Exploring kidney dialysis costs in the United States: a scoping review

AIMS

The increasing prevalence of end-stage renal disease (ESRD) in the United States (US) represents a considerable economic burden due to the high cost of dialysis treatment. This review examines data from real-world studies to identify cost drivers and explore areas where dialysis costs could be reduced.

METHODS

We identified and synthesized evidence published from 2016-2023 reporting direct dialysis costs in adult US patients from a comprehensive literature search of MEDLINE, Embase, and grey literature sources (e.g. US Renal Data System reports).

RESULTS

Most identified data related to Medicare expenditures. Overall Medicare spending in 2020 was $29B for hemodialysis and $2.8B for peritoneal dialysis (PD). Dialysis costs accounted for almost 80% of total Medicare expenditures on ESRD beneficiaries. Private insurance payers consistently pay more for dialysis; for example, per person per month spending by private insurers on outpatient dialysis was estimated at $10,149 compared with Medicare spending of $3,364. Dialysis costs were higher in specific high-risk patient groups (e.g. type 2 diabetes, hepatitis C). Spending on hemodialysis was higher than on PD, but the gap in spending between PD and hemodialysis is closing. Vascular access costs accounted for a substantial proportion of dialysis costs.

LIMITATIONS

Insufficient detail in the identified studies, especially related to outpatient costs, limits opportunities to identify key drivers. Differences between the studies in methods of measuring dialysis costs make generalization of these results difficult.

CONCLUSIONS

These findings indicate that prevention of or delay in progression to ESRD could have considerable cost savings for Medicare and private payers, particularly in patients with high-risk conditions such as type 2 diabetes. More efficient use of resources is needed, including low-cost medication, to improve clinical outcomes and lower overall costs, especially in high-risk groups. Widening access to PD where it is safe and appropriate may help to reduce dialysis costs.

Poor adherence to clinical practice guidelines: A call to action for increased albuminuria testing in patients with type 2 diabetes

We describe the substantial shortfall in adherence to guideline-recommended albumin-to-creatinine ratio (uACR) testing for people in the United States with type 2 diabetes. Poor compliance with current guidelines leads to delays in diagnosis-and treatment- of chronic kidney disease, which adversely affects clinical outcomes and contributes to incremental economic burden.

CKD Prevalence Among Patients With and Without Type 2 Diabetes: Regional Differences in the United States

Rationale & Objective

Regional variation in chronic kidney disease (CKD) prevalence in patients with or without type 2 diabetes mellitus (T2DM) has not been well characterized.

Study Design

Spatial and temporal comparative analysis.

Setting & Participants

MarketScan databases were used to identify patients with CKD overall and subgroups of patients with CKD with and without T2DM in the United States.

Outcomes

Spatial patterns in CKD prevalence based on year, regional clusters of CKD between years, and characteristics of patients in high-prevalence states.

Analytical Approach

Geomapping was used to visualize the state-level data of CKD prevalence generated from 2013 to 2018. We used univariate local indicators of spatial association (LISA) to evaluate geographic differences in prevalence, differential LISA for changes in CKD prevalence over time, and the χ² test to identify patient characteristics in the top-20th percentile states for the prevalence of CKD.

Results

In univariate LISA, low-low clusters, in which a state has a low CKD prevalence and the surrounding states have a below-average CKD prevalence, were observed in the northwest region throughout the study period, regardless of the T2DM status, indicating a consistently low prevalence of CKD clustered in these areas. High-high clusters were observed, regardless of the T2DM status, in the southeast region in more recent years, suggesting an increased CKD prevalence in this region.

Limitations

Health care insurance enrollment might not have been representative of the United States; the estimates were based on claims data that likely underestimated the true prevalence.

Conclusions

Geographic disparities in CKD prevalence appear increasingly magnified, with an increase in the southeastern region of the United States. This increase is especially problematic because patients with CKD in high-prevalence states experience a greater likelihood of chronic conditions than those in the rest of the United States.

Changing treatment patterns in patients with stage IV non-small cell lung cancer (NSCLC) from United States community-based oncology practices

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Background: This study evaluated the shift in treatment patterns in Stage IV NSCLC following the approval of immune-oncology (IO) agents in the US. Methods: A retrospective cohort study was performed using structured data from a US community-based oncology electronic medical record (EMR) database for care received from Jan 2015-May 2018. The study sample included patients with Stage IV NSCLC, ≥18 years of age initiating first-line (1L) treatment with chemotherapy (chemo) or IO agents and classified into 3 groups: chemo alone, IO alone, or chemo+IO. Treatment patterns in 1L and treatment switch patterns in second-line (2L) are reported. A sub-group analysis of patients initiating 1L therapy during the last 6 months of the study period (Dec 2017-May 2018) was conducted to explore changes in 1L treatment patterns in the post-IO approval setting. Chart reviews were done for a subset of patients initiating 1L from Jan 2017-May 2018 to extract information on programmed cell death ligand 1 (PD-L1) testing and evaluate the association of PD-L1 expression levels with receipt of IO therapy. Results: Between Jan 2015-May 2018, 1,969 patients received 1L therapy with a chemo or IO agent. Mean age (SD) was 69.0 (10.1) years, with 44.7% female. The majority of patients (79%, n = 1570) initiated 1L therapy with chemo alone and 21% initiated IO (alone [14%, n = 271] or in combination with chemo [7%, n = 128]). Of 1L patients, 41% (n = 809) were treated with 2L therapy. Of the 1L chemo alone group, 37% (n = 580) received IO in 2L. The use of IO agents in 1L increased from 21% to 48% (n = 147) in the sub-group analysis of 305 patients initiating therapy Dec 2017-May 2018. In the subset of 62 patients whose charts were reviewed, 87% (n = 54) had their tumor tested for PD-L1, of which 37% (n = 20) had high (≥50%) expression values. The majority of high-PD-L1 patients were treated in 1L with IO alone (80%, n = 16), followed by chemo+IO (15%; n = 3), and only 5% (n = 1) received chemo alone. Conclusions: Initially, IO was used as 2L treatment for Stage IV NSCLC, but IO use shifted to 1L setting in the US by the end of 2017. The use of IO therapy alone or with chemotherapy in 1L was more likely in patients with ≥50% PD-L1 expression level.

