Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Does point-of-care ultrasonography improve diagnostic accuracy in emergency department patients with undifferentiated hypotension? An international randomized controlled trial from the SHOC-ED investigators

PURPOSE

Point-of-care ultrasonography (POCUS) is an established tool in the management of hypotensive patients in the emergency department (ED). We compared the diagnostic accuracy of a POCUS protocol versus standard assessment without POCUS in patients with undifferentiated hypotension.

METHODS

This was an international, multicenter randomized controlled trial included three EDs in North America and three in South Africa from September 2012 to December 2016. Hypotensive patients were randomized to early POCUS protocol plus standard care (POCUS group) or standard care without POCUS (control group). Initial and secondary diagnoses were recorded at 0 and 60 min. The main outcome was measures of diagnostic accuracy of a POCUS protocol in differentiating between cardiogenic and non-cardiogenic shock. Secondary outcomes were diagnostic performance for shock sub-types, as well as changes in perceived category of shock and overall diagnosis.

RESULTS

Follow-up was completed for 270 of 273 patients. For cardiogenic shock, the POCUS-based diagnostic approach (POCUS) performed similarly to the non-POCUS approach (control) for specificity [95.5% (89.9-98.5) vs.93.8% (87.7-97.5)]; positive likelihood ratio (17.92 vs 14.80); negative likelihood ratio (0.21 vs 0.09) and diagnostic odds ratio (85.6 vs 166.57), with a similar overall diagnostic accuracy between the two approaches [93.7% (88-97.2) vs 93.6% (87.8-97.2)]. Diagnostic performance measures were similar across sub-categories of shock.

CONCLUSION

This is the first randomized controlled trial to compare diagnostic performance of a POCUS protocol to standard care without POCUS in undifferentiated hypotensive ED patients. POCUS performed well diagnostically in undifferentiated hypotensive patients, especially as a rule-in test; however, performance did not differ meaningfully from standard assessment.

Chronotype and risk of post-menopausal endometrial cancer in the California Teachers Study

Working at night causes circadian disruption and it has been classified as a probable carcinogen. An evening chronotype, or preference for late day activity, has been shown to increase risk for several adverse health effects, such as metabolic disorders and recently, breast cancer. To further explore this emerging area of interest, we examined the association between endometrial cancer (EC) risk, another common cancer in women, and chronotype. The women in this study were members of the California Teachers Study cohort, which was established in 1995. Chronotype was reported on a subsequent questionnaire (Q5), administered in 2012-2013. The women included in this analysis were under age 90 years, were post-menopausal at Q5, and had no hysterectomy. The cancer cases, identified through linkages to the California Cancer Registry, were diagnosed between 1996 and 2014. We used unconditional logistic regression models to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of the associations between chronotype and EC diagnosis. There were 437 EC cases and 26,753 cancer-free controls included in this analysis. Controls were more likely to classify themselves as current morning chronotypes than were cases (39% and 34%, respectively). Compared to morning types, women who were definite evening types had a statistically significantly elevated OR of 1.44 (95% CI 1.09-1.91). This association was more pronounced among obese women as compared to non-obese women. For evening type compared to morning type, the OR among obese women was 2.01 (95% CI 1.23, 3.29) while the OR for non-obese women was 1.12 (95% CI 0.77, 1.63). To our knowledge, the association between EC risk and evening chronotype has not been previously reported, but is consistent with the small body of literature which suggests increased breast cancer risks among evening chronotypes. Because this study was based on a retrospective analysis in a cohort of mostly white female teachers in California, further analysis of chronotype as a potential EC risk factor should be considered in other cohorts and in prospective analyses in order to further explore this relationship.

Effects of subzero saline chilling on broiler chilling efficiency, meat quality, and microbial safety

The poultry industry has attempted to improve carcass chilling efficiency, meat quality, and product safety. The purpose of this research was to investigate the effects of subzero saline chilling on carcass chilling, breast fillet tenderness, and microbial safety. After evisceration, broiler carcasses were chilled using ice slurry control (0% NaCl/0.5°C) or subzero saline solutions (3% NaCl/-1.8°C and 4% NaCl/-2.41°C). Broiler carcasses in the subzero saline solutions were chilled efficiently and reduced the chilling time by 11% in 3% NaCl/-1.8°C and 37% in 4% NaCl/-2.41°C over the ice slurry chilling. The breast fillets of broiler carcasses in 4% NaCl/-2.41°C were significantly tenderized than those in water control (P < 0.05), with an intermediate value observed in 3% NaCl/-1.8°C. Before chilling, broiler carcasses possessed mesophilic aerobic bacteria, Escherichia coli, and total coliforms for 3.81, 0.78, and 1.86 log cfu/g, respectively, which were significantly reduced after chilling in 3% NaCl/-1.8°C or 4% NaCl/-2.41°C solution over the water control (P < 0.05), except the mesophilic aerobic bacteria. Based on these results, chilling of boiler carcass in 4% NaCl/-1.8°C solution appears to improve carcass chilling efficiency, meat tenderness, and bacterial reduction for E. coli and total coliforms.

