Prevalence and economic burden of hyperkalemia in the United States Medicare population

Abstract

Objective: To estimate the prevalence and economic burden of hyperkalemia in the United States (US) Medicare population.

Methods: Patients were selected from a 5% random sample of Medicare beneficiaries (01 January 2010–31 December 2014) to estimate the prevalence and economic burden of hyperkalemia. The prevalence for each calendar year was calculated as the number of patients with hyperkalemia divided by the total number of eligible patients per year. To estimate the economic burden of hyperkalemia, patients with hyperkalemia (cases) were matched 1:1 to patients without hyperkalemia (controls) on age group, chronic kidney disease [CKD] stage, dialysis treatment, and heart failure. The incremental 30-day and 1-year resource utilization and costs (2016 USD) associated with hyperkalemia were estimated.

Results: The estimated prevalence of hyperkalemia was 2.6–2.7% in the overall population and 8.9–9.3% among patients with CKD and/or heart failure. Patients with hyperkalemia had higher 1-year rates of inpatient admissions (1.28 vs. 0.44), outpatient visits (30.48 vs. 23.88), emergency department visits (2.01 vs. 1.17), and skilled nursing facility admissions (0.36 vs. 0.11) than the matched controls (all p?<?.001). Patients with hyperkalemia incurred on average $7208 higher 30-day costs ($8894 vs. $1685) and $19,348 higher 1-year costs ($34,362 vs. $15,013) than controls (both p?<?.001). Among patients with CKD and/or heart failure, the 30-day and 1-year total cost differences between cohorts were $7726 ($9906 vs. $2180) and $21,577 ($41,416 vs. $19,839), respectively (both p?<?.001).

Conclusions: Hyperkalemia had an estimated prevalence of 2.6–2.7% in the Medicare population and was associated with markedly high healthcare costs.     

Protein-energy wasting significantly increases healthcare utilization and costs among patients with chronic kidney disease: a propensity-score matched cohort study

Background: Disease-related malnutrition is highly prevalent, and has prognostic implications for patients with chronic kidney disease (CKD); however, few studies have investigated the impact of malnutrition, or protein-energy wasting (PEW), on healthcare utilization and medical expenditure among CKD patients.

Methods: Using claim data from the National Health Insurance in Taiwan, this study identified patients with CKD between 2009–2013 and categorized them into those with mild, moderate, or severe CKD. Cases with PEW after CKD was diagnosed were propensity-score matched with controls in a 1:4 ratio. Healthcare resource utilization metrics were compared, including outpatient and emergency department visits, frequency and duration of hospitalization, and the cumulative costs associated with different CKD severity.

Results: From among 347,501 CKD patients, eligible cohorts of 66,872 with mild CKD (49.2%), 27,122 with moderate CKD (19.9%), and 42,013 with severe CKD (30.9%) were selected. Malnourished CKD patients had significantly higher rates of hospitalization (p?p?=?.015 for mild CKD, p?=?.002 for severe CKD) than non-malnourished controls. Cumulative medical costs for outpatient and emergency visits, and hospitalization, were significantly higher among all malnourished CKD patients than non-malnourished ones (p?p?Conclusions: In a nationally-representative cohort, CKD patients with PEW had significantly more healthcare resource utilization and higher aggregate medical costs than those without, across the spectrum of CKD: preventing PEW in CKD patients should receive high priority if we would like to reduce medical costs.     

Cost implications of IV versus oral anti-angiogenesis therapies in patients with advanced renal cell carcinoma: retrospective claims database analysis*

ABSTRACT

Objective: Angiogenesis inhibitors (AI) are promising novel treatments for patients with renal cell carcinoma (RCC). However, IV therapy may impose infection risk from IV catheters, and will include increased costs due to administration and transportation costs. This study evaluated the incremental costs associated with IV administration of selected AI therapies (bevacizumab off-label) compared to oral therapies (sunitinib or sorafenib) for the treatment of RCC.