Computerized Clinical Decision Support to Prevent Venous Thromboembolism Among Hospitalized Patients: Proximal Outcomes from a Multiyear Quality Improvement Project

Despite venous thromboembolism (VTE) policy initiatives, gaps exist between guidelines and practice. In response, hospitals implement clinical decision support (CDS) systems to improve VTE prophylaxis. To assess the impact of a VTE CDS on reducing incidence of VTE, this study used a pretest/posttest, longitudinal, cohort design incorporating electronic health record (EHR) data from one urban tertiary and level 1 trauma center, and one suburban hospital. VTE CDS was embedded into the EHR system. The study included 45,046 admissions; 171,753 patient days; and 110 VTE events. The VTE rate declined from 0.954 per 1,000 patient days to 0.434 comparing baseline to full VTE CDS. Compared to baseline, patients benefitting from VTE CDS were 35% less likely to have a VTE. VTE CDS utilization achieved 78.4% patients assessed within 24 hr from admission, 64.0% patients identified at risk, and 47.7% patients at risk for VTE with an initiated VTE interdisciplinary plan of care. CDS systems with embedded algorithms, alerts, and notification capabilities enable physicians at the point of care to utilize guidelines and make impactful decisions to prevent VTE. This study demonstrates a phased-in implementation of VTE CDS as an effective approach toward VTE prevention. Implications for future research and quality improvement are discussed as well.

Healthe Kids: an assessment of program performance and participation

Many states in the United States have mandated school health screenings for early identification and referral to professional services for a set of health conditions. Healthe Kids, a community-based program, began offering school-based health screenings to Missouri elementary schools in March 2007. The purpose of the article is to provide a description of the Healthe Kids program, including the team members, screening process, and the program's underlying technology. Further, we present data gathered during the first 5 years of the Healthe Kids program in Kansas City, Missouri, and describe improvements to the program from lessons learned and implications to school nurses and health care delivery.

Transparency in evidence evaluation and formulary decision-making: from conceptual development to real-world implementation

OBJECTIVE

Establishing a better understanding of the relationship between evidence evaluation and formulary decision-making has important implications for patients, payers, and providers. The goal of our study was to develop and test a structured approach to evidence evaluation to increase clarity, consistency, and transparency in formulary decision-making.

STUDY DESIGN

The study comprised three phases. First, an expert panel identified key constructs to formulary decision-making and created an evidence-assessment tool. Second, with the use of a balanced incomplete block design, the tool was validated by a large group of decision-makers. Third, the tool was pilot-tested in a real-world P&T committee environment.

METHODS

An expert panel identified key factors associated with formulary access by rating the level of access that they would give a drug in various hypothetical scenarios. These findings were used to formulate an evidence-assessment tool that was externally validated by surveying a larger sample of decision-makers. Last, the tool was pilot-tested in a real-world environment where P&T committees used it to review new drugs.

RESULTS

Survey responses indicated that a structured approach in the formulary decision-making process could yield greater clarity, consistency, and transparency in decision-making; however, pilot-testing of the structured tool in a real-world P&T committee environment highlighted some of the limitations of our structured approach.

CONCLUSION

Although a structured approach to formulary decision-making is beneficial for patients, health care providers, and other stakeholders, this benefit was not realized in a real-world environment. A method to improve clarity, consistency, and transparency is still needed.

Uncontrolled asthma: assessing quality of life and productivity of children and their caregivers using a cross-sectional Internet-based survey

BACKGROUND

Results of a national survey of asthmatic children that evaluated management goals established in 2004 by the National Asthma Education and Prevention Program (NAEPP) indicated that asthma symptom control fell short on nearly every goal.

METHODS

An Internet-based survey was administered to adult caregivers of children aged 6-12 years with moderate to severe asthma. Asthma was categorized as uncontrolled when the caregiver reported pre-specified criteria for daytime symptoms, nighttime awakening, activity limitation, or rescue medication based on the NAEPP guidelines. Children's health-related quality of life (HRQOL) and caregivers' quality of life (QOL) were assessed using the Child Health Questionnaire Parent Form 28 (CHQ-PF28) and caregiver's work productivity using a modified Work Productivity and Activity Impairment Questionnaire. Children with uncontrolled vs. controlled asthma were compared.

RESULTS

360 caregivers of children with uncontrolled asthma and 113 of children with controlled asthma completed the survey. Children with uncontrolled asthma had significantly lower CHQ-PF28 physical (mean 38.1 vs 49.8, uncontrolled vs controlled, respectively) and psychosocial (48.2 vs 53.8) summary measure scores. They were more likely to miss school (5.5 vs 2.2 days), arrive late or leave early (26.7 vs 7.1%), miss school-related activities (40.6 vs 6.2%), use a rescue inhaler at school (64.2 vs 31.0%), and visit the health office or school nurse (22.5 vs 8.8%). Caregivers of children with uncontrolled asthma reported significantly greater work and activity impairment and lower QOL for emotional, time-related and family activities.

CONCLUSIONS

Poorly controlled asthma symptoms impair HRQOL of children, QOL of their caregivers, and productivity of both. Proper treatment and management to improve symptom control may reduce humanistic and economic burdens on asthmatic children and their caregivers.

Uncontrolled asthma among children: impairment in social functioning and sleep

OBJECTIVE

To evaluate asthma symptom frequency, severity, and control among children with asthma and to evaluate the impact on social functioning and sleep impairment.

PATIENTS AND METHODS

Using a cross-sectional design, adult caregivers of children aged 6-12 years with moderate to severe asthma (severity based on National Asthma Education and Prevention Program guidelines) were surveyed about the child's symptoms, treatment, activity limitation, and sleep impairment. Asthma was categorized as uncontrolled if the caregiver reported any of the following of the child: experienced >2 days/week with symptoms, were awakened at night by symptoms during the preceding 4 weeks, had activity limited by a health problem, or used short-acting beta-agonist for rescue >5 times/week. Asthma not meeting any of these criteria was categorized as controlled. Social functioning and sleep impairment were assessed using questions adapted from the SleepLearnPlay instrument. Children with uncontrolled and controlled asthma were compared using t tests for continuous variables and Fisher's exact test for categorical variables. Multiple comparison adjustment using the Bonferroni procedure was made for social functioning and sleep impairment measures.

RESULTS

A total of 473 caregivers completed the survey; 360 were caregivers of children with uncontrolled asthma and 113 of children with controlled asthma. Compared with controlled asthma, a greater proportion of children with uncontrolled asthma showed avoidance across all nine social activities assessed. Children with uncontrolled asthma were significantly more likely to wake up at night with symptoms (p <.0001) and use a rescue inhaler at night (p <.0001), experience difficulty waking up in the morning (p = .0001) and getting out of bed (p = .0039), and be overly tired all day (p <.0001).