Reciprocal interactions between sodium appetite and need-free sugar intake

Behavioral sensitization occurs during sodium appetite (expressed as sodium intake to compensate for depleted sodium) and need-free sodium intake (expressed as daily overnight sodium intake in excess of dietary sodium need). Previously, we found that a slow-onset sodium appetite protocol cross-sensitized need-free sucrose intake in sucrose-naïve adult rats. That is, a history of sodium depletion elevated later sucrose intake. The objective of the present work was, first, to investigate whether a protocol that evokes a rapid-onset (within 2 h) sodium appetite using furosemide along with a low dose captopril (Furo/Cap), also cross-sensitizes sucrose intake. Then, we investigated whether 1) sensitization of need-free 0.3 M NaCl intake interacts with need-free sucrose intake, and 2) MK-801, a glutamate NMDA receptor antagonist, inhibits cross-sensitization of sucrose intake. Groups received 3-4 Furo/Cap or vehicle treatments with 48/72-h intervals. We investigated sucrose intake in hydrated and fed conditions for 2 h/day for 5 days, starting 6-10 days after the last Furo/Cap treatment. Episodes of Furo/Cap sensitized need-free sodium intake, as expected. Similar to our prior work, the rapid-onset Furo/Cap protocol cross-sensitized sucrose intake in sucrose-naïve rats and had no persistent effect on blood biochemistry. MK-801 treatment along with Furo/Cap injections appeared to prevent cross-sensitization of sucrose consumption. Sucrose intake tests unexpectedly reduced sensitized need-free sodium intake. However, MK-801 treatment allowed a rebound in need-free sodium intake subsequent to the last sucrose intake test. The results suggest that plasticity in glutamatergic mechanisms mediate inverse and reciprocal interactions between the production of sodium appetite and sucrose intake.

An Implementation and Visualization of the Tree-Based Scan Statistic for Safety Event Monitoring in Longitudinal Electronic Health Data

INTRODUCTION

Longitudinal electronic healthcare data hold great potential for drug safety surveillance. The tree-based scan statistic (TBSS), as implemented by the TreeScan^® software, allows for hypothesis-free signal detection in longitudinal data by grouping safety events according to branching, hierarchical data coding systems, and then identifying signals of disproportionate recording (SDRs) among the singular events or event groups.

OBJECTIVE

The objective of this analysis was to identify and visualize SDRs with the TBSS in historical data from patients using two antifungal drugs, itraconazole or terbinafine. By examining patients who used either itraconazole or terbinafine, we provide a conceptual replication of a previous TBSS analyses by varying methodological choices and using a data source that had not been previously used with the TBSS, i.e., the Optum Clinformatics™ claims database. With this analysis, we aimed to test a parsimonious design that could be the basis of a broadly applicable method for multiple drug and safety event pairs.

METHODS

The TBSS analysis was used to examine incident events and any itraconazole or terbinafine use among US-based patients from 2002 through 2007. Event frequencies before and after the first day of drug exposure were compared over 14- and 56-day periods of observation in a Bernoulli model with a self-controlled design. Safety events were classified into a hierarchical tree structure using the Clinical Classifications Software (CCS) which mapped International Classification of Diseases, 9th Revision (ICD-9) codes to 879 diagnostic groups. Using the TBSS, the log likelihood ratio of observed versus expected events in all groups along the CCS hierarchy were compared, and groups of events that occurred at disproportionally high frequencies were identified as potential SDRs; p-values for the potential SDRs were estimated with Monte-Carlo permutation based methods. Output from TreeScan^® was visualized and plotted as a network which followed the CCS tree structure.

RESULTS

Terbinafine use (n = 223,968) was associated with SDRs for diseases of the circulatory system (14- and 56-day p = 0.001) and heart (14-day p = 0.026 and 56-day p = 0.001) as well as coronary atherosclerosis and other heart disease (14-day p = 0.003 and 56-day p = 0.004). For itraconazole use (n = 36,025), the TBSS identified SDRs for coronary atherosclerosis and other heart disease (p = 0.002) and complications of an implanted or grafted device (14-day p = 0.001 and 56-day p < 0.05). Use of both drugs was associated with SDRs for diseases of the digestive system at 14 days (p < 0.05) and this SDR had been observed among terbinafine users in a previous TBSS analysis with a different data source. The TreeScan^® visualization facilitated the identification of the atherosclerosis and other heart disease SDRs as well as highlighting the consistency of the SDR for diseases of the digestive system across drugs and data sources.

