Diffusiophoretic Transport of Charged Colloids in Ionic Surfactant Gradients Entirely below versus Entirely above the Critical Micelle Concentration

When placed in an ionic surfactant gradient, charged colloids will undergo diffusiophoresis at a velocity, uDP = MDP∇ ln S, where MDP is the diffusiophoretic mobility and S is the surfactant concentration. The diffusiophoretic mobility depends in part on the charges and diffusivities of the surfactants and their counterions. Since micellization decreases surfactant diffusivity and alters charge distributions in a surfactant solution, MDP of charged colloids in ionic surfactant gradients may differ significantly when surfactant concentrations are above or below the critical micelle concentration (CMC). The role of micelles in driving diffusiophoresis is unclear, and a previously published model that accounts for micellization suggests the possibility of a change in the sign of MDP above the CMC [Warren, P. B.; . Soft Matter 2019, 15, 278-288]. In the current study, microfluidic channels were used to measure the transport of negatively charged polystyrene colloids in sodium dodecyl sulfate (SDS) surfactant gradients established at SDS concentrations that are either fully above or fully below the CMC. Interpretation of diffusiophoresis was aided by measurements of the colloid electrophoretic mobility as a function of SDS concentration. A numerical transport model incorporating the prior diffusiophoretic mobility model for ionic surfactant gradients was implemented to elucidate signatures of positive and negative diffusiophoretic mobilities and compare with experiments. The theoretically predicted sign of the diffusiophoretic mobility below the CMC was determined to be particularly sensitive to uncertainty in colloid and surfactant properties, while above the CMC, the mobility was consistently predicted to be positive in the SDS concentration range considered in the experiments conducted here. In contrast, experiments only showed signatures of a negative diffusiophoretic mobility for these negatively charged colloids with no change of sign. Colloid diffusiophoretic transport measured in micellar solutions was more extensive than that below the CMC with the same ∇ ln S.

The recalibration and redevelopment of a model to calculate patients' probability of completing a colonoscopy following an abnormal fecal test

OBJECTIVES

Fecal immunochemical testing (FIT) is an effective screening tool for colorectal cancer. If an FIT is abnormal, a follow-up colonoscopy is necessary to remove polyps or find cancers. We sought to develop a usable risk prediction model to identify patients unlikely to complete a colonoscopy following an abnormal FIT test.

METHODS

We recalibrated and then redeveloped a prediction model in federally qualified health centers (FQHCs), using a retrospective cohort of patients aged 50-75 with an abnormal FIT test and clinical data. Logistic and Cox regressions were used to recalibrate and then redevelop the model.

RESULTS

The initial risk model used data from eight FQHCs (26 clinics) including 1723 patients. When we applied the model to a single large FQHC (34 clinics, 884 eligible patients), the model did not recalibrate successfully (c-statistic dropped more than 0.05, from 0.66 to 0.61). The model was redeveloped in the same FQHC in a cohort of 1401 patients with a c-statistic of 0.65.

CONCLUSIONS

The original model developed in a group of FQHCs did not adequately recalibrate in the single large FQHC. Health system, patient characteristics or data differences may have led to the inability to recalibrate the model. However, the redeveloped model provides an adequate model for the single FQHC.

The use of individual and multilevel data in the development of a risk prediction model to predict patients' likelihood of completing colorectal cancer screening

Promotion of colorectal cancer (CRC) screening can be expensive and unnecessary for many patients. The use of predictive analytics promises to help health systems target the right services to the right patients at the right time while improving population health. Multilevel data at the interpersonal, organizational, community, and policy levels, is rarely considered in clinical decision making but may be used to improve CRC screening risk prediction. We compared the effectiveness of a CRC screening risk prediction model that uses multilevel data with a more conventional model that uses only individual patient data. We used a retrospective cohort to ascertain the one-year occurrence of CRC screening. The cohort was determined from a Health Maintenance Organization, in Oregon. Eligible patients were 50-75 years old, health plan members for at least one year before their birthday in 2018 and were due for screening. We created a risk model using logistic regression first with data available in the electronic health record (EHR), and then added multilevel data. In a cohort of 59,249 patients, 36.1% completed CRC screening. The individual level model included 14 demographic, clinical and encounter based characteristics, had a bootstrap-corrected C-statistic of 0.722 and sufficient calibration. The multilevel model added 9 variables from clinical setting and community characteristics, and the bootstrap-corrected C-statistic remained the same with continued sufficient calibration. The predictive power of the CRC screening model did not improve after adding multilevel data. Our findings suggest that multilevel data added no improvement to the prediction of the likelihood of CRC screening.