CONCLUSIONS

Uncontrolled asthma impacted functioning and sleep of children to a significantly greater degree than well-controlled asthma. Proper treatment and disease management to improve symptom control can reduce this impact on the lives of children.

The relationship between the prevalence of nighttime gastroesophageal reflux disease and disease severity

BACKGROUND

Nighttime gastrointestinal reflux disease (GERD) prevalence and severity estimates vary substantially across studies.

METHODS

We assessed nighttime GERD (NTG) prevalence and symptom frequency and severity through a web survey of US adults, using the GERD Symptom and Medication Questionnaire (GERD-SMQ), a validated symptom questionnaire. NTG was based on episodes of nighttime heartburn per week and time of occurrence. Symptom severity and impact were assessed and compared for GERD cases with and without NTG.

RESULTS

GERD prevalence among respondents (n = 2,603) was 27%. Forty-five percent of symptomatic GERD respondents had NTG. Among respondents with both daytime and nighttime symptoms, 51% reported that nighttime symptoms were more bothersome. NTG respondents reported greater disease severity compared with those without (P < 0.0001).

CONCLUSIONS

NTG symptoms are very common among those identified with GERD. People with nighttime symptoms have greater disease severity than those with exclusively or primarily daytime symptoms.

The impact of uncontrolled asthma on absenteeism and health-related quality of life

OBJECTIVE

To evaluate the impact of uncontrolled asthma on the absenteeism and health-related quality of life (HRQOL) of adults and children with asthma and the caregivers of pediatric patients.

PATIENTS AND METHODS

Patient information was obtained from datasets maintained by National Jewish Health for this cross-sectional study. Participants in the study were 12 years of age or older. Participants younger than 18 years had their information provided by caregivers. Caregivers also provided 6 months of absenteeism and QOL data. Participants were classified as having uncontrolled asthma based on a treatment and symptom guideline-based algorithm. Absenteeism was assessed from the self-reported number of work or school days missed due to asthma during the previous 6 months. HRQOL among adults was measured using the validated Marks Asthma Quality of Life Questionnaire (Marks-AQLQ) and among caregivers using the validated Pediatric Asthma Caregivers Quality of Life Questionnaire (PACQLQ). To account for the positive skew in absenteeism data, a zero-inflated Poisson regression model was used to compare group differences. HRQOL was analyzed for adults and caregivers using the Wilcoxon-Mann-Whitney test.

RESULTS

A total of 15,149 patients met the inclusion criteria for the study and were included in the analysis. Adults with uncontrolled asthma and caregivers of children with uncontrolled asthma reported significantly higher absenteeism than their controlled counterparts: 43% vs 24% adults reported missing days of work, with a median 6 days vs 3 days missed; 31% vs 16% of caregivers reported missing days of work, with 4 days vs 2 days missed; and caregivers reported that more than 70% vs 45% pediatric patients missed school, with a median of 6 days vs 4 days missed (uncontrolled vs controlled asthma, respectively). Adult uncontrolled asthmatics and caregivers of uncontrolled pediatric patients had significantly lower HRQOL as indicated by the Marks-AQLQ (scores 1.5 points higher, p < 0.001) and PACQLQ (scores < 0.5 points lower, p < 0.001), respectively.

CONCLUSIONS

Uncontrolled asthma has far-reaching impact on the productivity and quality of life of asthma patients and their caregivers. Proper assessment, treatment, and disease management to improve asthma control may reduce the impact of uncontrolled asthma on asthmatic adults, children, and the caretakers of pediatric asthmatic patients.

Review: use of electronic medical records for health outcomes research: a literature review

This review assessed the use of electronic medical record (EMR) systems in outcomes research. We systematically searched PubMed to identify articles published from January 2000 to January 2007 involving EMR use for outpatient-based outcomes research in the United States. EMR-based outcomes research studies (n = 126) have increased sixfold since 2000. Although chronic conditions were most common, EMRs were also used to study less common diseases, highlighting the EMRs' flexibility to examine large cohorts as well as identify patients with rare diseases. Traditional multi-variate modeling techniques were the most commonly used technique to address confounding and potential selection bias. Data validation was a component in a quarter of studies, and many evaluated the EMR's ability to achieve similar results previously achieved using other data sources. Investigators using EMR data should aim for consistent terminology, focus on adequately describing their methods, and consider appropriate statistical methods to control for confounding and treatment-selection bias.

Night-time and daytime atypical manifestations of gastro-oesophageal reflux disease: frequency, severity and impact on health-related quality of life

BACKGROUND

Respondents with gastro-oesophageal reflux disease (GERD) report having a variety of atypical manifestations. The relationship between these manifestations and disease severity, night-time GERD and functioning has not been determined.

AIM

To determine if atypical manifestations are related to increased disease severity, night-time GERD and decreased functioning.

METHODS

A web survey among US adults was conducted, using a validated GERD screener. Frequency of night-time and daytime typical symptoms (acid regurgitation and heartburn) and atypical manifestations were assessed. Respondents were classified as night-time GERD or daytime GERD based on typical symptom frequency. Prevalence of frequent atypical manifestations (> or =2 days or nights/week) was assessed.

RESULTS

Gastro-oesophageal reflux disease cases had a higher prevalence of each atypical manifestation (P < 0.05 for all) compared with controls. Night-time GERD respondents had a higher prevalence of atypical manifestations compared with daytime GERD respondents (P < 0.05 for most manifestations) and the prevalence of atypical manifestations increased with GERD symptom severity (P < 0.05 for most). Those with atypical manifestations reported lower functioning scores (P < 0.05 for most).

CONCLUSIONS

Respondents with typical GERD symptoms commonly report atypical manifestations, especially those with night-time symptoms and those with greater underlying GERD severity. Respondents with GERD and atypical manifestations had more impaired functioning than those with typical symptoms only.

Using the daily record of severity of problems as a screening instrument for premenstrual syndrome

OBJECTIVE

To assess symptom ratings on the first day of menses to identify women at high risk of clinically significant premenstrual syndrome (PMS) who should undergo further evaluation.