CONCLUSION

With the TBSS, we identified potential SDRs related to the circulatory system that may reflect the cardiac risk that was described in the itraconazole product label. SDRs for diseases of the digestive system among terbinafine users were also reported in a previous signal detection analysis, although other SDRs from the previous publications were not replicated. The TBSS visualizations aided in the understanding and interpretation of the TBSS output, including the comparisons to the previous publications. In this conceptual replication, differences in the results observed in our analysis and the previous analyses could be attributable to variation in modeling and design choices as well as factors that were intrinsic to the underlying data sources. The broad consistency, but far from perfect concordance, of our results with the known safety profile of these antifungals including the risks from the itraconazole product label supports the rationale for continued investigations of signal detection methods across differing data sources and populations.

Managing taste and odour metabolite production in drinking water reservoirs: The importance of ammonium as a key nutrient trigger

Taste and odour (T&O) compounds (most commonly 2-MIB and Geosmin) in drinking water are becoming an increasingly global problem for water management. Here, the trigger(s) for 2-MIB and Geosmin production were investigated in Plas Uchaf reservoir (North Wales, UK) with detailed water sample analysis between 2015 and 2016. Historical abstraction data from this reservoir and 4 reservoirs in Somerset (England, UK) were compared statistically using Self-Organising Map (SOM) analysis. In-reservoir measurements (2015-2016) revealed an 85% reduction in ammonium from the primary external loading source led to lower 2-MIB and Geosmin concentrations, with peak concentrations of 2-MIB declining from 60 to 21  ng l^-1 and Geosmin declining from 140 to 18  ng l^-1. No other measured water chemistry parameter showed a significant difference between years. The SOM results support the in-reservoir findings, revealing 2-MIB and Geosmin to be associated with high ammonium relative to nitrate for all 5 reservoirs. We conclude that ammonium is key for stimulating cyanobacterial productivity and production of T&O compounds. Whilst it is well understood that adequate availability of phosphorus is required for rapid growth in cyanobacteria, and hence should still be considered in management decisions, we suggest that monitoring sources and concentrations of ammonium is key for managing T&O outbreaks in drinking water reservoirs.

Implementation fidelity of a self-management course for epilepsy: method and assessment

BACKGROUND

Complex interventions such as self-management courses are difficult to evaluate due to the many interacting components. The way complex interventions are delivered can influence the effect they have for patients, and can impact the interpretation of outcomes of clinical trials. Implementation fidelity evaluates whether complex interventions are delivered according to protocol. Such assessments have been used for one-to-one psychological interventions; however, the science is still developing for group interventions.

METHODS

We developed and tested an instrument to measure implementation fidelity of a two-day self-management course for people with epilepsy, SMILE(UK). Using audio recordings, we looked at adherence and competence of course facilitators. Adherence was assessed by checklists. Competence was measured by scoring group interaction, an overall impression score and facilitator "didacticism". To measure "didacticism", we developed a novel way to calculate facilitator speech using computer software. Using this new instrument, implementation fidelity of SMILE(UK) was assessed on three modules of the course, for 28% of all courses delivered.

RESULTS

Using the instrument for adherence, scores from two independent raters showed substantial agreement with weighted Kappa of 0.67 and high percent agreement of 81.2%. For didacticism, the results from both raters were highly correlated with an intraclass coefficient of 0.97 (p < 0.0001). We found that the courses were delivered with a good level of adherence (> 50% of scored items received the maximum of 2 points) and high competence. Groups were interactive (mean score: 1.9-2.0 out of 2) and the overall impression was on average assessed as "good". Didacticism varied from 42% to 93% of total module time and was not associated with the other competence scores.

CONCLUSION

The instrument devised to measure implementation fidelity was reproducible and easy to use. The courses for the SMILE(UK) study were delivered with a good level of adherence to protocol while not compromising facilitator competence.

TRIAL REGISTRATION

ISRCTN57937389 .

Pilot study to assess effects of collection tube types and processing delay on measurements of persistent organic pollutants and lipids in human serum

Glass red top tubes (RTs), traditionally used to draw blood for biomonitoring studies, have some limitations during field sampling (e.g., tube breakage, timely processing may be difficult). This pilot study examined whether serum separation tubes (SSTs) with delayed processing time (48 h) can be used instead of red top tubes (RTs) to accommodate field conditions. Using state-of-the-art methodologies, PBDEs, PCBs, OCPs, PFCs, cholesterol and triglycerides were measured to evaluate any differences among 2 test conditions (RTs with 2h processing time; SSTs with 48 h processing time). Between the 2 test conditions, we observed high rank correlations among the measured compounds and no statistically significant differences in the levels of measured compounds. We conclude that SSTs with delayed processing time (48 h) produce similar results as RTs with short processing time (2h), suggesting that SSTs could be good substitutes for RTs for new epidemiological and biomonitoring field studies. The use of SSTs offers a tremendous opportunity for the use of samples archived in various SSTs.

