Health care utilization, costs, and readmission rates associated with hyponatremia.

PURPOSE: Hyponatremia is associated with higher morbidity and mortality rates among hospitalized patients. Our study evaluated health care utilization and associated costs of patients hospitalized with a primary diagnosis of hyponatremia. METHODS: Hospitalized patients with a primary discharge diagnosis of hyponatremia (aged ≥ 18 years) were identified from the Premier Perspective™ database (January 1, 2007-March 31, 2010) and matched to non-hyponatremic (non-HN) patients using a combination of exact patient characteristic matching and propensity score matching. Univariate and multivariate statistics were used to compare hospital resource usage, costs, and 30-day readmission rates between cohorts. RESULTS: Hospital length of stay (LOS) (± standard deviation) (3.78 ± 3.19 vs 3.54 ± 3.26 days; P < 0.001) and cost ($5396 ± $6500 vs $4979 ± $6152; P < 0.001 for the hyponatremic [HN] and non-HN patient cohorts, respectively) were greater for the HN cohort, but intensive care unit (ICU) costs ($3554 ± $6463 vs $3484 ± $8510; P = 0.828) and ICU LOS (2.37 ± 3.47 vs 2.52 ± 3.87; P = 0.345) did not differ between cohorts. The ICU admission rate (7.9% vs 4.4%; P < 0.001), as well as the 30-day readmission rate (12.1% vs 2.9%; P < 0.001) were greater for the HN cohort. After adjustment for key patient characteristics, hyponatremia was associated with a 7.6% increase in hospital LOS, an 8.9% increase in hospital costs, and a 9% increase in ICU costs. Hyponatremia was associated with an increased risk of ICU admission (odds ratio, 1.89, confidence limits, 1.72, 2.07; P < 0.001) and 30-day hospital readmission for hyponatremia (odds ratio, 4.76; confidence limits, 4.31, 5.26; P < 0.001). CONCLUSION: Compared with non-HN patients, patients with a primary diagnosis of hyponatremia use a greater amount of hospital resources and represent a challenge to hospital profitability due to the increased likelihood of 30-day readmission.

Healthcare resource burden associated with hyponatremia among patients hospitalized for heart failure in the US.

OBJECTIVE: To evaluate the burden of hyponatremia in terms of hospital resource utilization, costs, and 30-day hospital readmission among patients hospitalized for heart failure (HF) in routine clinical practice. METHODS: Hyponatremic (HN) patients (≥18 years of age) with HF discharged between January 2, 2007 and March 31, 2010 were selected from the Premier Hospital Database and matched to non-HN HF patients using exact and propensity score matching. Univariate and multivariate statistics were utilized to compare hospital resource utilization (total and intensive care unit (ICU)) and associated costs and 30-day hospital readmission among cohorts. RESULTS: The study population included 51,710 subjects (HN = 25,855, non-HN = 25,855). In comparison to the non-HN cohort, length of stay (LOS) (7.7 ± 8.3 vs 6.3 ± 7.6 days, p < 0.001), hospitalization cost ($13,339 ± $19,273 vs $10,475 ± 15,157, p < 0.001), ICU LOS (4.9 ± 5.4 vs 4.2 ± 5.4 days, p < 0.001) and ICU cost ($7195 ± $9522 vs $5618 ± 10,919, p < 0.001) as well as rate of 30-day readmission (all cause: 25.3% vs 22.2%, p < 0.001; hyponatremia-related: 21.4% vs 5.0%, p < 0.001) were greater for the HN cohort. After adjustment, hyponatremia was associated with a 21.5% increase in hospital LOS, a 25.6% increase in hospital cost, a 13.7% increase in ICU LOS and a 24.6% increase in ICU cost. Additionally, hyponatremia was associated with increased risk of ICU admission (Odds Ratio (OR) = 1.58, [CI = 1.37, 1.84], p < 0.001) and 30-day hospital readmission (all cause: OR = 1.19, [CI = 1.14, 1.24], p < 0.001; hyponatremia-related: 5.10 [CI = 4.77, 5.46], p < 0.001). LIMITATIONS: Laboratory data for serum sodium level are not available in the Premier database and the severity of hyponatremia could not be established, although several patient variables were controlled for in this study by exact and propensity score matching techniques. CONCLUSIONS: Hyponatremia in HF patients is a predictor of increased hospital resource use and represents a potential target for intervention to reduce healthcare expenditures.