METHODS

A cohort of 697 women kept daily symptom ratings using the Daily Record of Severity of Problems (DRSP). The DRSP includes 21 symptom items grouped within 11 domains. DRSP scores on the first day of menses were calculated using the sum of all 21 items (standard method), the sum of the highest rated items within each domain (alternative method), and the sum of seven items derived from modeling. Seventy percent of the study sample was randomly assigned into a model-building set to identify optimal cutoff scores for PMS screening. The remaining 30% comprised a testing set used to compare PMS screening results to a PMS diagnosis based on two cycles of daily DRSP ratings.

RESULTS

Of the initial study sample, 388 participants (55.7%) completed two cycles of daily ratings. The prevalence of PMS was 30.4%. In the model-building set, the positive and negative predictive values of the 21-item DRSP scores were 53.8% and 83.4% using the standard method and 52.7% and 84.0% using the alternative method. Corresponding values were 55.0% and 84.9% for an abbreviated seven-item DRSP version. These results were confirmed in the testing set.

CONCLUSION

The DRSP administered on the first day of menses is an acceptable screening instrument to identify women who may have PMS.

Consequences of frequent nocturnal gastro-oesophageal reflux disease among employed adults: symptom severity, quality of life and work productivity

BACKGROUND

Effects of frequent nocturnal symptoms of gastro-oesophageal reflux disease (GERD-FNS) on health-related quality of life (HRQOL) and work productivity are not well documented.

AIM

To assess symptom severity, production loss, and HRQOL among employed adults with and without GERD-FNS.

METHODS

Using several validated outcome measures in a web survey design, GERD was pre-specified as GERD Symptom and Medication Questionnaire score >9, and > or =1 episode of heartburn or acid regurgitation during the preceding week. GERD-FNS patients were those reporting > or =2 symptom-nights during the previous week; their outcomes were compared with those of patients having minimal or no nocturnal symptoms (GERD-NNS) and vs. non-GERD controls.

RESULTS

Data were collected from 1002 GERD patients (476 GERD-FNS, 526 GERD-NNS) and 513 controls. Severe symptoms were more common, sleep abnormalities were more frequent (P < 0.0001) and SF-36 scores lower (P < 0.05, all scores) among GERD-FNS patients vs. GERD-NNS patients. GERD-related work loss was greater among those with GERD-FNS vs. GERD-NNS (P < 0.0001). Work loss and functional limitations were more pronounced when comparing GERD-FNS cases vs. non-GERD controls.

CONCLUSION

Employed adults with frequent nocturnal GERD report more severe symptoms, and are associated with impaired sleep, HRQOL and work productivity compared with controls and patients with minimal or no nocturnal symptoms.

Evolution of clinical practice guidelines: evidence supporting expanded use of medicines

Previous studies have shown that the primary factor underlying increased spending on pharmaceuticals has been the rising utilization of medications, rather than increases in unit drug price. This study examined the evolution of clinical practice guidelines to assess possible reasons for the rising drug volume. Clinical practice guidelines from 1970 to the present were reviewed for the six most prevalent treatable medical conditions/risk factors listed as priority areas by the Institute of Medicine. We searched the National Guidelines Clearinghouse, PubMed and Medline databases, and Web sites of relevant national organizations for US clinical practice guidelines published through January 2005. Information pertaining to the therapeutic regimen (eg, the frequency and duration of recommended treatment, when treatment should be initiated, the patient population for whom the guideline was intended) was abstracted and entered into evidence tables. Changes in guidelines were distributed across three themes that recommended evidence-based increases in medication use, including: (1) changes in the size of the treatable population; (2) changes in the number and type of recommended pharmaceutical therapeutic options, including movement from monotherapy to combination therapy, treatment of comorbidities, and use of newer types of medicines; and (3) changes in the therapeutic regimen, including a shift from episodic care to preventive and chronic care. Many of these changes point to an important, but not often noticed, addition of secondary prevention of disease effects to the objectives of medical care. These trends are likely to continue with important economic, clinical, and policy ramifications.

Evaluating the Criteria Used for Identification of PMS

OBJECTIVE

Criteria for defining premenstrual syndrome (PMS) were assessed by comparing a reference definition previously demonstrated to be associated with reduced health-related quality of life and impaired productivity with alternative definitions based on criteria stringency variations.

METHODS

Health-related quality of life data were collected from the Medical Outcomes Study Short Form-36 (SF-36) for women aged 18-64 years. Women maintained daily calendars of emotional and physical symptoms and work productivity. PMS prevalence and differences in health-related quality of life and work productivity between women with and without PMS were compared using alternative definitions.

RESULTS

Across criteria, PMS prevalence ranged from 19% to 30%. Regardless of the criteria used, PMS was associated with reductions in health-related quality of life, with Mental Components Subscale scores 5-12 points lower for women with PMS compared to those without PMS. Likewise, across definitions, women with PMS had greater work productivity impairment than women without PMS, netting 4 additional days with reduced productivity per month.

CONCLUSIONS

PMS prevalence varies based on criteria used to define illness. However, PMS is associated with reductions in health-related quality of life and work productivity impairment regardless of the criteria used.

Clinical and economic outcomes of Staphylococcus aureus septicemia in ESRD patients receiving hemodialysis

BACKGROUND

Serious infections are a common problem in patients with end-stage renal disease (ESRD). The purpose of this study is to identify clinical and economic consequences of hospitalizations for septicemia caused by Staphylococcus aureus in hemodialysis patients with ESRD.

METHODS

We conducted a retrospective analysis of data obtained from the US Renal Data System to determine lengths of stay and Medicare paid costs for index hospitalizations and episodes of care for patients with ESRD hospitalized with septicemia caused by S aureus. Factors associated with hospital length of stay and Medicare paid costs were examined in multivariate analysis.

RESULTS

A total of 11,572 patient admissions with septicemia caused by S aureus were included; 20.7% of patients developed 1 or more complications. Average length of stay for the index admission was 13.0 days, and 11.8% of patients were readmitted within 12 weeks for care related to S aureus. Average Medicare cost for the index admission was 17,307 dollars. Average episodic cost of care, including the index hospitalization, outpatient visits, and readmissions related to S aureus during the subsequent 12 weeks, was 20,067 dollars. S aureus--related complications were associated with greater episodic costs of care: no complications, 18,476 dollars; one complication, 25,804 dollars (P < 0.05 versus no complications); and 2 or more complications, 32,102 dollars (P < 0.05 versus no complications). In multivariate analysis, complications resulted in increased mean lengths of stay of 4 to 7 days, and complications were among the strongest predictors of total episodic costs.