Screening for severe obstructive sleep apnea syndrome in hypertensive outpatients

The authors attempted to validate a 2-stage strategy to screen for severe obstructive sleep apnea syndrome (s-OSAS) among hypertensive outpatients, with polysomnography (PSG) as the gold standard. Using a prospective design, outpatients with hypertension were recruited from medical outpatient clinics. Interventions included (1) assessment of clinical data; (2) home sleep testing (HST); and (3) 12-channnel, in-laboratory PSG. The authors developed models using clinical or HST data alone (single-stage models) or clinical data in tandem with HST (2-stage models) to predict s-OSAS. For each model, area under receiver operating characteristic curves (AUCs), sensitivity, specificity, negative likelihood ratio, and negative post-test probability (NPTP) were computed. Models were then rank-ordered based on AUC values and NPTP. HST used alone had limited accuracy (AUC=0.727, NPTP=2.9%). However, models that used clinical data in tandem with HST were more accurate in identifying s-OSAS, with lower NPTP: (1) facial morphometrics (AUC=0.816, NPTP=0.6%); (2) neck circumference (AUC=0.803, NPTP=1.7%); and Multivariable Apnea Prediction Score (AUC=0.799, NPTP=1.5%) where sensitivity, specificity, and NPTP were evaluated at optimal thresholds. Therefore, HST combined with clinical data can be useful in identifying s-OSAS in hypertensive outpatients, without incurring greater cost and patient burden associated with in-laboratory PSG. These models were less useful in identifying obstructive sleep apnea syndrome of any severity.

In-home, self-assembled sleep studies are useful in diagnosing sleep apnea in the elderly

OBJECTIVES

Obstructive sleep apnea (OSA) is common and treatable among the elderly. Yet, few older adults seek evaluation for OSA at sleep disorders centers. The authors assessed the feasibility of a two-stage screening procedure for obstructive sleep apnea syndrome (OSAS) in a community-based sample of older adults.

DESIGN

Prospective cohort study.

SETTING

Participants' domicile (in-home) and academic sleep research center.

PARTICIPANTS

There were 452 Medicare recipients residing in the greater Philadelphia metropolitan area with the complaint of daytime sleepiness.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

All participants underwent in-home unattended sleep studies that recorded airflow, and standard in-laboratory polysomnography. Additional measures included symptoms of sleep apnea, body mass index, neck circumference, age, and sex. When comparing diagnostic approaches, the best-performing single-stage model was one that combined apnea symptoms with age and neck circumference. This model had an area under the receiver operating characteristic curve (AUC) of 0.774 and negative posttest probability of 1.2%. The best-performing two-stage model combined symptoms, neck circumference, age, and sex in the first stage, followed by an unattended portable study with a corresponding AUC of 0.85 and negative posttest probability of 0.5%.

CONCLUSIONS

Unattended, self-assembled, in-home sleep studies recording airflow and respiratory effort are most useful if applied in tandem with clinical data, including a carefully obtained sleep history. This two-stage model is accurate in identifying severe OSAS in older adults and represents a practical diagnostic approach for older adults. Incorporating clinical data was vital and increased accuracy well above that of unattended studies of airflow and effort alone.

Predictors of continuous positive airway pressure use during the first week of treatment

This study aimed to identify pre-treatment and immediate early treatment factors predicting continuous positive airway pressure (CPAP) use during the first week of therapy, when the pattern of non-adherence is established. Four domains of potential predictors were examined: pre-treatment demographic and clinical factors, patients' perceived self-efficacy, treatment delivery (mask leak and bothering side effects) and immediate disease reduction (residual respiratory events and flow limitation). The Autoset™ Clinical System objectively documented daily CPAP use, mask leak, residual respiratory events and flow limitation. Ninety-one CPAP-naive patients with newly diagnosed obstructive sleep apnea were followed for 1week after treatment initiation. Mean CPAP daily use during the first week was 3.4±2.7h, with significantly lower use observed in black than non-black participants (2.7 versus 4.4h, respectively, P=0.002). Less intimacy with partners caused by CPAP was the only treatment side effect correlated with CPAP use (r=-0.300, P=0.025). Reduced CPAP use during the first week was associated simultaneously with being black, higher residual apnea-hypopnea index and the treatment side effect of less intimacy with partners. The three factors together accounted for 25.4% of the variance in the CPAP use (R(2) =0.254, P<0.01). These data suggest the need to assess the impact of CPAP on intimacy and troubleshooting aspects of the treatment that interfere with sexual relationships. Assessing the presence of residual respiratory events may be important in promoting CPAP adherence. The association of race and CPAP use needs to be explored further by including more socioeconomic information.