Hyponatremia-associated healthcare burden among US patients hospitalized for cirrhosis.

INTRODUCTION: Hyponatremia is a frequent comorbid condition of patients hospitalized for cirrhosis and a predictor of disease severity and mortality. This study evaluated the healthcare burden of hyponatremia among patients hospitalized for cirrhosis in the real world. METHODS: Hyponatremic (HN) patients (>-18 years of age) with cirrhosis were identified using the Premier Hospital Database (January 1, 2007 to March 31, 2010) and matched to non-HN patients with cirrhosis using a combination of exact patient characteristics and propensity score matching. Univariate and multivariate statistics were utilized to compare hospital resource utilization, cost, and 30-day hospital re-admission among patient cohorts. RESULTS: The study population included 21,864 subjects (HN 10,932; non-HN 10,932). The hospital length of stay (LOS) (7.63 ± 7.4 vs. 5.89 ± 6.2 days; P < 0.001), hospital cost ($13,842 ± $20,702 vs. $11,140 ± $20,562; P < 0.001), intensive care unit (ICU) LOS (4.58 ± 4.7 vs. 3.59 ± 4.4 days; P < 0.001), and ICU cost ($7,038 ± $7,781 vs. $5,360 ± $7,557; P < 0.001) were greater for the HN cohort, as was the 30-day re-admission rate (all cause: 31.1% vs. 24.8%; P < 0.001; hyponatremia related: 25.1% vs. 11.0%; P < 0.001). Multivariate analysis showed that hyponatremia was associated with a 29.5% increase in hospital LOS, a 26.6% increase in overall hospital cost, a 23.2% increase in S. ICU LOS, and a 28.6% increase in ICU cost. Additionally, hyponatremia was associated with an increased risk of 30-day hospital re-admission (all cause: odds ratio [OR] 1.37; confidence interval [CI] 1.28-1.46; P < 0.001; hyponatremia related: OR 2.68; CI 2.48-2.90; P < 0.001). CONCLUSION: Hyponatremia in patients with cirrhosis is a predictor of increased hospital resource use and 30-day hospital re-admission, and represents a potential target for intervention to reduce healthcare expenditures for patients hospitalized for cirrhosis.

Evaluation of incremental healthcare resource burden and readmission rates associated with hospitalized hyponatremic patients in the US.

BACKGROUND: Hyponatremia is a prevalent electrolyte disorder in hospitalized patients indicative of greater morbidity and mortality. A large-scale retrospective analysis was conducted to evaluate the incremental burden of hospitalized hyponatremic (HN) versus non-HN patients in terms of hospital resource utilization, costs, and hospital readmissions in the real-world setting. METHODS: HN patients (≥18 years) were selected from the Premier Hospital Database between January 1, 2007 and March 31, 2010 and matched to a non-HN control cohort using propensity score matching. Bivariate and multivariate statistics were employed to evaluate the differences in healthcare resource utilization, costs, and hospital readmissions between patient cohorts. RESULTS: Among the matched patient cohorts, length of stay (LOS) (8.8 ± 10.3 vs 7.7 ± 8.5 days, P < 0.001), hospital admission costs ($15,281 ± $24,054 vs $13,439 ± $22,198, P < 0.001), intensive care unit (ICU) LOS (5.5 ± 7.9 vs 4.9 ± 7.1 days, P < 0.001), and ICU costs ($8525 ± $13,342 vs $7597 ± $12,695, P < 0.001) were greater for the HN versus non-HN cohort, as were hospital readmission rates 30 days postdischarge. Multivariate regressions further demonstrated that hyponatremia was associated with an increase of 10.9% for LOS, 8.2% for total hospitalization costs, 10.2% for ICU LOS, and 8.9% for ICU costs. Additionally, after multivariate adjustment, hyponatremia was associated with a 15.0% increased chance for hospital readmission 30 days postdischarge (P < 0.0001). CONCLUSIONS: Hyponatremia is an independent predictor of increased hospitalization LOS and cost, ICU admission and cost, and 30-day hospital readmission, and therefore represents a potential target for intervention to reduce healthcare expenditures for a large population of hospitalized hyponatremic patients.

