent^®)	114 (22%)
Theophylline	46 (9%)
Tiotroprium	10 (2%)
Inhaled steroid	158 (30%)
Systemic steroid	31 (6%)
Supplemental oxygen	121 (23%)

Notes: Age is mean ± SD; all others are n (%).

Table 2 Distribution of patients, FEV₁, and FEV₁/FVC according to modified GOLD stage

Modified GOLD stage	n (%)	FEV1 (I)	FEV1/FVC (%)
Clinical	131 (25%)	2.47 ± 0.71 (2.35 – 2.59)	77.2 ± 5.69 (76.27 – 78.22)
COPD
1	28 (5%)	2.66 ± 0.61 (2.44 – 2.88)	65.1 ± 3.17 (63.89 – 66.25)
2	134 (25.6%)	2.03 ± 0.50 (1.94 – 2.11)	58.8 ± 6.57 (57.63 – 59.86)
3	113 (21.6%)	1.29 ± 0.32 (1.23 – 1.35)	47.9 ± 8.92 (46.2 – 49.49)
4	117 (22.4%)	0.89 ± 0.28 (0.84 – .94)	42.3 ± 9.31 (40.63 – 44)

Notes: Results are mean ± SEM (95% confidence intervals).

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.

Figure 2 Distribution of health care encounters over 12 and 60 month intervals.

Notes: Results are mean ± SEM. Panel A shows hospital, ED, outpatient, and total respiratory visits. Panel B shows hospital, ED, outpatient, and total nonrespiratory visits.

Abbreviations: Hospital, hospitalizations; ED, emergency department visits; Outpatient, outpatient health care encounters; All, total health care encounters.

Figure 3 Health care encounters during the 12 month period (A, B) and the 60 month period (C, D) according to modified GOLD stage.

Notes: Results are mean ± SEM (95% confidence interval). Panel A shows hospital, ED, outpatient, and total respiratory visits. Patients with advanced COPD had more respiratory health care visits compared with individuals with a clinical diagnosis of COPD (0.36 ± 0.067 (0.24, 0.54), 0.29 ± 0.15 (0.11, 0.77), 0.58 ± 0.11 (0.42, 0.80), 1.0 ± 0.23 (0.77, 1.3), and 1.4 ± 0.19 (1.1, 1.7) visits/person/year over the 12 month period for clinical COPD (former GOLD stage 0) and modified GOLD stages 1, 2, 3, and 4 respectively, 4 df ANOVA P < 0.001). Panel B shows hospital, ED, outpatient, and total nonrespiratory visits. The frequency of nonrespiratory health care visits was the same in all groups regardless of modified GOLD stage (3.8 ± 0.24 (3.4, 4.3), 3.2 ± 0.39 (2.4, 4.3), 3.3 ± 0.24 (2.9, 3.8), 3.6 ± 0.46 (3.1, 4.1), and 3.8 ± 0.31 (3.3, 4.3) visits/person/year for clinical COPD and modified GOLD stages 1, 2, 3, and 4 respectively, 4 df ANOVA P = 0.51). Panel C shows the number of office, ED, and hospital respiratory visits increasing with each modified GOLD stage from 0.34 ± 0.032 visits/person/year in patients with a clinical diagnosis of COPD to 1.1 ± 0.13 visits/person/year for those individuals in modified GOLD stage 4 (4df ANOVA comparing all groups, P < 0.001). Panel D shows similar numbers of hospital, ED, office, and total nonrespiratory visits in each modified GOLD stage, 4df ANOVA comparing all groups P = 0.45).

Figure 4 Frequency of yearly health care respiratory health care encounters per person during the 12 and 60 month periods.

Table 3 Respiratory and nonrespiratory health care encounters over the 12 and 60 month periods based upon modified GOLD stage and prescription level