Noninferiority of functional outcome in ambulatory management of obstructive sleep apnea

RATIONALE

Home portable monitor testing is increasingly being used to diagnose patients with obstructive sleep apnea (OSA) and to initiate them on continuous positive airway pressure (CPAP) treatment.

OBJECTIVES

To compare functional outcome and treatment adherence in patients who receive ambulatory versus in-laboratory testing for OSA.

METHODS

Veterans with suspected OSA were randomized to either home testing or standard in-laboratory testing. Home testing consisted of a type 3 portable monitor recording followed by at least three nights using an automatically adjusting positive airway pressure apparatus. Participants diagnosed with OSA were treated with CPAP for 3 months.

MEASUREMENTS AND MAIN RESULTS

We measured the change in Functional Outcomes of Sleep Questionnaire score, with an a priori noninferiority delta of -1, and the mean daily hours of objectively measured CPAP adherence, with an a priori noninferiority delta of -0.75 hour/day. Of the 296 subjects enrolled, 260 (88%) were diagnosed with OSA, and 213 (75%) were initiated on CPAP. Mean ± SD functional outcome score improved 1.74 ± 2.81 in the home group (P < 0.001) and 1.85 ± 2.46 in the in-laboratory group (P < 0.0001). The lower bound of the one-sided 95% noninferiority confidence interval was -0.54. Mean ± SD hours of daily CPAP adherence were 3.5 ± 2.5 hours/day in the home group and 2.9 ± 2.3 hours/day in the in-laboratory group (P = 0.08). The lower bound of the one-sided 95% noninferiority confidence interval was 0.03.

CONCLUSIONS

Functional outcome and treatment adherence in patients evaluated according to a home testing algorithm is not clinically inferior to that in patients receiving standard in-laboratory polysomnography.

Obstructive sleep apnea in patients undergoing bariatric surgery--a tertiary center experience

BACKGROUND

The patient population that is evaluated for bariatric surgery is characterized by a very high body mass index (BMI). Since obesity is the most important risk factor for obstructive sleep apnea (OSA), sleep disordered breathing is highly prevalent in this population. If undiagnosed before bariatric surgery, untreated OSA can lead to perioperative and postoperative complications. Debate exists whether all patients that are considered for bariatric surgery should undergo polysomnography (PSG) evaluation and screening for OSA as opposed to only those patients with clinical history or examination concerning sleep disordered breathing. We examined the prevalence and severity of OSA in all patients that were considered for bariatric surgery. We hypothesized that, by utilizing preoperative questionnaires (regarding sleepiness and OSA respiratory symptoms) in combination with menopausal status and BMI data, we would be able to predict which subjects did not have sleep apnea without the use of polysomnography. In addition, we hypothesized that we would be able to predict which subjects had severe OSA (apnea-hypopnea index (AHI) > 30).

METHODS

Three hundred forty-two consecutive subjects, evaluated for bariatric surgery from November 1, 2005 to January 31, 2007 underwent overnight polysomnography and completed questionnaires regarding sleepiness, menopausal status, and respiratory symptoms related to OSA. Apneas and hypopneas were classified as follows: mild apnea 5 ≤ AHI ≤ 15, moderate apnea 15 < AHI ≤ 30, and severe apnea AHI > 30.

RESULTS

The overall sample prevalence of OSA was 77.2%. Of these, 30.7% had mild OSA; 19.3% had moderate OSA, and 27.2% had severe OSA. Among men, the prevalence of OSA was 93.6% and 73.5% among women. The mean AHI (events per hour) for men with OSA was 49.2 ± 35.5 and 26.3 ± 28.3 for women with OSA. Separate logistic regression models were developed for the following three outcomes: AHI ≥ 5 events per hour, AHI > 15 events per hour, and AHI > 30 events per hour. When predicting these three levels of OSA severity, the area under the curve (AUC) values were: 0.8, 0.72, and 0.8, respectively. The negative predictive value for the presence of sleep apnea (AHI ≥ 5) was 75% when using the most stringent possible cutoff for the prediction model.

CONCLUSIONS

The prevalence of OSA in all patients considered for bariatric surgery was greater than 77%, irrespective of OSA symptoms, gender, menopausal status, age, or BMI. The prediction model that we developed for the presence of OSA (AHI ≥ 5 events per hour) has excellent discriminative ability (evidenced by an AUC value of 0.8). However, the negative prediction values for the presence of OSA were too low to be clinically useful due to the high prevalence of OSA in this high-risk group. We demonstrated that, by utilizing even the most stringent possible cutoff values for the prediction model, OSA cannot be predicted with enough certainty. Therefore, we advocate routine PSG testing for all patients that are considered for bariatric surgery.