Update on tolvaptan for the treatment of hyponatremia.

Tolvaptan is a member of a new class of drugs, called the vaptans, that antagonize receptors of the neurohormone arginine vasopressin. From a clinical perspective, tolvaptan has been shown to be efficacious in the treatment of hyponatremia, whether it is idiopathic or disease related, and it may have a more favorable benefit/risk profile than other treatment modalities. From an economic perspective, tolvaptan is an expensive drug for treating hyponatremia, but recent economic cost-offset models provide evidence that tolvaptan can be cost effective. The cost-effectiveness of tolvaptan is driven by reduced healthcare resource usage and hospitalization costs. More comparative research of tolvaptan versus other pharmacotherapies and analyses of patients treated with tolvaptan in the real world are needed to better determine the benefits of tolvaptan usage to patient outcome, and more accurately assess its value in the treatment of hyponatremia, an independent predictor of morbidity, mortality and cost.

Evaluation of costs associated with tolvaptan-mediated hospital length of stay reduction among US patients with the syndrome of inappropriate antidiuretic hormone secretion, based on SALT-1 and SALT-2 trials.

BACKGROUND: Two randomized clinical trials, the Study of Ascending Levels of Tolvaptan in Hyponatremia 1 and 2 (SALT-1 and SALT-2), showed that tolvaptan was an efficacious and safe therapy for the treatment of hyponatremic patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). HYPOTHESIS: This study evaluated the potential cost savings associated with tolvaptan usage based on the SALT-1 and SALT-2 trials. METHODS: Hospital length of stay (LOS) reduction associated with tolvaptan versus placebo was evaluated among hyponatremic patients with the SIADH (serum sodium < 135 mEq/L) from the combined data of the SALT-1 and SALT-2 trials. The Healthcare Cost and Utilization Project 2009 Nationwide Inpatient Sample database was used to estimate hospital cost and LOS for hospitalizations of adult (age ≥ 18 years) patients with the SIADH. A cost-offset model was constructed to evaluate the impact of tolvaptan on hospital cost and LOS, with univariate and multivariate Monte Carlo sensitivity analyses. RESULTS: In the SALT-1 and SALT-2 trials, patients with the SIADH receiving tolvaptan had a shorter hospital LOS than patients receiving placebo (4.98 vs 6.19 days, respectively). There were 21 718 hospitalizations for the SIADH identified from the Healthcare Cost and Utilization Project Nationwide 2009 Inpatient Sample database, with a mean LOS of 5.7 days and mean total hospital costs of $8667. Using an inpatient tolvaptan treatment duration of 4 days, with a daily wholesale acquisition cost of $250, the cost-offset model estimated an LOS reduction among SIADH hospitalizations of 1.11 days. The total cost offset, including tolvaptan drug cost, was estimated to be $694 per admission. The cost-neutral break-even duration of tolvaptan therapy is 6.78 days. Univariate and multivariate sensitivity analyses demonstrated consistent cost reduction associated with tolvaptan usage. Ten thousand cycles of Monte Carlo simulation showed the 95% CI for cost offset to be $73 to $1405. CONCLUSION: Based on the SALT-1 and SALT-2 trials, tolvaptan usage is associated with a shorter hospital LOS than placebo among patients with the SIADH. Including the drug cost for 4 days of inpatient tolvaptan therapy, tolvaptan is associated with an estimated mean hospital cost reduction of $694 per admission in the United States.

