Cost-Effectiveness of Domiciliary High Flow Nasal Cannula Treatment in COPD Patients with Chronic Respiratory Failure

Figures & data

Table 1 Background Information on Total Study Population at Baseline

Study Population	HFNC-Treated (n=100)	Controls (n=100)	Raw Between-Group Difference	P-value for Group Difference
Gender, female, n	56	63	−7	NS
Age, years	71.0 (8.2)	70.4 (9.0)	0.6	NS
Treated with LTOT prior to inclusion, months	28.9 (32.6)	33.5 (30.6)	−4.6	NS
FEV1%	29.8 (12.6)	31.8 (12.9)	−1.8	NS
Smoking status, n, never/ present /former	1/14/85	0/26/74	1/-12/11	NS
Pack-years	41.7 (17.8)	40.5 (19.5)	1.2	NS
mMRC score	3.3 (0.9)	2.9 (0.9)	0.4	0.008
Total SGRQ score	63.1 (14.5)	60.8 (13.4)	2.3	NS
Exacerbations in year preceding inclusion	3.2 (3.1)	2.9 (2.8)	0.3	NS
Number of admissions in year preceding inclusion	1.08 (1.53)	0.89 (1.48)	0.18	NS
Days of admission in year preceding inclusion	7.40 (11.21)	5.27 (8.66)	2.13	NS
Number of ER visits in year preceding inclusion	0.02 (0.01)	0.02 (0.01)	0	NS
Costs in year preceding inclusion, excl. municipality costs (£)*	6146 (5410)	5346 (5351)	800	NS
Municipality costs in year preceding inclusion (£)	1696 (2402)	1998 (2054)	−302	NS

Notes: Results presented as mean with standard deviation (SD) unless otherwise stated. The table has partially been reproduced from a previously published paper with permission from copyright holder.¹⁹ *Variable has no missing values. Data were not complete for the following variables: SGRQ (HFNC-treated: n=97, control: n=99), Municipality costs in year preceding treatment: (HFNC-treated: n=51, control: n=49)

Abbreviations: ER, emergency room; FEV1, forced expiratory volume in the first second; GP, general practitioner; HFNC, humidified high-flow nasal cannula; LTOT, long term oxygen treatment; SGRQ, St George Respiratory Questionnaire.

Table 2 Non-Imputed and Unadjusted EQ-5D-3L Utility Values for the HFNC-Treated Group and the Control Group at Baseline, Six Months, and 12 Months of Follow-Up

	HFNC-Treated	Controls	Raw Between-Group Difference	value for Group Difference
Baseline
N	97	99
Missing (%)	1.5%	0.5%
EQ-5D-3L utility value	0.470 (0.196)	0.504 (0.174)	−0.034	0.202
Six months
N	76	79
Missing (%)	12%	11%
EQ-5D-3L utility value	0.469 (0.214)	0.433 (0.209)	0.036	0.289
12 months
N	78	82
Missing (%)	11%	9%
EQ-5D-3L utility value	0.378 (0.243)	0.372 (0.242)	0.006	0.894

Notes: Patients dying during the study were assigned an EQ-5D-3L utility value of zero, and hence are not listed as missing. Values are presented as mean with standard deviation (SD).

Abbreviation: HFNC, humidified high-flow nasal cannula.

Table 3 Non-Imputed and Unadjusted Mean Resource Utilization per Patient for the HFNC-Treated Group and the Control Group Over the 12-Month Follow-Up and Applied Unit Costs

Category	HFNC-Treated	Controls	Raw Between-Group Difference	P-value for Group Difference	Unit	Unit Cost
Mean resource utilization (SE) per patient
Primary care
Number of general practitioner contacts	33.00 (2.24)	33.66 (2.39)	−0.66	0.99	Per contact	Tariffs from collective agreement^Citation31
Secondary care
Number of hospital admissions	0.87 (0.14)	0.81 (0.13)	0.06	0.63	Per contact	DRG value of contact^Citation32
Number of hospital bed days	6.14 (1.18)	6.06 (1.04)	0.08	0.73	Per contact	Included in DRG value of contact^Citation32
Number of hospital ER visits	0.01 (0.01)	0.05 (0.03)	−0.04	0.31	Per contact	DRG value of contact^Citation32
Number of hospital outpatient visits	1.21 (0.09)	1.61 (0.14)	−0.40	0.11	Per contact	DRG value of contact^Citation32
Medicine
Number of packages of prescription drugs	39.56 (2.36)	43.92 (2.87)	−4.36	0.26	Per package	Pharmacy consumer price^Citation33
Municipality care
Hours of home nurse care	5.47 (1.19)	4.94 (1.05)	0.53	0.64	Per hour	National average effective hourly wage rate (£32)^Citation34
Hours of in-home assistance	27.58 (7.65)	31.67 (7.44)	−4.09	0.48	Per hour	National average effective hourly wage rate (£28)^Citation34
Hours of cleaning	5.33 (1.30)	8.48 (1.54)	−3.15	0.12	Per hour	National average effective hourly wage rate (£23)^Citation34
Hours of training/rehabilitation	2.70 (0.89)	2.02 (0.55)	0.68	0.80	Per hour	National average effective hourly wage rate (£32)^Citation34