Effects of Hemicellulose and Lignin on Enzymatic Hydrolysis of Cellulose from Dairy Manure

This study focused on the effect of hemicellulose and lignin on enzymatic hydrolysis of dairy manure and hydrolysis process optimization to improve sugar yield. It was found that hemicellulose and lignin in dairy manure, similar to their role in other lignocellulosic material, were major resistive factors to enzymatic hydrolysis and that the removal of either of them, or for best performance, both of them, improved the enzymatic hydrolysis of manure cellulose. This result combined with scanning electron microscope (SEM) pictures further proved that the accessibility of cellulose to cellulase was the most important feature to the hydrolysis. Quantitatively, fed-batch enzymatic hydrolysis of fiber without lignin and hemicellulose had a high glucose yield of 52% with respect to the glucose concentration of 17 g/L at a total enzyme loading of 1300 FPU/L and reaction time of 160 h, which was better than corresponding batch enzymatic hydrolysis.

Validation of venous leg ulcer guidelines in the United States and United Kingdom

BACKGROUND

Venous leg ulcers account for 85% of all lower-extremity ulcers, with treatment costs of 3 billion dollars and loss of 2 million workdays per year. The purpose of this study was to validate the clinical efficacy and cost effectiveness of multidisciplinary guidelines for the diagnosis and treatment of venous leg ulcers.

METHODS

Eighty (40 retrospective, 40 prospective) patients from the United States and United Kingdom were enrolled.

RESULTS

United States patients were 6.5 times and United Kingdom 2 times more likely to heal if a guideline was followed (P <0.001). A significant decrease was noted in healing time for both the United States and United Kingdom (P <0.01), and the median cost decreased significantly when the guideline was followed (P <0.01).

CONCLUSIONS

Implementation of a guideline for diagnosis and treatment of venous leg ulcers resulted in improvement in diagnosis, decrease in healing time, and an increase in healing rates resulting in lower costs.

Use of coping strategies and breast cancer survival: results from the Black/White Cancer Survival Study

This analysis was designed to evaluate the association between coping strategies and breast cancer survival among Black and White women in a large population-based study. A total of 442 Black and 405 White US women diagnosed with invasive breast cancer during 1985-1986 and actively followed for survival through 1994 were administered a modified Folkman and Lazarus Ways of Coping questionnaire. Coping strategies were characterized via factor analyses of the responses. Hazard ratios associated with coping strategies were estimated using Cox proportional hazards models, with adjustment for age, race, tumor stage, study location, tumor hormone responsiveness, comorbidity, health insurance status, smoking, relative body weight, and alcohol consumption. Emotion-focused coping strategies were significantly associated with survival. Expression of emotion was associated with better survival (hazard ratio = 0.6; 95% confidence interval: 0.4, 0.9). When it was considered jointly with the presence or absence of perceived emotional support, women reporting low levels of both emotional expression and perceived emotional support experienced poorer survival than women reporting high levels of both (hazard ratio = 2.5; 95% confidence interval: 1.7, 3.7). Similar risk relations were evident for Blacks and Whites and for patients with early and late stage disease. These results suggest that the opportunity for emotional expression may help improve survival among patients with invasive breast cancer.

Air pollution and daily mortality in the Coachella Valley, California: a study of PM10 dominated by coarse particles

Many epidemiological studies provide evidence of an association between airborne particles, measured as PM10 (particulate matter less than 10 microm in diameter), and daily morbidity and mortality. Most of these studies have been conducted in urban areas where PM10 consists primarily of fine particles (<2.5 microm in diameter). Few studies have investigated impacts associated with coarse mode particles (>2.5 microm in diameter). We investigated associations between PM10 and daily mortality in the Coachella Valley, a desert resort and retirement area east of Los Angeles, where coarse particles of geologic origin typically comprise approximately 50-60% of PM10 and can exceed 90% during wind events. Our analysis utilized daily data on mortality from 1989 through 1992 as well as several pollutant and meteorological variables, including PM10, nitrates, sulfates, ozone, nitrogen dioxide, carbon monoxide, temperature, and relative humidity. Outcome variables included several measures of daily mortality, including all-cause, cardiovascular and respiratory mortality, and counts of deaths for those above age 50. Multivariate Poisson regression models were used to explain these health endpoints, controlling for temperature, humidity, day of the week, season, and time, using locally weighted smoothing techniques. The analysis indicated statistically significant associations between PM10 (2- or 3-day lags) and each measure of mortality. The results were robust to various model specifications, correction for autocorrelation and overdispersion, and analysis of influential observations. A 10 microg/m3 change in daily PM10 was associated with an approximately 1% increase in mortality, which is of similar magnitude to particle-associated impacts identified in urban areas. Thus, our findings provide evidence for a mortality effect of PM10 in an area where the particulate mass is dominated by coarse particles.

