Hospital Cost Savings for Sequential COPD Patients Receiving Domiciliary Nasal High Flow Therapy

Figures & data

Table 1 Principal Diagnosis for 413 Ward Admissions in the Period 12 Months Before Treatment and During the Study Period

		Baseline		Study Period		Total	%
ICD10^a		Control	NHF	Control	NHF
DJ441	COPD with acute exacerbation, unspecified	56	41	59	45	201	48.7%
DJ449	COPD, unspecified	16	19	22	5	62	15.0%
DJ440	COPD with LRTI	7	6	10	5	28	6.8%
DJ189	Pneumonia, unspecified	4	7	15	6	32	7.7%
DJ96x	Acute/chronic respiratory failure	3	6	15	1	25	6.1%
Other^b		17	19	13	16	65	15.7%
Total		103	98	134	78	413

Notes: ^aBased on Danish notation of ICD10, eg, DJ441 = J441. ^bWith secondary respiratory diagnosis or diagnoses.

Abbreviations: LRTI, acute lower respiratory infection; NHF, nasal high flow therapy.

Table 2 Comparison of the New Zealand Cohort with the Danish Cohort at Baseline

	Aotearoa New Zealand		Denmark
	Male	Female	Male	Female
Number of patients in study	10	20	81	119
Mean (sd) age (years)	71.8 (10.0)	70.5 (12.0)	72.0 (8.2)	69.8 (8.8)
Number admitted to hospital at baseline	30		99
Admissions at baseline	80		198
Weighted mean (sd) days in hospital per admission	5.69 (4.69)		5.49 (5.13)
Weighted mean (sd) hospital admission cost (NZD)	$8699 ($6351)		$8509 ($7470)

Abbreviation: sd, standard deviation.

Table 3 Hospital Admissions, Hospital Days and Admission Costs (2020 NZD) Before and After the Treatment Period Began

	Control Group		Treatment Group (NHF)
Observed data	Baseline	Study Period	Baseline	Study Period
Patients in study	100	100	100	100
Patients admitted to hospital	44	44	55	38
Hospital admissions	89	80	108	67
Hospital days	438	526	632	302
Hospital days per admission	4.92	6.58	5.80	4.51
Hospital cost	$693,211	$786,452	$965,280	$487,617
Observed annualized admissions/days/costs per patient
Admissions	0.890	0.953	1.080	0.980
Difference between study period and baseline		0.063		−0.100
Difference between control and NHF				−0.163
Hospital days	4.38	6.26	6.32	4.42
Difference between study period and baseline		1.88		−1.90
Difference between control and NHF				−3.78
Cost	$6932	$9366	$9653	$7135
Difference between study period and baseline		$2434		-$2518
Difference between control and NHF				-$4951
Modeled costs per patient year^a
Cost	$6512	$9565	$9443	$6961
Difference between study period and baseline		$3053		-$2482
Difference between control and NHF (95% CI, -$11,034 to -$36) (p<0.05)				-$5535

Note: ^a Weighted by time on randomized treatment.

Abbreviation: NHF, nasal high flow.

Table 4 Costs of the NHF Device Assuming Fulltime Use for 12 Months

Item	Annual Cost		Comment
	Patient	DHB
Capital cost^a		$540	Includes setup and home water chamber
Electricity	$66		0.13kWh/d, 5.6h, 365d, 25c/kWh
Consumables^b		$736	Air filters, heated breathing tube, nasal cannula
Total running costs	$66	$736

Note: ^aCapital cost amortized over 5 years at an interest rate of 5% per annum to give $594. ^b6 air filters (900PT913); 6 heated breathing tubes (900PT560); 12 nasal cannulae (Optiflow+E).

Abbreviation: DHB, District Health Board.

Table 5 Predicted Hospital Budget Impact per Device Over 5 Years (2020 $NZ)

	Year 1	Years 1–5
		Undiscounted	Discounted at 5% pa
Cost inputs
Capital cost	$594	$2970	$2700
Running costs^a,c	$662	$3312	$3011
Cost offset^b,c	-$4982	-$24,908	-$22,646
Net cost
Base case (usage 90%)	-$3725	-$18,626	-$16,934
Sensitivity analyses on net cost
Cost offset (+95% CI)	$1224	$6118	$5562
Cost offset (−95% CI)	-$8674	-$43,371	-$39,433
High intervention cost (+20%)	-$3474	-$17,369	-$15,792
Low intervention cost (−20%)	-$3976	-$19,882	-$18,077
High hospital admission cost (+20%)	-$4721	-$23,607	-$21,464
Low hospital admission cost (−20%)	-$2729	-$13,644	-$12,405
Scenario analyses
Usage 95%	-$3965	-$19,826	-$18,025
Usage 85%	-$3485	-$17,426	-$15,844

Note: ^aRunning costs vary by usage ($736 for 12 months fulltime). ^bCost savings due to hospital admissions averted. ^cAt 90% usage over time.