CONCLUSION

Patients with septicemia caused by S aureus had costly and lengthy hospitalizations, which frequently were associated with clinically and economically important complications, including hospital readmissions.

Erythropoiesis-stimulating protein therapy and the decline of renal function: a retrospective analysis of patients with chronic kidney disease

BACKGROUND/AIMS

Previous studies have hinted at possible associations between anemia and progression of renal disease. The study objective was to determine whether treatment with erythropoiesis-stimulating proteins (ESPs) can curb the rate of decline in renal function in predialysis patients with chronic kidney disease (CKD).

METHODS

Observational, before/after analysis using electronic medical records from the Veterans Administration (VA). Included patients had at least two measurements of serum creatinine levels before and after ESP treatment initiation. The Cockcroft-Gault formula was used to derive estimates of glomerular filtration rate (GFR). Rate of renal function decline prior to and following initiation of therapy were compared.

RESULTS

One hundred and twenty two patients with renal impairment levels of Stage 3 (moderate) or Stage 4 (severe) at ESP treatment initiation were identified. Over 80% of patients initiated therapy with either Grade 1 or Grade 2 anemia. The rate of renal function decline was calculated as the slope of the least-squares linear regression line of the inverse serum creatinine over time during the pre-treatment initiation and post-treatment initiation time periods. Overall, patients experienced a slowing in the rate of renal function decline after treatment was initiated (mean pretreatment initiation rate of -0.094 dL/mg/yr versus mean post-treatment initiation rate of -0.057 dL/mg/yr).

CONCLUSION

Renal function declined at a slower rate following ESP initiation. Results are consistent with prior studies indicating delayed dialysis initiation in patients treated with ESPs. Analyses were limited by the observational study design and lack of information regarding some potential confounders. Longer-term, prospective trials are needed to determine whether ESPs slow progression of renal disease and the potential magnitude of such an effect.

Impairment in work productivity and health-related quality of life in patients with IBS

Irritable bowel syndrome (IBS) is a long-term and episodic medical disorder shown to have an impact on work productivity and health-related quality of life (QOL). The objective of this study was to assess the impact of IBS on work productivity and on health-related QOL in an employed population in the United States and to quantify the cost of these factors to the employer. A 2-phase survey was sent to the workforce of a large US bank to assess the presence of IBS among employees and to measure their work productivity (absenteeism [time lost from work] and presenteeism [reduced productivity at work]) and health-related QOL. Forty-one percent of the 1776 employees responding to both phases of the survey met the Rome II criteria for IBS. Employees with IBS reported a 15% greater loss in work productivity because of gastrointestinal symptoms than employees without IBS and had significantly lower Medical Outcomes Study Short Form 36 (SF-36) scores than those without IBS. IBS was associated with a 21% reduction in work productivity, equivalent to working less than 4 days in a 5-day workweek. Employees with IBS also had significantly lower scores on all domains of the SF-36, indicating poorer functional outcomes. Reduced work productivity and diminished QOL of these magnitudes may have substantial financial impact on employers.

A prospective assessment investigating the relationship between work productivity and impairment with premenstrual syndrome

Our objective was to assess life domain and work-related impairment in patients experiencing premenstrual syndrome (PMS). A sample of women, 18 to 45 years of age, completed the Daily Rating of Severity of Problems Form to record daily symptoms for two consecutive menstrual cycles. In the workplace, women with PMS reported higher absenteeism rates (2.5 days vs. 1.3 days; P = 0.006) and more workdays with 50% or less of typical productivity per month (7.2 days vs. 4.2 days; P < 0.0001). Women with PMS in one of two menstrual cycles reported a greater number of days with impairment in routine work, school, and household activities in comparison with women without PMS. Results indicate that PMS leads to substantial im in normal daily activities and occupational productivity and significantly increased work absenteeism.

Effectiveness of proton pump inhibitors in nonerosive reflux disease

BACKGROUND & AIMS

Little information is available about the efficacy of proton pump inhibitors (PPIs) in patients with nonerosive reflux disease (NERD). We aimed to synthesize available data and determine the effectiveness of PPIs on symptom resolution in patients with NERD.

METHODS

A systematic review of the literature identified studies reporting the effects of PPIs in patients with NERD. Heartburn resolution data were pooled across studies. The effectiveness of PPI therapy in inducing complete heartburn resolution was compared in patients with NERD vs. erosive esophagitis (EE).

RESULTS

Seven trials evaluating heartburn resolution in NERD were identified. Higher proportions of patients reported achieving sufficient heartburn resolution compared with complete heartburn resolution. The effect of PPIs on sufficient heartburn resolution was observed sooner than was complete heartburn resolution. Therapeutic gain of PPI therapy over placebo ranged from 30% to 35% for sufficient heartburn control and from 25% to 30% for complete heartburn control. Pooled response rates at 4 weeks were significantly higher for patients with EE compared with NERD (56% vs. 37%, P < 0.0001).

CONCLUSIONS

PPIs provide a more modest therapeutic gain in patients with NERD as compared with those with EE. A trend in increased therapeutic gain for NERD patients was shown throughout the 4 weeks, suggesting that 4 weeks of follow-up evaluation may be insufficient to show full therapeutic gain in this patient population.

Effectiveness of proton pump inhibitors in nonerosive reflux disease

BACKGROUND & AIMS

Little information is available about the efficacy of proton pump inhibitors (PPIs) in patients with nonerosive reflux disease (NERD). We aimed to synthesize available data and determine the effectiveness of PPIs on symptom resolution in patients with NERD.

METHODS

A systematic review of the literature identified studies reporting the effects of PPIs in patients with NERD. Heartburn resolution data were pooled across studies. The effectiveness of PPI therapy in inducing complete heartburn resolution was compared in patients with NERD vs. erosive esophagitis (EE).

RESULTS

Seven trials evaluating heartburn resolution in NERD were identified. Higher proportions of patients reported achieving sufficient heartburn resolution compared with complete heartburn resolution. The effect of PPIs on sufficient heartburn resolution was observed sooner than was complete heartburn resolution. Therapeutic gain of PPI therapy over placebo ranged from 30% to 35% for sufficient heartburn control and from 25% to 30% for complete heartburn control. Pooled response rates at 4 weeks were significantly higher for patients with EE compared with NERD (56% vs. 37%, P < 0.0001).