Comparison of the upper gastrointestinal safety of Arthrotec 75 and nabumetone in osteoarthritis patients at high risk for developing nonsteroidal anti-inflammatory drug-induced gastrointestinal ulcers

A 6-week, multicenter, double-masked, placebo-controlled, parallel-group study compared the upper gastrointestinal (UGI) safety of Arthrotec 75 (diclofenac sodium 75 mg-misoprostol 200 microg; G.D. Searle & Co., Skokie, Illinois) administered twice daily with that of nabumetone 1500 mg administered once daily in 1203 patients with symptomatic osteoarthritis (OA) of the hip or knee. All patients had a documented clinical history of endoscopically confirmed gastric, pyloric-channel, or duodenal ulcer or > or = 10 erosions in the stomach or duodenum. UGI endoscopy was performed at baseline and again at week 6 or early withdrawal. Treatment with Arthrotec 75 resulted in a significantly lower combined incidence of endoscopically confirmed gastric and duodenal ulcers compared with nabumetone (4% vs 11%), and its rate of endoscopically confirmed ulceration was equivalent to that of placebo. The incidence of gastric ulcers alone was also significantly lower with Arthrotec 75 than with nabumetone (1% vs 9%). The incidence of duodenal ulcer with Arthrotec 75 was not significantly different from that with nabumetone (4% vs 3%). Types of adverse events were similar for all treatment groups, with GI adverse events predominating. Arthrotec 75 was well tolerated by the majority of patients. The results of this study demonstrate that Arthrotec 75 has a superior UGI safety profile, causing significantly fewer UGI ulcers, in comparison with nabumetone in patients with symptomatic OA and a documented history of ulcers or > or = 10 erosions.

Air pollution and emergency room visits for asthma in Santa Clara County, California

During the winters of 1986-1987 through 1991-1992, rainfall throughout much of Northern California was subnormal, resulting in intermittent accumulation of air pollution, much of which was attributable to residential wood combustion (RWC). This investigation examined whether there was a relationship between ambient air pollution in Santa Clara County, California and emergency room visits for asthma during the winters of 1988-1989 through 1991-1992. Emergency room (ER) records from three acute-care hospitals were abstracted to compile daily visits for asthma and a control diagnosis (gastroenteritis) for 3-month periods during each winter. Air monitoring data included daily coefficient of haze (COH) and every-other-day particulate matter with aerodynamic diameter equal to or less than 10 microns (PM10, 24-hr average), as well as hourly nitrogen dioxide and ozone concentrations. Daily COH measurements were used to predict values for missing days of PM10 to develop a complete PM10 time series. Daily data were also obtained for temperature, precipitation, and relative humidity. In time-series analyses using Poisson regression, consistent relationships were found between ER visits for asthma and PM10. Same-day nitrogen dioxide concentrations were also associated with asthma ER visits, while ozone was not. Because there was a significant interaction between PM10 and minimum temperature in this data set, estimates of relative risks (RRs) for PM10-associated asthma ER visits were temperature-dependent. A 60 micrograms/m3 change in PM10 (2-day lag) corresponded to RRs of 1.43 (95% CI = 1.18-1.69) at 20 degrees F, representing the low end of the temperature distribution, 1.27 (95% CI = 1.13-1.42) at 30 degrees F, and 1.11 (95% CI = 1.03-1.19) at 41 degrees F, the mean of the observed minimum temperature. ER visits for gastroenteritis were not significantly associated with any pollutant variable. Several sensitivity analyses, including the use of robust regressions and of nonparametric methods for fitting time trends and temperature effects in the data, supported these findings. These results demonstrate an association between ambient wintertime PM10 and exacerbations of asthma in an area where one of the principal sources of PM10 is RWC.

The capsular warning syndrome: pathogenesis and clinical features

Transient ischemic attacks (TIAs) are not homogeneous and may consist of subsets with mechanisms as varied as their stroke counterparts. We describe a form of TIA in 50 patients where crescendo episodes of ischemia were restricted to the region of the internal capsule, usually causing symptoms affecting face, arm, and leg. These patients composed 4.5% of a consecutive series of patients admitted with TIAs over a 15-year period and 33% of all TIAs classified as subcortical. We believe that the ischemia was most often due to hemodynamic phenomena in diseases, single, small penetrating vessels. When cerebral infarction developed, it was usually lacunar and involved a single penetrating vessel, although occasionally striatocapsular or anterior choroidal artery territory infarction occurred. There was no evidence of artery-to-artery or heart-to-artery embolism. Resistance to various forms of therapy, including hemodiluting, anticoagulant, and thrombolytic agents, was common. Because of dramatic and easily recognizable clinical presentation, apparent specific pathophysiologic mechanism, and the development of early capsular stroke in a high proportion of cases (42%), we have termed this the "capsular warning syndrome."