A Molecular Thermodynamic Model of Coacervation in Solutions of Polycations and Oppositely Charged Micelles

To guide the rational design of personal care formulations, we formulate a molecular thermodynamic model that predicts coacervation from cationic polymers and mixed micelles containing neutral and anionic surfactants and added salt. These coacervates, which form as a result of dilution of conditioning shampoos during use, deposit conditioning agents and other actives to the scalp or skin and also provide lubrication benefits. Our model accounts for mixing entropy, hydrophobic interactions of polycation with water, free energies of bindings of oppositely charged groups to micelles and polycations, and electrostatic interactions that capture connectivity of charged groups on the polycation chain and the micelle. The model outputs are the compositions of surfactants, polycation, salt, and water in the coacervate and in its coexisting dilute phase, along with the binding fractions and coacervate volume fraction. We study the effects of overall composition (of surfactant, polycation, and added salt), charge fractions on micelles and polycations, and binding free energies on the phase diagram of coacervates. Then, we perform coacervation experiments for three systems: sodium dodecyl sulfate (SDS)-JR30M, sodium methyl cocoyl taurate (Taurate)-JR30M, and sodium lauryl alaninate (Alaninate)-JR30M, where JR30M is a cationic derivative of hydroxyethylcellulose (cat-HEC), and rationalize their coacervation data using our model. For comparison with experiment, we also develop a parametrization scheme to obtain the requisite binding energies and Flory-Huggins χ parameter. We find that our model predictions agree reasonably well with the experimental data, and that the sulfate-free surfactants of Taurate and Alaninate display much larger 2-phase regions compared to SDS with JR30M.

Cardiac events following JYNNEOS vaccination for prevention of Mpox

The incidence of cardiac adverse events following JYNNEOS vaccination for prevention of mpox is unknown, however the Advisory Committee on Immunization Practices states that people with underlying cardiac risk factors should be counseled about the theoretical risk for myopericarditis following vaccination. We conducted a retrospective cohort study of 2,126 patients who were vaccinated with at least 1 dose of JYNNEOS vaccine and searched the Kaiser Permanente Northwest databases, including the electronic health record, to evaluate for cardiac adverse events of special interest (AESI). After physician adjudication, there were 10 confirmed cardiac AESI for an incidence of 3.1 per 1000 doses (exact 95% CI, 1.5 to 5.7), however none of these events could be directly attributed to vaccination. This retrospective cohort study of JYNNEOS vaccination for prevention of mpox identified 10 cardiac events that all had alternative explanations; and no hospitalizations or serious adverse outcomes were attributed to vaccination.

Enhanced piroctone olamine retention from shampoo for superior anti-dandruff efficacy

BACKGROUND

Dandruff is a pervasive chronic condition which negatively impacts quality of life. Effective treatment requires efficient delivery of scalp benefit agents that control commensal scalp Malassezia levels. Delivery of benefit agents from shampoos requires balancing many technical parameters to achieve the desired outcome without sacrificing secondary parameters, such as cosmetic attributes.

AIM

To develop formulation technologies that increase the shampoo delivery efficiency of the scalp benefit agent piroctone olamine (PO). Increased delivery should result in increased anti-dandruff efficacy.

METHODS

Micellar Stability and Association parameters were quantified via dynamic surface tension and nuclear magnetic resonance (NMR) diffusion parameters, respectively. PO delivery has been assessed in vivo both on the scalp surface and follicular infindibula using extraction procedures and analytical analysis. Clinical anti-dandruff efficacy was assessed for an advanced delivery technology prototype in comparison to standard delivery technology.

RESULTS

Shampoo prototypes have been developed that increase the delivery efficiency of PO. Both surfactant and polymer coacervate-based approaches have been developed. Decreased micellar stability results in weaker association between PO and micelles, resulting in more efficient PO retention on the scalp surface and delivery to the infundibula. Increased charge density of cationic polymers optimizes coacervation enabling improved PO delivery as well. Increased PO delivery has been shown clinically to result in higher anti-dandruff efficacy as measured by both visible flakes and underlying biomarkers.

CONCLUSION

Increased efficiency PO delivery shampoos have been developed by optimization of both surfactant and coacervate parameters. The increased deposition efficiency results in significantly more products with significantly greater anti-dandruff efficacy.

Risk of Myopericarditis following COVID ‐19 mRNA vaccination in a Large Integrated Health System: A Comparison of Completeness and Timeliness of Two Methods

Purpose

How completely do hospital discharge diagnoses identify cases of myopericarditis after an mRNA vaccine?

Methods

We assembled a cohort 12–39 year‐old patients, insured by Kaiser Permanente Northwest, who received at least one dose of an mRNA vaccine (Pfizer‐BioNTech or Moderna) between December 2020 and October 2021. We followed them for up to 30 days after their second dose of an mRNA vaccine to identify encounters for myocarditis, pericarditis or myopericarditis. We compared two identification methods: A method that searched all encounter diagnoses using a brief text description (e.g., ICD‐10‐CM code I40.9 is defined as ‘acute myocarditis, unspecified’). We searched the text description of all inpatient or outpatient encounter diagnoses (in any position) for “myocarditis” or “pericarditis.” The other method was developed by the Centers for Disease Control and Prevention's Vaccine Safety Datalink (VSD), which searched for emergency department visits or hospitalizations with a select set of discharge ICD‐10‐CM diagnosis codes. For both methods, two physicians independently reviewed the identified patient records and classified them as confirmed, probable or not cases using the CDC's case definition.