CONCLUSIONS

PPIs provide a more modest therapeutic gain in patients with NERD as compared with those with EE. A trend in increased therapeutic gain for NERD patients was shown throughout the 4 weeks, suggesting that 4 weeks of follow-up evaluation may be insufficient to show full therapeutic gain in this patient population.

Can change in high-density lipoprotein cholesterol levels reduce cardiovascular risk?

BACKGROUND

The cardiovascular risk reduction observed in many trials of lipid-lowering agents is greater than expected on the basis of observed low-density lipoprotein cholesterol (LDL-C) level reductions. Our objective was to explore the degree to which high-density lipoprotein cholesterol (HDL-C) level changes explain cardiovascular risk reduction.

METHODS

A systematic review identified trials of lipid-lowering agents reporting changes in HDL-C and LDL-C levels and the incidence of coronary heart disease (CHD). The observed relative risk reduction (RRR) in CHD morbidity and mortality rates was calculated. The expected RRR, given the treatment effect on total cholesterol level, was calculated for each trial with logistic regression coefficients from observational studies. The difference between observed and expected RRR was plotted against the change in HDL-C level, and a least-squares regression line was calculated.

RESULTS

Fifty-one trials were identified. Nineteen statin trials addressed the association of HDL-C with CHD. Limited numbers of trials of other therapies precluded additional analyses. Among statin trials, therapy reduced total cholesterol levels as much as 32% and LDL-C levels as much as 45%. HDL-C level increases were <10%. Treatment effect on HDL-C levels was not a significant linear predictor of the difference in observed and expected CHD mortality rates, although we observed a trend in this direction (P =.08). Similarly, HDL-C effect was not a significant linear predictor of the difference between observed and expected RRRs for CHD morbidity (P =.20).

CONCLUSIONS

Although a linear trend toward greater risk reduction was observed with greater effects on HDL-C, differences were not statistically significant. The narrow range of HDL-C level increases in the statin trials likely reduced our ability to detect a beneficial HDL-C effect, if present.

A systematic review evaluating health-related quality of life, work impairment, and healthcare costs and utilization in bipolar disorder

BACKGROUND

Bipolar disorder greatly impacts health-related quality of life (HRQoL), physical and social functioning, employment, and work productivity, and greatly increases health-care utilization and costs. Our objective was to characterize how bipolar disorder impacts HRQoL, work impairment, and health-care utilization and costs.

DATA SOURCES AND STUDY SELECTION

A systematic literature review was conducted to identify bipolar disorder studies of HRQoL, functioning, work impairment, and health-care utilization and costs. We searched Medline, ClinPSYC, and HealthSTAR for English-language articles published between January 1985 and November 2002 using MeSH headings and keywords. Additional articles were identified from references of relevant articles.

RESULTS

We identified 65 HRQoL articles, 14 work-impairment articles, and 28 utilization-and-care-cost articles. For all HRQoL instruments used, bipolar disorder patients' HRQoL was rated similarly to that of unipolar depression patients, and equal to or lower compared with patients with other chronic nonmental illnesses. Current treatments have been shown to improve HRQoL and physical and social functioning; some data indicate that management may improve selfreported work impairment and absenteeism. Bipolar disorder patients have been found to utilize health-care services more than do patients with depression or chronic medical conditions. Inpatient costs are the largest cost contributor; treatment to prevent recurrence has been shown to be the most effective way to reduce costs.

CONCLUSIONS

Bipolar disorder imposes a tremendous burden on patients and the health-care system, resulting in decreased HRQoL and increased medical and work impairment costs. Limited data suggest that appropriate management can improve HRQoL and functioning while reducing utilization and cost.

Health and economic impact of the premenstrual syndrome

OBJECTIVE

To explore the effect of the premenstrual syndrome (PMS) on health-related quality of life, health care utilization and occupational functioning.

STUDY DESIGN

A cross-sectional cohort study of women prospectively diagnosed with PMS.

RESULTS

Among women completing the survey, 28.7% were diagnosed with PMS. Women with PMS had significantly lower scores on the Mental Component Summary (MCS) and Physical Component Summary (PCS) scale scores of the Medical Outcomes Study Short Form-36 as compared to women without PMS (MCS = 42.8 vs. 49.5, P < .001, and PCS = 51.1 vs. 53.0, P = .04). Women with PMS reported reduced work productivity, interference with hobbies and greater number of work days missed for health reasons (P < .001). In addition, women with PMS experienced an increased frequency of ambulatory health care provider visits (P = .04) and were more likely to accrue > $500 in visit costs over 2 years (P < .006).

CONCLUSION

Findings from this study suggest that premenstrual symptoms significantly affect health-related quality of life and may result in increased health care utilization and decreased occupational productivity.

The burden of illness of gastro-oesophageal reflux disease: impact on work productivity

BACKGROUND

The impact of gastro-oesophageal reflux disease on work productivity has become increasingly important, as the symptoms of gastro-oesophageal reflux disease affect individuals in their productive years of life.

AIMS

To assess the impact of gastro-oesophageal reflux disease on reduced work productivity and to identify the predictors of reduced productivity.

METHODS

A sample of employed individuals reporting chronic heartburn was selected from US household mail survey respondents. Heartburn severity and frequency were recorded using a diary, and work productivity was assessed using the Work Productivity and Activity Impairment Questionnaire for Patients with Symptoms of Gastro-oesophageal Reflux Disease. Predictors of reduced productivity were evaluated.

RESULTS

Over 30% of heartburn sufferers reported reduced productivity. Individuals with symptoms of gastro-oesophageal reflux disease (n = 1003) reported 6.0% reduced productivity attributable to symptoms. Over 48% of respondents with severe symptoms reported reduced productivity, compared with 40% and 12% of respondents with moderate and mild symptoms, respectively. Using logistic regression, severity, a younger age and nocturnal symptoms were associated with increased odds of reduced productivity. In those reporting nocturnal heartburn, medication use and sleep interference increased the odds of reduced productivity.

CONCLUSIONS

Reduced work productivity is seen in a large proportion of subjects on prescription medication for gastro-oesophageal reflux disease. Symptom severity and nocturnal heartburn are significantly associated with reduced work productivity, particularly when nocturnal heartburn interferes with sleep.

