Cost and effectiveness of omega-3 fatty acid supplementation in Chinese ICU patients receiving parenteral nutrition

Figures & data

Figure 1 Model structure showing transitional probabilities, valid for the control population, derived from the hospital database.

Abbreviation: ICU, intensive care unit.

Table 1 Clinical input parameters and distributions used for the simulation

Parameter	Mean (SD)	Fixed distribution
LOS pre-ICU	5.31 (6.72) days	Weibull
LOS ICU	10.4 (10.1) days	Weibull
LOS post-ICU	14.6 (14.2) days	Weibull
Mortality in ICU	0 (0–20 in SA)%	Dirichlet
Transfer from ICU to ward	99%	Dirichlet
Discharge from ICU to home	1%	Dirichlet
Mortality in ward	7%	Dirichlet
Infection rate	20%	Beta
Duration of PN	8.3 (10) days	Weibull
RR infectiona	0.71 (0.17)	Gamma
Δ Hospital LOSa	−5.17 (1.62) days	Normal
Δ ICU LOSa	−1.92 (0.69) days	Normal

Note:

a Omegaven^® versus standard arm.

Abbreviations: ICU, intensive care unit; SD, standard deviation; SA, sensitivity analysis; PN, parenteral nutrition; RR, relative risk; LOS, length of stay.

Table 2 Unit costs from regression analyses

Parameter	Estimate (RMB)	Standard error	P
Model 1: antibiotic costs dependent on infection risk + ICU LO S +
Ward LOSa
Infection	3,895.83	346.56	,2.2e–16
ICU LOS	291.92	12.83	,2.2e–16
Ward LOS	174.49	4.81	,2.2e–16
Model 2: stay cost dependent on ICU LO S + Ward LOSb
ICU	1,969.07	89.5	,2.2e–16
Ward	1,375.56	34.43	,2.2e–16

Notes:

a Multiple R-squared: 0.8088; adjusted R-squared: 0.8082; F-statistic: 1,548 on 3 and 1,098 df;

b multiple R-squared: 0.7655; adjusted R-squared: 0.7651; F-statistic: 1,794 on 2 and 1,099 df.

Abbreviations: RMB, Renminbi; ICU, intensive care unit; LOS, length of stay; df, degrees of freedom.

Table 3 Mean (SD) unit costs (RMB) used for the simulation

Cost/day	Stay	Antibiotics	Total
Ward	1,376 (90)	174 (13)	1,550 (90)
ICU	1,969 (34)	292 (5)	2,261 (35)
PN: standard arm			655 (1)
PN: Omegaven^® arm			1,023 (1)
Infection (per episode)			3,896 (347)

Abbreviations: SD, standard deviation; RMB, Renminbi; ICU, intensive care unit; PN, parenteral nutrition.

Table 4 Cost and effectiveness results for ICU patients expressed as mean (SE)

	Omegaven^® arm	Standard arm	Differences
Effectiveness
LOS-total (days)	24 (4.0)	30 (0.3)	6.5 (4.0)
Pre-ICU ward	5.1 (0.1)	5.1 (0.1)	0 (0.0)
ICU	7.7 (1.6)	10.6 (0.2)	−2.9 (1.6)
Post-ICU ward	10.9 (3.6)	14.5 (0.2)	−3.6 (3.6)
Infections/10,000 patients	1,348 (453)	1,962 (427)	−614 (362)
Costs (RMB)
Total	49,219 (7,256)	59,836 (1,339)	−10,617 (7,202)
ICU	17,960 (3,651)	24,501 (1,112)	−6,541 (3,582)
Ward (pre-ICU)	8,185 (226)	8,185 (226)	0 (0)
Ward	16,460 (5,644)	22,095 (552)	−5,635 (5,628)
Infection	566 (185)	801 (178)	−235 (142)
PN	6,047 (526)	4,254 (39)	1,793 (525)

Abbreviations: ICU, intensive care unit; SE, standard error; LOS, length of stay, PN, parenteral nutrition.

Figure 2 Scatterplot of the incremental cost and avoided infections for the Omegaven^® versus the standard arm on a cost-effectiveness plane.

Abbreviations: O-3, Omegaven-3; ST, standard; ICER, incremental cost-effectiveness ratio; pt, patient; PSA, probabilistic sensitivity analyses.

Figure 3 Model validation: observed versus predicted hospital length of stay for the two treatment arms.

Note: Min–max lines represent the 95% CI of predicted values.
Abbreviations: CI, confidence interval; LOS, length of stay.

Figure 4 Model validation: observed versus predicted total hospital costs for the two treatment arms.

Note: Min–max lines represent the 95% CI of predicted values.
Abbreviations: CI, confidence interval; RMB, renminbi; O-3, Omegaven 3; ST, standard.