Methods: Patients with ≥2 RCC claims (ICD-9: 189.0, 198.0) were identified from a US commercial health insurance claims database from 1/2004 to 12/2007. Patients receiving bevacizumab (n?=?109) were matched 1:1 to patients receiving sorafenib or sunitinib, and observed from their first AI therapy claim until the last treatment date. AI, inpatient, outpatient and pharmacy costs were calculated on a per-patient per-month (PPPM) basis over the treatment period. Costs were compared between the IV AI group and each separate oral AI group using multivariate Tobit regressions for each category separately, adjusting for demographic and baseline clinical characteristics. This study assessed costs of treatment and did not evaluate the cost-effectiveness of AIs.

Results: Mean total medical costs were $13?351, $6998, and $8213 PPPM for bevacizumab, sorafenib, and sunitinib, respectively (p?<0.05 for equality). Adjusted incremental total cost for the bevacizumab group was $4951 PPPM compared to sorafenib and $4610 PPPM compared to sunitinib (both p?<?0.05). Bevacizumab patients incurred incremental PPPM outpatient services cost compared to sorafenib and sunitinib of $2772 and $2548, respectively (both p?<?0.05).

Conclusions: Assuming median progression-free survival of 8.5 months as shown for bevacizumab (Bukowski, et al., J Clin Oncol 2007), the incremental costs would be estimated at $39?188–42?080 per patient compared to those treated with sunitinib or sorafenib. Assuming similar efficacies, oral AI therapies may result in cost savings to patients and healthcare payers over IV therapies.     

Impact of secondary hyperparathyroidism on disease progression,healthcare resource utilization and costs in pre-dialysis CKD patients

ABSTRACT

Background and objectives: Secondary hyperparathyroidism (SHPT) can lead to significant morbidity, mortality, and additional healthcare resource utilization in chronic kidney disease (CKD) stage 5. The objective of this study was to examine healthcare costs and utilization, and the risks of dialysis or mortality, among pre-dialysis CKD patients with and without SHPT.

Research design and methods: This retrospective cohort study examined insurance claims from 66?644 adult, pre-dialysis, CKD patients with and without SHPT during a 72-month period. Annualized estimates of healthcare costs and utilization, and disease progression to dialysis or death following index CKD diagnosis were compared.

Results: Post-index annualized costs and inpatient healthcare resource utilization was higher in those with SHPT in both unadjusted and adjusted (controlling for gender, age, plan type, payer type, geographic region, physician specialty, pre-index co-morbidities, and pre-index total healthcare costs), and unmatched and matched analyses. Kaplan–Meier analysis demonstrated that the rate of progression to dialysis or death was higher for CKD with SHPT compared to CKD without SHPT, and Cox proportional hazard models suggested that CKD patients with SHPT were more than four to five times as likely to initiate dialysis or die as compared to CKD without SHPT.

Conclusion: SHPT in pre-dialysis CKD patients is associated with significantly greater healthcare costs, inpatient hospitalizations, and a faster rate of disease progression compared to pre-dialysis CKD without SHPT. Since observational studies are designed to demonstrate associations rather than causality, further investigation is required to confirm these findings.     

Healthcare resource utilization and costs among women diagnosed with uterine fibroids compared to women without uterine fibroids

Objective: To perform a retrospective, matched-cohort, longitudinal evaluation of annual pre- and post-diagnosis costs incurred among women with uterine fibroids (UF) (cases) compared to controls without UF.

Methods: Data were derived from the IBM Watson Health MarketScan Commercial Claims and Encounters and Medicaid Multi-State databases. Women aged 18–64?years with ≥1 inpatient or outpatient medical claim with an initial UF diagnosis (index date) from 1 January 2010 to 31 December 2014 were included. Healthcare resource utilization (HCRU) data including pharmacy, outpatient and inpatient hospital claims were collected for 1?year pre-index and ≤5?years post-index. All-cause costs (adjusted to 2017 $US) were compared between cases and controls using multivariable regression models.

Results: Analysis included 205,098 (Commercial) and 24,755 (Medicaid) case–control pairs. HCRU and total all-cause healthcare costs were higher for cases versus controls during the pre-index year and all years post-index. Total unadjusted mean all-cause costs were $1197 higher (p?<?.0001; Commercial) and $2813 higher (standardized difference 0.08; Medicaid) for cases during the pre-index year. Total adjusted mean all-cause costs in the first year post-index were $14,917 for cases versus $5717 for controls in the Commercial population, and $20,244 versus $10,544, respectively, in the Medicaid population. In Years 2–5 post-index, incremental mean adjusted total costs decreased, but remained significantly higher for cases versus controls at all time points in both populations (all p?<?.05).