Cost-effectiveness of proton-pump inhibitors for maintenance therapy of erosive reflux esophagitis

The relative cost-effectiveness of proton-pump inhibitors (PPIs) in the maintenance therapy of erosive reflux esophagitis was studied. Decision analysis was used to model the cost-effectiveness of PPIs on the basis of clinical trial results. Management decisions in the model were based on published U.S. guidelines and recommendations. Probability estimates were derived from a systematic review of the literature. The model's base-case scenario compared rabeprazole, lansoprazole, and omeprazole for the prevention of symptom recurrence over one year. Meta-analyzed estimates of efficacy were derived from trials by using a generalized logistic regression model with random effects. Medical costs for hospitalization, procedures, and office visits reflected 2000 Medicare payment; drug costs were based on 2000 average wholesale prices. Average costs per patient were comparable among the PPIs (rabeprazole, $1414; lansoprazole, $1671; and omeprazole, $1599). Rabeprazole prevented symptom recurrence in 86% of rabeprazole recipients, versus 68% for lansoprazole and 81% for omeprazole, and yielded the lowest average cost-effectiveness ratio (rabeprazole, $1637 per recurrence prevented; lansoprazole, $2439; and omeprazole, $1968). The model was robust to changes in key variables. When evaluated by decision analysis over a wide range of assumptions, rabeprazole was comparable to other PPIs in terms of cost and offered improved effectiveness for maintenance therapy of erosive reflux esophagitis.

Effect of nectar composition and nectar concentration on honey bee (Hymenoptera: Apidae) visitations to hybrid onion flowers

Floral nectar characteristics of nine inbred lines of onion (Allium cepa L.) were examined to determine their influence on the attractiveness of the onion flowers to honey bees (Apis mellifera L.). Potassium concentrations and sugar concentrations of the nectar did not significantly correlate with the number of bee visits received by an umbel. The average amount of nectar produced by both the umbels and the individual florets was significantly positively correlated with the number of bee visits. Our results suggest that selection for flowers with high nectar production may lead to a higher rate of pollination of the onion seed crop.

Traffic-related injury hospitalizations among California elderly, 1994

Traffic-related injuries among the elderly are a growing concern in most developed and many developing countries. To better understand injuries sustained by the elderly in the traffic environment, hospitalizations for traffic-related injuries among those aged 64 and over in California in 1994 were examined to determine incidence and characterize injuries. Both injury incidence and injury severity increased as age increased over 64. Males were more likely to be injured as drivers of motor vehicles, but females were more likely to be injured as passengers. Fractures and internal injuries represented 72.3% of all primary diagnoses, and total hospital charges exceeded $140 million. Efforts to reduce traffic-related injuries in the elderly and to reduce injury severity will be increasingly important as the elderly comprise a larger proportion of the population.

Deposition of Aliphatic Suberin Monomers and Associated Alkanes during Aging of Solanum tuberosum L. Tuber Tissue at Different Temperatures

The effect of temperature on suberization of potato tuber tissue was measured by diffusive resistance and quantitative chemical procedures. The optimum temperature for formation of aliphatic suberin monomers and development of resistance to water vapor conduction was 26.4 degrees C whereas alkane synthesis was optimal at 18.6 degrees C. Low temperatures (<16.6 degrees C) reduced suberin monomer production more than alkane synthesis.

Composition of Lipid-derived Polymers from Different Anatomical Regions of Several Plant Species

The composition of the aliphatics of the protective cuticular polymers from different anatomical regions from several plant species was determined by combined gas-liquid chromatography and mass spectrometry of the depolymerization products derived from the polymers. The polymer from the aerial parts of Vicia faba showed similar composition; dihydroxypalmitic acid was the major (>85%) component of the cutin covering leaves, petioles, flower petals and stem with smaller amounts of palmitic acid and omega-hydroxy palmitic acid. On the other hand, the chief components of the polymer from the tap root were omega-hydroxy C(16:0) and C(18:1) acids and/or the corresponding dicarboxylic acids. The positional isomer composition of the dihydroxy C(16) acids was shown to be dependent upon anatomical location, developmental stage, and light. Apple cutin from rapidly expanding organs (flower petal and stigma) was shown to contain predominately C(16) family acids whereas the C(18) family dominated in cutin of slower growing organs (leaf and fruit). The composition of the aliphatic components of cutin found in the seed coats of pea, corn, barley, and lettuce was found to be similar to that of the cuticular polymer of the leaves in each species.

Suberization: inhibition by washing and stimulation by abscisic Acid in potato disks and tissue culture

Wounding of potato (Solanum tuberosum L.) tubers results in suberization, apparently triggered by the release of some chemical factor(s) at the cut surface. Suberization, as measured by diffusion resistance of the tissue surface to water vapor, was inhibited by mm concentrations of indoleacetic acid, unaffected by mm concentrations of traumatic acid, severely inhibited at mum concentrations of cytokinin, but stimulated by abscisic acid (ABA) at 10(-4)m. Thorough washing of potato disks up to 3 to 4 days after cutting resulted in severe inhibition of suberization as measured both by diffusion resistance and by the amount of the octadecene diol generated by hydrogenolysis (LiAlH(4)) of the tissue. Disks washed after 4 days did not show any inhibition of suberization. High performance liquid chromatographic analysis of the wash from fresh potato disks showed that about 14 ng of ABA was released into the wash per g of tissue. The amount of ABA released increased with time up to 4 to 6 hours of washing. The maximal amount of ABA was washed out after aging for 24 hours and after 2 days of aging ABA could no longer be found in the surface wash of the disks. Addition of ABA to the media of potato tissue cultures resulted in suberin formation whereas control cultures contained little suberin. The effect of ABA on suberization in the tissue cultures was shown to be linearly concentration-dependent up to 10(-4)m and a linear increase in suberin formation was seen up to about 8 days of culture growth on the media containing 10(-4)m ABA. From these results it is proposed that during the early phase of wound-healing ABA plays a role in triggering a chain of biochemical processes which eventually (in about 3 to 4 days) result in the formation of a suberization-inducing factor, responsible for the induction of the enzymes involved in suberin biosynthesis.

