Economic Assessment of Home-Based COPD Management Programs

Figures & data

Figure 1.  Exemplary schematic of a home-based exacerbation management program.

Table 1.  Definition of the two major components of a home-based COPD exacerbation management program

TEST	The home-based program to monitor and detect possible exacerbations. It includes one or more of the items listed in the right column	✓ Activity/ Biomarker monitoring ✓ Questionnaires (symptom monitoring) ✓ Daily data review by smart algorithms and referral to a case manager when they exceed a defined threshold
TREAT	The early exacerbation intervention based upon the detection of the exacerbation (as above)	✓ Healthcare professionals to review data as appropriate ✓ Telephone triage ✓ Personnel home visit (if needed) ✓ Initiation of home medication package

Table 2.  Definition of patient stratification and their source of data assumptions

	Definition	Freq	Assumption/Data source
Level I	Rare exacerbators without prior AE admission	< 1 exac per year^†	ECLIPSE study (7)
Level II	Infrequent exacerbators without prior AE admission	1–2 exac per year^†	ECLIPSE study (7)
Level III	Frequent exacerbators without prior AE admission	2–4 exac per year^†	ECLIPSE study (7)
Level IV	Patients with one index AE admission	75% 2 admission per year, and 25% 1 admission per year	Clinical experts from UK and NL*Clinical trials (11, 12)
Level V	Patients within 3-month discharge	Same as above	Clinical experts from UK and NL*Clinical trials (11, 12)

^†One out of 8 exacerbations are AEs, or COPD induced hospital admissions.

*Assumptions are based on expert opinions data obtained via interviewing physicians with 10+ years clinical experience.

Figure 2.  Markov state diagram to model the recurrent and chronic nature of COPD. Note that only acute exacerbations (AE) leads to hospitalization.

Table 3.  Probability Estimate Per Markov Cycle (6 weeks)

Per Cycle Probability Estimate
Death rate
Hospitalized (AE)	0.10
Not Hospitalized	As a function of age*
Exacerbation rate
Level I	0.08 (0.00–0.08)
Level II	0.28(0.17–0.38)
Level III	0.70 (0.38–0.98)
Level IV	0.70 (75%) and 0.28 (25%)
Level V	0.70 (75%) and 0.28 (25%)
AE proportion
Level I–III	0.125
Level IV–V	0.67
Recovery rate
All Levels	0.95

*Data obtained from all-cause death probability of COPD patients and converted from the annual death rate to 6-week death rate.

Table 4.  Cost and utility parameters used in the Markov model

Parameter	Model Cost	Costs from reviewed literature	Utility	Loss of utility
Baseline costs^1	$2003 / year	2003 (20), 2632 (21)^3	0.549–0.748 (22)	–
Sub-acute exacerbation^2	$1068 / exacerbation	1068 (20), 631 (23),1522 (21)	0.47–0.63 (22, 24)0.47–0.71 (23)	15% (24)
Acute exacerbation^2	$11777 / exacerbation	8436 (25), 11777 (20), 8991 (26), 9407 (23), 7014 (21)	0.27–0.37 (22, 27)0.16–0.22 (23)	50% (27)

¹Annual COPD related costs incurred by a patient, regardless of the presence or absence of exacerbations.

²Additional costs incurred for each sub-acute or acute exacerbation.

³Non-adjusted costs, COPD only.

Table 5.  Using 6 parameters and 3 scenarios to define the technology efficacy and cost

Parameters	Definition	Best case Scenario	Base case Scenario	Worst case Scenario
SEN	Sensitivity of early exacerbation detection	90%	75%	60%
SPE	Specificity of early exacerbation detection	90%	75%	60%
ERR	AE reduction ratio through the early detection and intervention	0.5	0.25	0.125
LRR	Length of Stay (LOS) reduction ratio	0.28	0.28	0.14
CED^x	Cost of early detection per Markov cycle (6 weeks)	$100	$100	$100
CET	Cost of early treatment per detected exacerbation	$200	$200	$200

^xThe cost of the technology and service is a recurring cost paid regardless of whether an exacerbation occurred during this period.

SEN/SPE baseline and range is estimated by the expected performance of the technology.

ERR baseline and range is estimated from small published trials (8, 30, 31).

LRR baseline and range is estimated from small published trials (32).

CED/CET baseline and range is based on field knowledge and expert opinion on both maintenance cost and staff cost.

Figure 3.  A simplified scheme to demonstrate the Markov model of the treatment branch. Note that “Test” refers to the home exacerbation detection test and “Treat” refers to the early exacerbation treatment upon the detection of the exacerbation. False Positive (FP) will cause unneeded treatment, thus incur unnecessary cost; False Negative (FN), or missed diagnosis, will omit patients from the early treatment, thus will not reduce admissions but still incur monitoring cost.

Table 6.  Simulated impact of home-based exacerbation management

	Cohort 1				Cohort 2
		With home management^† Scenarios				With home management^† Scenarios
Parameter	Usual care	Best	Base case	Worst	Usual care	Best	Base case	Worst
Life year	11.9	+1.8	+0.48	+0.2	3.1	+1.01	+0.36	+0.22
QALY	7.44	+1.01	+0.4	+0.16	1.74	+0.62	+0.22	+0.08
Admissions*	4.0	−1.5	−0.63	−0.13	6.3	−1.9	−0.7	−0.08
Life-time cost per patient ($)	107.9K	−9.1K	−2.9K	+4.7K	91.2K	−26.0K	−16.1K	−5.1K
ICER ($/QALY)	−9009	−7250	29375	−41935	−73187	−63750

*is estimated through micro-simulation.

^†Scenario results are incremental values, compared to usual care.

Figure 4.  The service pyramid indicates the intensity of services and cost boundary of each risk level patient to be cost-saving to the payers. The table on the right shows the maximum recurring cost (per month) for home-based exacerbation management. If the service cost exceeds this number, payers would incur added costs rather than savings from the exacerbation management program.

Table 7.  Break-even service costs for different patient risk groups

	Maximum monthly service fee ($)
Patient group	Best	Base case	Worst
Cohort 1	149	96	15
Cohort 2	1077	755	302
Level V	1263	736	290
Level IV	1077	755	302
Level III	193	141	48
Level II	97	48	−8
Level I	25	−7	−39

Figure 5.  Monte Carlo simulation. Left: Cost effectiveness scatter plot. Simulated patients undergoing the usual standard-of-care are shown in blue triangles while patients undergoing the proposed home-based intervention are shown in red crosses. Right: incremental cost-effectiveness scatter plot. Cost saving has been achieved in > 95% of the simulations, and QALY gain has been achieved in 100% of the simulations.