Nutrition therapy cost analysis in the US: pre-mixed multi-chamber bag vs compounded parenteral nutrition

Abstract

Background: Bloodstream infections (BSI) occur in up to 350 000 inpatient admissions each year in the US, with BSI rates among patients receiving parenteral nutrition (PN) varying from 1.3% to 39%. BSI-attributable costs were estimated to approximate $US12 000 per episode in 2000. While previous studies have compared the cost of different PN preparation methods, this analysis evaluates both the direct costs of PN and the treatment costs for BSI associated with different PN delivery methods to determine whether compounded or manufactured pre-mixed PN has lower overall costs.

Objective: The purpose of this study was to compare costs in the US associated with compounded PN versus pre-mixed multi-chamber bag (MCB) PN based on underlying infection risk.

Methods: Using claims information from the Premier Perspective™ database, multivariate logistic regression was used to estimate the risk of infection. A total of 44 358 hospitalized patients aged ≥18 years who received PN between 1 January 2005 and 31 December 2007 were included in the analyses. A total of 3256 patients received MCB PN and 41 102 received compounded PN. The PN-associated costs and length of stay were analysed using multivariate ordinary least squares regression models constructed to measure the impact of infectious events on total hospital costs after controlling for baseline and clinical patient characteristics.

Results: There were 7.3 additional hospital days attributable to BSI. After adjustment for baseline variables, the probability of developing a BSI was 30% higher in patients receiving compounded PN than in those receiving MCB PN (16.1% vs 11.3%; odds ratio = 1.56; 95% CI 1.37, 1.79; p < 0.0001), demonstrating 2172 potentially avoidable infections. The observed daily mean PN acquisition cost for patients receiving MCB PN was $US164 (including all additives and fees) compared with $US239 for patients receiving compounded PN (all differences p < 0.001). With a mean cost attributable to BSI of $US16 141, the total per-patient savings (including avoided BSI and PN costs) was $US1545.

Conclusion: In this analysis of real-world PN use, MCB PN is associated with lower costs than compounded PN with regards to both PN acquisition and potential avoidance of BSI. Our base case indicates that $US1545 per PN patient may be saved; even if as few as 50% of PN patients are candidates for standardized pre-mix formulations, a potential savings of $US773 per patient may be realized.

Table I

Descriptive variables at baseline: hospitals

Table II

Descriptive variables at baseline: patients and treatment

Fig. 1

Bloodstream infection rates in the pre-mixed multi-chamber bag and compounded parenteral nutrition (PN) groups. Odds ratio for observed rate = 1.72; 95% CI1.59,1.85; p < 0.0001. Odds ratio for adjusted rate = 1.56; 95% CI 1.37, 1.79; p<0.0001.

Fig. 2

Savings per patient by appropriateness for pre-mixed multichamber bag (MCB) parenteral nutrition (PN). Extreme sensitivity analysis (absolute lower and upper limits) achieved by adding sensitivities of daily PN savings, bloodstream infection (BSI)-attributable costs and avoidable BSI. Appropriateness for standardized PN via MCB based on potential needs of each patient population.