Health care encounters		Clinical COPD			Modified GOLD 1 + 2				Modified GOLD 3 + 4
		Prescriptions per guidelines	More prescriptions than guidelines	P value*	Less prescriptions than guidelines	Prescriptions per guidelines	More prescriptions than guidelines	P value**	Less prescriptions than guidelines	Prescriptions per guidelines	P value*
		(=G)	(>G)		(<G)	(=G)	(>G)		(<G)	(=G)
Respiratory Visits in 12 months visits/person/year	Hospital	0.032 ± 0.018 (0.016, 0.061)	0.14 ± 0.071 (0.084, 0.23)	0.0002	0.018 ± 0.013 (0.0074, 0.045)	0.19 ± 0.19 (0.089, 0.39)	0.27 ± 0.011 (0.18, 0.41)	<0.001	0.19 ± 0.04 (0.13, 0.26)	0.56 ± 0.16 (0.4, 0.79)	<0.0001
	ED	0.053 ± 0.023 (0.029, 0.097)	0.22 ± 0.11 (0.11, 0.36)	0.0004	0.15 ± 0.047 (0.093, 0.23)	0.31 ± 0.25 (0.14, 0.71)	0.43 ± 0.12 (0.27, 0.68)	0.0047	0.3 ± 0.058 (0.22, 0.41)	1 ± 0.2 (0.76, 1.4)	<0.0001
	Outpatient	0.19 ± 0.05 (0.13, 0.28)	0.22 ± 0.09 (0.12, 0.41)	0.67	0.15 ± 0.041 (0.094, 0.23)	0.25 ± 0.11 (0.1, 0.61)	0.38 ± 0.17 (0.24, 0.61)	0.02	0.3 ± 0.049 (0.22, 0.4)	0.83 ± 0.19 (0.61, 1.1)	<0.0001
	All	0.27 ± 0.057 (0.18, 0.41)	0.58 ± 0.19 (0.37, 0.91)	0.016	0.31 ± 0.073 (0.21, 0.47)	0.75 ± 0.5 (0.37, 1.5)	1.1 ± 0.27 (0.74, 1.6)	<0.0001	0.78 ± 0.11 (0.6, 1)	2.4 ± 0.47 (1.9, 3.1)	<0.0001
Respiratory Visits in 60 months visits/person/year	Hospital	0.025 ± 0.0091 (0.016, 0.041)	0.056 ± 0.02 (0.033, 0.094)	0.001	0.022 ± 0.0075 (0.013, 0.037)	0.063 ± 0.04 (0.028, 0.14)	0.13 ± 0.037 (0.09, 0.19)	<0.0001	0.14 ± 0.025 (0.11, 0.19)	0.25 ± 0.061 (0.18, 0.36)	0.016
	ED	0.061 ± 0.014 (0.04, 0.093)	0.17 ± 0.055 (0.11, 0.25)	0.034	0.088 ± 0.018 (0.059, 0.13)	0.16 ± 0.069 (0.076, 0.35)	0.35 ± 0.093 (0.25, 0.49)	<0.0001	0.27 ± 0.04 (0.21, 0.34)	0.55 ± 0.11 (0.41, 0.74)	0.0004
	Outpatient	0.19 ± 0.014 (0.093, 0.25)	0.27 ± 0.042 (0.19, 0.37)	0.13	0.17 ± 0.027 (0.13, 0.23)	0.34 ± 0.12 (0.19, 0.59)	0.42 ± 0.081 (0.3, 0.58)	0.0003	0.36 ± 0.032 (0.3, 0.43)	0.49 ± 0.081 (0.38, 0.65)	0.065
	All	0.28 ± 0.03 (0.22, 0.35)	0.49 ± 0.084 (0.37, 0.65)	0.0032	0.28 ± 0.042 (0.21, 0.37)	0.56 ± 0.19 (0.33, 0.95)	0.9 ± 0.16 (0.69, 1.2)	<0.0001	0.77 ± 0.077 (0.64, 0.93)	1.3 ± 0.21 (1, 1.7)	0.0016
Non-respiratory Visits in 12 months visits/person/year	Hospital	0.14 ± 0.046 (0.085, 0.22)	0.33 ± 0.12 (0.2, 0.55)	0.013	0.092 ± 0.042 (0.054, 0.16)	0.063 ± 0.063 (0.011, 0.34)	0.38 ± 0.16 (0.24, 0.6)	0.0002	0.19 ± 0.046 (0.14, 0.26)	0.17 ± 0.069 (0.096, 0.3)	0.76
	ED	0.42 ± 0.1 (0.29, 0.61)	0.67 ± 0.2 (0.41, 1.1)	0.15	0.29 ± 0.089 (0.16, 0.44)	0.13 ± 0.13 (0.024, 0.65)	0.59 ± 0.24 (0.36, 0.98)	0.036	0.42 ± 0.094 (0.31, 0.56)	0.73 ± 0.22 (0.49, 1.1)	0.021
	Outpatient	3.0 ± 0.19 (2.6, 3.4)	3.6 ± 0.4 (3, 4.4)	0.078	2.7 ± 0.17 (2.3, 3)	2.9 ± 0.41 (2.1, 4.1)	3.1 ± 0.34 (2.6, 3.9)	0.42	3 ± 0.18 (2.7, 3.3)	3.1 ± 0.28 (2.6, 3.7)	0.73
	All	3.5 ± 0.26 (3.1, 4)	4.6 ± 0.56 (3.8, 5.7)	0.028	3.1 ± 0.24 (2.6, 3.5)	3.1 ± 0.46 (2.1, 4.6)	4.1 ± 0.55 (3.3, 5.1)	0.096	3.6 ± 0.25 (3.2, 4.1)	4 ± 0.44 (3.3, 4.9)	0.36
Non-respiratory Visits in 60 months visits/person/year	Hospital	0.099 ± 0.023 (0.069, 0.14)	0.18 ± 0.047 (0.12, 0.28)	0.038	0.097 ± 0.025 (0.068, 0.14)	0.038 ± 0.027 (0.0083, 0.17)	0.15 ± 0.047 (0.092, 0.25)	0.97	0.12 ± 0.024 (0.093, 0.16)	0.13 ± 0.03 (0.08, 0.2)	0.91
	ED	0.37 ± 0.059 (0.28, 0.49)	0.57 ± 0.12 (0.4, 0.83)	0.077	0.3 ± 0.053 (0.23, 0.4)	0.23 ± 0.068 (0.097, 0.52)	0.46 ± 0.11 (0.31, 0.68)	0.14	0.33 ± 0.024 (0.26, 0.43)	0.46 ± 0.12 (0.32, 0.66)	0.15
	Outpatient	2.5 ± 0.15 (2.3, 2.8)	3.2 ± 0.25 (2.7, 3.7)	0.034	2.4 ± 0.14 (2.1, 2.7)	2.1 ± 0.37 (1.6, 2.9)	2.5 ± 0.21 (2.1, 3)	0.67	2.5 ± 0.12 (2.2, 2.7)	2.6 ± 0.24 (2.2, 3.1)	0.62
	All	3 ± 0.2 (2.7, 3.4)	3.9 ± 0.32 (3.3, 4.6)	0.014	2.8 ± 0.018 (2.5, 3.2)	2.4 ± 0.44 (1.7, 3.4)	3.1 ± 0.3 (2.6, 3.8)	0.38	2.9 ± 0.16 (2.6, 3.3)	3.2 ± 0.33 (2.7, 3.8)	0.42

Notes: Data are mean ± SEM (95% confidence intervals).

* ANOVA comparing prescription level;

** 2df ANOVA comparing prescription level.

Abbreviations: Hospital, hospitalization; ED, emergency department; Outpatient, outpatient visit; All, total health care encounters.