Conclusions: Costs were higher for women with UF compared to women without UF during the pre-index year and over 5?years post-index; differences were greatest in the first year post-index.     

Safety,effectiveness, and health care cost comparisons among elderly patients with venous thromboembolism prescribed warfarin or apixaban in the United States Medicare population

Abstract

Objective: To compare safety, effectiveness, and healthcare costs of major bleeding (MB), clinically relevant non-major (CRNM) bleeding, recurrent venous thromboembolism (VTE), and all-cause hospitalization among elderly Medicare VTE patients prescribed warfarin vs apixaban.

Methods: Using 100% Medicare data, elderly patients prescribed apixaban or warfarin within 30 days after a VTE encounter were identified. Patients had continuous health plan enrollment and no parenteral or oral anticoagulant use ≤6 months preceding the VTE encounter. Cohorts were balanced using 1:1 propensity score matching (PSM). Cox proportional hazard models were used to assess the risk of MB, CRNM bleeding, recurrent VTE, and all-cause hospitalization. Generalized linear and two-part models were used to estimate MB-, recurrent VTE-, and all-cause related costs (per patient per month [PPPM]).

Results: In the pre-matched cohort, 25,284 (66.9%) patients were prescribed warfarin and 12,515 (33.1%) apixaban. After 1:1 PSM, 11,363 matched pairs of apixaban-warfarin patients were included for a mean follow-up of 4.0 and 4.4 months, respectively. Matched cohorts had a mean age of 78 years and mean Charlson Comorbidity Index score of 2.9. Warfarin was associated with a higher risk of MB (hazard ratio [HR]?=?1.31; 95% confidence interval [CI]?=?1.10–1.57) and CRNM bleeding (HR?=?1.31; 95% CI?=?1.19–1.43) vs apixaban. The risks of recurrent VTE (HR?=?0.96; 95% CI?=?0.70–1.33) and all-cause hospitalization (HR?=?1.05; 95% CI?=?0.99–1.12) were similar among warfarin and apixaban patients. Warfarin patients had higher MB-related ($147 vs $75; p?=?.003) and all-cause costs PPPM ($3,267 vs $3,033; p?<?.001), but similar recurrent VTE-related medical costs PPPM ($30 vs $36; p?=?.516) vs apixaban patients.

Conclusions: Warfarin was associated with significantly higher risk of MB and CRNM bleeding as well as higher MB-related and all-cause costs vs apixaban patients. Recurrent VTE risk and costs were similar among warfarin and apixaban patients.     

Warfarin time in therapeutic range and its impact on healthcare resource utilization and costs among patients with nonvalvular atrial fibrillation

Background:

Warfarin is efficacious for reducing stroke risk among patients with nonvalvular atrial fibrillation (NVAF). However, the efficacy and safety of warfarin are influenced by its time in therapeutic range (TTR).

Objective:

To assess differences in healthcare resource utilization and costs among NVAF patients with low (<60%) and high (≥60%) warfarin TTRs in an integrated delivery network (IDN) setting.

Methods:

Patients with NVAF were identified from an electronic medical record database. Patients were required to have ≥6 international normalized prothrombin time ratio (INR) tests. NVAF patients were grouped into two cohorts: those with warfarin TTR <60% (low TTR) and those with warfarin TTR ≥60% (high TTR). Healthcare resource utilization and costs were evaluated during a 12 month follow-up period. Multivariable regressions were used to assess the impact of different warfarin TTRs on healthcare costs.

Results:

Among the study population, greater than half (54%, n?=?1595) had a low TTR, and 46% (n?=?1356) had a high TTR. Total all-cause healthcare resource utilization was higher among patients in the low TTR cohort vs. the high TTR cohort (number of encounters: 70.2 vs. 56.1, p?<?0.001). After adjusting for patient characteristics, total all-cause healthcare costs and stroke-related healthcare costs were $2398 (p?<?0.001) and $687 (p?=?0.02) higher, respectively, for patients in the low TTR cohort vs. the high TTR cohort.

Limitations:

In this retrospective study, we were only able to evaluate the association and not the causality between healthcare resource utilization and costs with the different warfarin TTRs.