Chemical Composition and Ultrastructure of Suberin from Hollow Heart Tissue of Potato Tubers (Solanum tuberosum)

The disorder of potato tubers (Solanum tuberosum var. Russet Burbank) called "hollow heart" is manifested by the occurrence of hollow regions in internal parts of the tuber. The structure and composition of the suberin from the tissue lining of these internal cavities were determined by gas chromatography and mass spectrometry of the LiAlH(4)-hydrogenolysis products. Identification of octadecene-1,18-diol as the major component and the presence of hexadecane-1,16-diol and very long chain (>C(18)) alcohols in the hydrogenolysate showed that the suberin lining the internal cavities is quite similar to that found in the periderm of external wounds and the natural skin. Electron microscopic examination showed similar lamellar structure for the suberin of hollow heart, external wound periderm, and the natural skin of potato tubers. The results show that suberin can develop in a tissue which is not exposed to the external environment.

Biochemistry of Suberization: Incorporation of [1-C]Oleic Acid and [1-C]Acetate into the Aliphatic Components of Suberin in Potato Tuber Disks (Solanum tuberosum)

Biosynthesis of the aliphatic components of suberin was studied in suberizing potato (Solanum tuberosum) slices with [1-(14)C]oleic acid and [1-(14)C]acetate as precursors. In 4-day aged tissue, [1-(14)C]oleic acid was incorporated into an insoluble residue, which, upon hydrogenolysis (LiA1H(4)), released the label into chloroform-soluble products. Radio thin layer and gas chromatographic analyses of these products showed that (14)C was contained exclusively in octadecenol and octadecene-1, 18-diol. OsO(4) treatment and periodate cleavage of the resulting tetraol showed that the labeled diol was octadec-9-ene-1, 18-diol, the product expected from the two major components of suberin, namely 18-hydroxyoleic acid and the corresponding dicarboxylic acid. Aged potato slices also incorporated [1-(14)C]acetate into an insoluble material. Hydrogenolysis followed by radio chromatographic analyses of the products showed that (14)C was contained in alkanols and alkane-alpha,omega-diols. In the former fraction, a substantial proportion of the label was contained in aliphatic chains longer than C(20), which are known to be common constituents of suberin. In the labeled diol fraction, the major component was octadec-9-ene-1,18-diol, with smaller quantities of saturated C(16), C(18), C(20), C(22), and C(24)-alpha,omega-diols. Soluble lipids derived from [1-(14)C]acetate in the aged tissue also contained labeled very long acids from C(20) to C(28), as well as C(22) and C(24) alcohols, but no labeled omega-hydroxy acids or dicarboxylic acids were detected. Label was also found in n-alkanes isolated from the soluble lipids, and the distribution of label among them was consistent with the composition of n-alkanes found in the wound periderm of this tissue; C(21) and C(23) were the major components with lesser amounts of C(19) and C(25). The amount of (14)C incorporated into these bifunctional monomers in 0-, 2-, 4-, 6-, and 8-day aged tissue were 0, 1.5, 2.5, 0.8, and 0.3% of the applied [1-(14)C]oleic acid, respectively. Incorporation of [1-(14)C]acetate into the insoluble residue was low up to the 3rd day of aging, rapid during the next 4 days of aging, and subsequently the rate decreased. These changes in the rates of incorporation of exogenous oleic acid and acetate reflected the development of diffusion resistance of the tissue surface to water vapor. As the tissue aged, increasing amounts of the [1-(14)C]acetate were incorporated into longer aliphatic chains of the residue and the soluble lipids, but no changes in the distribution of radioactivity among the alpha-omega-diols were obvious. The above results demonstrated that aging potato slices constitute a convenient system with which to study the biochemistry of suberization.

Synthesis of Suberin during Wound-healing in Jade Leaves, Tomato Fruit, and Bean Pods

The structure and composition of the aliphatic monomers of the polymeric material deposited during wound-healing of tomato fruit, bean pods, and Jade leaves were examined. After removing the cuticle-containing layer of tissue, the wounds were healed for 14 days and the resulting surface layer was excised, lyophilized, solvent-extracted, and depolymerized by hydrogenolysis with LiAlH(4) or transesterified with BF(3) in methanol. The products obtained by the chemical depolymerization were subjected to thin layer chromatography and combined gas chromatography and mass spectrometry. The major aliphatic components isolated from the hydrogenolysate of the wound polymer produced by tomato fruit were hexadecane-1,16-diol and octadec-9-ene-1,18-diol, which were shown to be derived from a 1:1 mixture of omega-hydroxy and dicarboxylic acids of the appropriate chain length by LiAlH(4) reduction. Also identified in the wound polymer were long chain (>C(20)) fatty acids and alcohols. This monomer composition is typical of suberin polymers and is in sharp contrast with that of the cutin of tomato fruit which contains dihydroxy C(16) acid as the major aliphatic component. The hydrogenolysis of the wound material from bean pods gave octadecene-1,18-diol as the major aliphatic component, and smaller amounts of hexadecane-1,16-diol and long chain alcohols. Similar treatment of the normal cuticular tissue of these pods gave hexadecane triol, as well as C(16) and C(18) alcohols. Hydrogenolysis of wound material from the Jade leaves gave octadecene-1,18-diol, C(16) and C(22) diols, as well as alcohols from C(16) to C(26), whereas similar treatment of the cutin-containing tissue from these leaves gave C(16) triol as the major aliphatic component. Thus, the major aliphatic monomers of the polymeric material deposited during the wound-healing of bean pods and Jade leaves are very similar to those of suberin, although the natural protective polymer of these tissues is cutin. From these results, it is concluded that suberization is a fundamental process involved in wound-healing in plants, irrespective of the chemical nature of the natural protective polymer of the tissue.

Structure, gas chromatographic measurement, and function of suberin synthesized by potato tuber tissue slices

The polymeric material (suberin) of the wound periderm of potato tuber slices was analyzed after depolymerization with LiAIH(4) in tetrahydrofuran or BF(3) in methanol with the use of thin layer chromatography, chemical modification, and combined gas-liquid chromatography and mass spectrometry. Fatty acids (C(16) to C(26)), fatty alcohols (C(16) to C(26)), octadec-9-ene-1, 18-dioic acid, and 18-hydroxy-octadec-9-enoic acid were identified to be the major components. Based on the structural information that the two bifunctional C(18) molecules constituted a major portion of suberin, a gas chromatographic method of measuring suberization was developed. This method consisted of hydrogenolysis of powdered tissue followed by thin layer chromatography and gas chromatographic measurement of octadecene-1, 18-diol as the trimethylsilyl ether. With this assay it was shown that the development of resistance to water loss by the tissue slices was directly proportional to the quantity of the bifunctional C(18) molecules, thus providing evidence that a function of suberin is prevention of water loss.