Notes: Data are complete for all categories except for data on resource consumption related to municipality care (50% missing).

Abbreviations: DRG, diagnosis-related grouping; ER, emergency room; HFNC, humidified high-flow nasal cannula; SE, standard error.

Table 4 Unadjusted Mean Costs (£) per Patient in the HNFC-Treated Group and the Control Group Over the 12-Month Follow-Up Presented into Cost Categories

Category	HFNC-Treated	Controls	Raw Between-Group Difference	P-value for Group Difference
Mean costs (SE) per patient, £
General practitioner contacts	348.01 (26.01)	363.07 (28.73)	−15.06	0.91
Hospital admissions	3349.72 (546.67)	3045.32 (481.38)	304.40	0.60
Hospital ER visits	0.86 (0.86)	3.22 (2.12)	−2.36	0.32
Hospital outpatient visits	312.44 (23.55)	383.70 (32.56)	−71.26	0.16
Prescription medicine	1534.98 (78.96)	1653.24 (142.82)	−118.26	0.87
Municipality care* (imputed)	2129.28 (511.22)	2673.97 (374.97)	−544.69	0.29
Intervention cost
-myAirvo device**	425.69	0	425.69
-Oxygen stand**	37.81	0	37.81
-Consumables	493.50	0	493.50
-Service	278.85	0	278.85
Total cost (incl. intervention costs)	8911.09 (918.89)	8122.52 (657.35)	788.57	0.39

Notes: Data were complete for all categories except for data on costs related to municipality care (50% missing). *Covers the services of home nurse care, home assistance, cleaning, and rehabilitation. **Annuitized over a 5-year period at a discount rate of 4%.

Abbreviations: ER, emergency room; HFNC, humidified high-flow nasal cannula; SE, standard error.

Table 5 Incremental Cost-Effectiveness Ratios (ICERs) for the Base Case Analysis and Scenario Analyses

Analysis	N	Incremental Cost (£) (95% CI)	Incremental QALY (95% CI)	ICER (£ per QALY)	Probability of Being Cost-Effective at Thresholds of £20,000-£30,000/QALY
Base case analysis	200	212 (−1572;1995)	0.059 (0.017;0.101)	3605	83–92%
Scenario I
Analysis without adjustment for treatment days	200	85 (−1548;1717)	0.036 (−0.007;0.079)	892	75–83%
Scenario II
Analysis with 30% lower intervention cost	200	−172 (−1957;1613)	0.059 (0.017;0.101)	−2926	90–96%
Scenario III
Analysis with 30% higher intervention cost	200	596 (−1187;2378)	0.059 (0.017;0.101)	10,146	72–85%
Scenario IV
Complete case analysis	63	9 (−2575;2594)	0.103 (0.038;0.167)	92	91–97%

Notes: The incremental cost and incremental QALY are calculated as the difference between the HFNC group and the control group. The probability of cost-effectiveness is presented at thresholds of £20,000 and £30,000, respectively.

Abbreviations: CI, confidence interval; ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life year.

Figure 1 Incremental cost-effectiveness scatterplot based on the probabilistic sensitivity analysis for the base case analysis.

Notes: The black line illustrates acost-effectiveness threshold value of £20,000per QALY gained.

Abbreviation: QALY, quality-adjusted lifeyear.

Storgaard LH, Hockey H, Laursen BS, Weinreich UM. Long-term effects of oxygen-enriched nasal high flow treatment in COPD with chronic hypoxemic respiratory failure. Int J Chron Obstruct Pulmon Dis. 2018;13:1195–1205. doi:10.2147/COPD.S159666

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