Conclusion:

Many warfarin-treated NVAF patients have a low warfarin TTR. NVAF patients with low vs. patients with high warfarin TTR used healthcare resources to a greater extent, which was reflected in higher healthcare costs.     

Outcomes and healthcare resource utilization associated with medically attended hypoglycemia in older patients with type 2 diabetes initiating basal insulin in a US managed care setting

Objective: To assess health outcomes and the economic burden of hypoglycemia in older patients with type 2 diabetes initiating basal insulin (BI).

Research design and methods: Medicare Advantage claims data were extracted for patients with type 2 diabetes initiating BI and patients were stratified into two groups: those with medically attended hypoglycemia during the first year of BI treatment (HG group) and those without (non-HG group). Main outcome measures were hospitalization, mortality, healthcare utilization and costs 1 year before and 1 year after BI initiation.

Results: Of 31,035 patients included (mean age 72 years [SD 9.2]), 3066 (9.9%; HG group) experienced hypoglycemia during 1 year post-BI initiation. After adjustment for demographic, comorbidity and medication history, hypoglycemia was associated with risk of hospitalization (HR 1.59; 95% CI: 1.53–1.65) and death (HR 1.50; 95% CI: 1.40–1.60). Healthcare utilization was higher pre-index and showed greater increases post-BI initiation in the HG vs. the non-HG group. Per-patient healthcare costs were substantially higher for the HG group than the non-HG group, both pre-index ($54,057 vs. $30,249, respectively) and post-BI initiation ($75,398 vs. $27,753, respectively).

Conclusions: Based on available claims data, hypoglycemia during the first year of BI treatment is associated with risk of hospitalization or death in older people, increasing healthcare utilization and costs. Due to the observational nature of this study, causality cannot be attributed, and further prospective studies into the effect of hypoglycemia on health outcomes in this population are warranted.     

Lipid-lowering agents for concurrent cardiovascular and chronic kidney disease

ABSTRACT

Introduction: Cardiovascular disease (CVD) frequently co-exists with chronic kidney disease (CKD). Patients with concomitant CVD and CKD are at very high risk of CVD events.

Areas covered: This narrative review discusses the use of hypolipidaemic drugs in patients with both CVD and CKD. Current guidelines are considered together with the evidence from randomised controlled clinical trials.

Expert opinion: Statins are the first-line lipid-lowering therapy in patients with CVD and CKD. Some statins require dose adjustments based on renal function, whereas atorvastatin does not. Ezetimibe can be prescribed in patients with CVD and CKD, usually combined with a statin. According to current guidelines, statin±ezetimibe therapy should not be initiated, but should be continued, in dialysis-treated CKD patients. Fenofibrate (dose adjusted or contra-indicated according to renal function) and omega 3 fatty acids lower triglyceride levels; whether they also exert cardiorenal benefits in patients with CVD and CKD remains to be established. The use of proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors, cholesterol-reducing nutraceuticals, bempedoic acid and apabetalone in such patients should be investigated. Patients with concomitant CVD and CKD should be treated, in terms of lipid-lowering therapy, early and intensively to minimize their very high risk and possibly, progression of CKD.     

Healthcare costs among adults with type 2 diabetes initiating saxagliptin or linagliptin: a US-based claims analysis

Objective: To compare healthcare costs of adults with type 2 diabetes (T2D) after initiation of saxagliptin or linagliptin, two antidiabetic medications in the dipeptidyl peptidase-4 inhibitor medication class.

Methods: Patients with T2D who were at least 18 years old and initiated saxagliptin or linagliptin (index date) between 1 June 2011 and 30 June 2014 were identified in the MarketScan Commercial and Medicare Supplemental Databases. All-cause healthcare costs and diabetes-related costs (T2D diagnosis on a medical claim and/or an antidiabetic medication claim) were measured in the 1 year follow-up period. Saxagliptin and linagliptin initiators were matched using propensity score methods. Cost ratios (CRs) and predicted costs were estimated from generalized linear models and recycled predictions.