Development and validation of the PCQ: a questionnaire to measure the psychological consequences of screening mammography

We have developed a reliable and valid questionnaire to measure the psychological consequences of screening mammography. The questionnaire measures the effect of screening on an individual's functioning on emotional, social, and physical life domains. Content validity was ensured by extensive review of the relevant literature, discussion with professionals and interviews with attenders at a pilot Breast X-ray Screening Program in Melbourne, Australia. Discriminant validity was assessed by having expert judges sort items into dimensions which they appeared to be measuring. Acceptable levels of concordance (above 80%) with a priori classifications were found. Concurrent validity was demonstrated by comparison of subscale scores of 53 attenders at the Breast X-ray Program with an independent interview assessment of dysfunction on each of the emotional, social and physical dimensions. There was over 79% agreement between interview scores and questionnaire scores for each dimension. Construct validity was confirmed by showing that subscale scores varied in predicted ways. For women who were recalled for further investigation, scores on each subscale measuring negative consequences, were higher at the recall clinic than at screening clinic (emotional: t = -7.28; df = 70; P less than 0.001; physical: t = -2.53; df = 70; P = 0.014; social: t = -2.49; df = 70; P = 0.015). The internal consistency of all subscales was found to be acceptable. This questionnaire is potentially useful for assessing the psychological consequences of the screening process and should have wide application.

A review of cost-effectiveness analyses

A large number of cost-effectiveness analyses has been published over the last 16 years. Cost-effectiveness ratios (costs per year of life gained or quality adjusted year of life gained) derived through cost-effectiveness analysis can be used to compare the efficiency of different health-care programmes, although such comparisons should be made cautiously because of the uncertainties associated with many estimates of cost and effectiveness. Considering cardiovascular disease control programmes, for example, some preventive strategies, such as advice to quit smoking, or exercise programmes, are more cost-effective than antihypertensive treatment or coronary artery bypass grafting. However, cholestyramine therapy for prevention of coronary heart disease is less cost-effective than either of these treatments, and there are marked variations in the cost-effectiveness of many interventions, with factors such as the age group treated, frequency of treatment and level of parameters such as diastolic blood pressure, playing a role. Cancer control programmes are also considered in this paper. Cost-effectiveness analysis can be useful for assessing the relative costs and effectiveness of different programmes, but all relevant factors for policy-making and resource allocation can rarely be incorporated in a single analysis.

An approach to organ salvage from non-heartbeating cadaver donors under existing legal and ethical requirements for transplantation

Effective utilization of nonheartbeating cadaver donor organs is limited by the time required to obtain the necessary family consent prior to organ retrieval (a delay of at least 4-6 hr); this exceeds by far the maximum tolerance of kidneys to warm ischemia. Measures that could theoretically permit use of such organs include: (1) rapid in situ flush cooling; (2) continued in situ kidney cooling until permission for donation is secured; and (3) cell-membrane stabilization of vital organs, with only minimal invasion of the donor body. These measures were tested experimentally in dogs. Hemorrhagic shock was produced in mongrel dogs. One hour after cessation of heartbeat, a rapid perfusion tube was placed into the femoral artery; it was advanced, and its balloon was inflated in the aorta above the renal vessels. The kidneys were then flushed in situ with 1000 cc of cold preservation solution containing a calmodulin inhibitor, trifluoperazine. Two other catheters were inserted percutaneously into the peritoneal cavity for continuous intraperitoneal cold perfusion. Core temperatures of 4 degrees C were maintained in situ in the kidneys for 5 hr. Six hours after cardiac arrest, the kidneys were removed and preserved ex vivo at 4 degrees C for 24 hr, and were then transplanted into their respective hosts (n = 11), where they sustained life uneventfully. This method requires a 2-inch incision in the groin of the prospective donor, and two small stab wounds of the abdomen; i.e., semi-invasive procedures which are commonly performed in emergency rooms. The perfused body could then be released to the family if donation is denied. The recently documented increased willingness of the public to donate organs when the termination of life support is not an issue, and court decisions that have authorized the performance of nondeforming diagnostic procedures in cadavers without consent, suggest that the salvage of transplantable semi-invasive procedures described in this study may be useful in helping to alleviate the current shortage of transplantable organs. This technique can provide the time needed for families to consider the option of organ donation from nonheartbeating cadaver donors in an unhurried and unpressured manner, while preserving the viability of vital organs during the decision-making process.