Evaluation of costs associated with tolvaptan-mediated length-of-stay reduction among heart failure patients with hyponatremia in the US, based on the EVEREST trial.

BACKGROUND: The Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with Tolvaptan (EVEREST) trial showed that tolvaptan use improved heart failure (HF) signs and symptoms without serious adverse events. OBJECTIVE: To evaluate the potential cost savings associated with tolvaptan usage among hospitalized hyponatremic HF patients. METHODS: The Healthcare Cost and Utilization Project (HCUP) 2008 Nationwide Inpatient Sample (NIS) database was used to estimate hospital cost and length of stay (LOS), for diagnosis-related group (DRG) hospitalizations of adult (age ≥18 years) HF patients with complications and comorbidities or major complications and comorbidities. EVEREST trial data for patients with hyponatremia were used to estimate tolvaptan-associated LOS reductions. A cost offset model was constructed to evaluate the impact of tolvaptan on hospital cost and LOS, with univariate and multivariate Monte Carlo sensitivity analyses. RESULTS: Tolvaptan use among hyponatremic EVEREST trial HF patients was associated with shorter hospital LOS than placebo patients (9.72 vs 11.44 days, respectively); 688,336 hospitalizations for HF DRGs were identified from the HCUP NIS database, with a mean LOS of 5.4 days and mean total hospital costs of $8415. Using an inpatient tolvaptan treatment duration of 4 days with a wholesale acquisition cost of $250 per day, the cost offset model estimated a LOS reduction among HF hospitalizations of 0.81 days and an estimated total cost saving of $265 per admission. Univariate and multivariate sensitivity analysis demonstrated that cost reduction associated with tolvaptan usage is consistent among variations of model variables. CONCLUSIONS: The estimated LOS reduction and cost savings projected by the cost offset model suggest a clinical and economic benefit to tolvaptan use in hyponatremic HF patients. STUDY LIMITATIONS: The EVEREST trial data may not generalize well to the US population. Clinical trial patient profiles and relative LOS reductions may not be applicable to real-world patient populations.

Blood pressure control in Hispanics in the antihypertensive and lipid-lowering treatment to prevent heart attack trial.

Historically, blood pressure control in Hispanics has been considerably less than that of non-Hispanic whites and blacks. We compared determinants of blood pressure control among Hispanic white, Hispanic black, non-Hispanic white, and non-Hispanic black participants (N=32 642) during follow-up in a randomized, practice-based, active-controlled trial. Hispanic blacks and whites represented 3% and 16% of the cohort, respectively; 33% were non-Hispanic black and 48% were non-Hispanic white. Hispanics were less likely to be controlled (<140/90 mm Hg) at enrollment, but within 6 to 12 months of follow-up, Hispanics had a greater proportion <140/90 mm Hg compared with non-Hispanics. At 4 years of follow-up, blood pressure was controlled in 72% of Hispanic whites, 69% of Hispanic blacks, 67% of non-Hispanic whites, and 59% of non-Hispanic blacks. Compared with non-Hispanic whites, Hispanic whites had a 20% greater odds of achieving BP control by 2 years of follow-up (odds ratio: 1.20; 95% CI: 1.10 to 1.31) after controlling for demographic variables and comorbidities, Hispanic blacks had a similar odds of achieving BP control (odds ratio: 1.04; 95% CI: 0.86 to 1.25), and non-Hispanic blacks had a 27% lower odds (odds ratio: 0.73; 95% CI: 0.69 to 0.78). We conclude that in all patients high levels of blood pressure control can be achieved with commonly available medications and that Hispanic ethnicity is not associated with inferior control in the setting of a clinical trial in which hypertensive patients had equal access to medical care, and medication was provided at no cost.