Results: There were 34,560 saxagliptin initiators and 18,175 linagliptin initiators identified (mean ages 57 and 59; 55% and 56% male, respectively). Before matching, saxagliptin initiators had significantly lower all-cause total healthcare costs than linagliptin initiators (mean?=?$15,335 [SD $28,923] vs. mean =?$20,069 [SD $48,541], p?p?n?=?16,069 per cohort), saxagliptin initiators had lower all-cause follow-up costs than linagliptin initiators (CR?=?0.953, 95% CI?=?0.932–0.974, p?p?=?0.017; predicted costs?=?$3989 vs. $4159).

Conclusions: Adult patients with T2D initiating treatment with saxagliptin had lower total all-cause healthcare costs and diabetes-related medical costs over 1 year compared with patients initiating treatment with linagliptin.     

Health care costs and comorbidities for patients with inclusion body myositis

Objective: This study identifies the health care costs and utilization, as well as comorbidities, in a Medicare population of inclusion body myositis (IBM) patients.

Methods: Medicare patients aged ≥65 years with a diagnosis claim for IBM were identified and matched to a cohort of non-IBM patients based on age, sex, race, calendar year and census region. Generalized linear models were used to estimate health care costs and utilization during the follow-up period.

Results: The prevalence of IBM in this population, aged ≥65 years, was 83.7 cases per 1 million patients. Mean 1 year costs for the IBM cohort (N?=?361) were $44,838 compared to $10,182 for the matched non-IBM cohort (N?=?1805), an excess of $34,656. IBM was significantly associated with multiple unsuspected comorbidities, including hypertension (66% vs. 22%), hyperlipidemia (47% vs. 18%) and myocardial infarction (13% vs. 2%) (all p?Conclusions: IBM patients utilize more health care resources and incur higher health care costs than patients without IBM. Furthermore, IBM patients were more likely to have multiple comorbidities, including cardiovascular risk factors and events, muscle and joint pain, and pulmonary complications compared to those without IBM.

Limitations: The presence of a diagnosis code for a condition on a medical claim does not necessarily indicate the presence of the disease condition because the diagnosis code could be incorrectly entered in the database. Clinical and disease-specific parameters were not available in the claims data. Additionally, due to the observational study design, the analysis may be affected by unobserved differences between patients.     

Impact of comorbid depression or anxiety on patterns of treatment and economic outcomes among patients with diabetic peripheral neuropathic pain

ABSTRACT

Objective: The objective of this retrospective analysis was to assess the correlation of comorbid depression and/or anxiety to patterns of treatment, healthcare utilization, and associated costs among diabetic peripheral neuropathic pain (DPNP) patients, employing a large US administrative claims database.

Research design and methods: Patients under age 65 with commercial insurance and patients aged 65 and older with employer-sponsored Medicare supplemental insurance were selected for the study if they had at least one diagnosis of DPNP in 2005. The first observed DPNP claim was considered the ‘index date.’ All individuals had a 12-month pre-index and 12-month follow-up period. For both populations, two subgroups were constructed for individuals with depression and/or anxiety (DPNP-DA cohort) or without these disorders (DPNP-only cohort). Patients’ demographic characteristics, clinical characteristics, and medication use were compared over the pre-index period. Healthcare expenditures and resource utilization were measured for the post-index period. Two-part models were used to examine the impact of comorbid depression and/or anxiety on healthcare utilization and costs, controlling for demographic and clinical characteristics.

Results: The study identified 11?854 DPNP-only and 1512 DPNP-DA patients in the Medicare supplemental cohort, and 11?685 and 2728 in the commercially insured cohort. Compared to DPNP-only patients over the follow-up period, a significantly higher percentage of DPNP-DA patients were dispensed pain and DPNP-related medication. All components of healthcare utilization, except home healthcare visits and physician office visits, were more likely to be provided to DPNP-DA patients versus the DPNP-only cohort (all p?<?0.01). Controlling for differences in demographic and clinical characteristics, DPNP-DA patients had significantly higher total costs than those of DPNP-only patients for Medicare ($9134, p?<?0.01) and commercially insured patients ($11?085, p?<?0.01).

Limitations: Due to the use of a retrospective administrative claims database, limitations of this study include the potential for selection bias between study cohorts, mis-identification of DPNP and/or depression, and inability to assess indirect costs as well as use and cost of over-the-counter medications.

Conclusions: These findings indicate that the healthcare costs were significantly higher for DPNP patients comorbid with depression and/or anxiety relative to those without such disorders.