Results

The encounter methodology identified 14 distinct patients who met the confirmed or probable CDC case definition for acute myocarditis or pericarditis with an onset within 21 days of receipt of COVID‐19 vaccination. When we extended the search for relevant diagnoses to 30 days since vaccination, we identified two additional patients (for a total of 16 patients) who met the case definition for acute myocarditis or pericarditis, but those patients had been misdiagnosed at the time of their original presentation. Three of these patients had an ICD‐10‐CM code of I51.4 “Myocarditis, Unspecified;” that code was omitted by the VSD algorithm (in the late fall of 2021). The VSD methodology identified 11 patients who met the CDC case definition for acute myocarditis or pericarditis. Seven (64%) of the 11 patients had initial care for myopericarditis outside of a KPNW facility and their diagnosis could not be ascertained by the VSD methodology until claims were submitted (median delay of 33 days; range of 12–195 days). Among those who received a second dose of vaccine (n = 146 785), we estimated a risk as 95.4 cases of myopericarditis per million second doses administered (95% CI, 52.1–160.0).

Conclusion

We identified additional valid cases of myopericarditis following an mRNA vaccination that would be missed by the VSD's search algorithm, which depends on select hospital discharge diagnosis codes. The true incidence of myopericarditis is markedly higher than the incidence reported to US advisory committees in the fall of 2021. The VSD should validate its search algorithm to improve its sensitivity for myopericarditis.

Comparison of a Kidney Replacement Therapy Risk Score Developed in Kaiser Permanente Northwest vs Estimated Glomerular Filtration Rate in Advanced Chronic Kidney Disease Using Decision Curve Analysis

INTRODUCTION

Use of kidney replacement therapy (KRT) prediction models for guiding arteriovenous fistula (AVF) referrals in advanced chronic kidney disease (CKD) is unknown. We aimed to compare a hypothetical approach using a KRT prediction model developed in Kaiser Permanente Northwest to estimated glomerular filtration rate (eGFR) for AVF referrals.

METHODS

Our retrospective cohort consisted of patients with stage G4 CKD in Kaiser Permanente Northwest followed by nephrology. Two-year KRT risk was calculated at each nephrology visit up to 2 years from entrance into cohort based on a previously published model. We calculated sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) based on several 2-year KRT risk and eGFR cutoffs for outcome of hemodialysis at 18 months. We compared an approach of AVF referral using 2-year KRT risk and eGFR cutoffs using decision curve analysis.

RESULTS

Two-year KRT risk better discriminated progression to hemodialysis compared to eGFR < 15 mL/min (AUC 0.60 vs 0.69 at 2-year KRT risk > 20% and 0.69 at 2-year KRT risk > 40%, p = 0.003 and 0.006, respectively) but not to eGFR of 20 mL/min (AUC 0.64, p = 0.16 and 0.19, respectively). Decision curve analysis showed that AVF referral guided by 2-year KRT risk score resulted in higher net benefit compared to eGFR at low thresholds for referral.

CONCLUSION

In stage G4 CKD, a 2-year KRT risk model better predicted progression to KRT at 18 months compared to an eGFR of 15 mL/min but not to 20 mL/min and may improve timely referral for AVF placement in patients at lower thresholds for referral.

Precision Patient Navigation to Improve Rates of Follow-up Colonoscopy, An Individual Randomized Effectiveness Trial

BACKGROUND

Colorectal cancer screening by annual fecal immunochemical test (FIT) with follow-up on abnormal results is a cost-effective strategy to reduce colorectal cancer incidence and mortality. Unfortunately, many patients with abnormal results do not complete a follow-up colonoscopy. We tested whether navigation targeted to patients who are unlikely to complete the procedure may improve adherence and long-term outcomes.

METHODS

Study participants were patients at a large, integrated health system (Kaiser Permanente Northwest) who were ages 50 to 75 and were due for a follow-up colonoscopy after a recent abnormal FIT result. Probability of adherence to follow-up was estimated at baseline using a predictive risk model. Patients whose probability was 70% or lower were randomized to receive patient navigation or usual care, with randomization stratified by probability category (<50%, 50% < 60%, 60% < 65%, 65% ≤ 70%). We compared colonoscopy completion within 6 months between the navigation and usual care groups using Cox proportional hazards regression.

RESULTS

Participants (n = 415; 200 assigned to patient navigation, 215 to usual care) had a mean age of 62 years, 54% were female, and 87% were non-Hispanic white. By 6 months, 76% of the patient navigation group had completed a colonoscopy, compared with 65% of the usual care group (HR = 1.35; 95% confidence interval, 1.07-1.72; log-rank P value = 0.027).

CONCLUSIONS

In this randomized trial, patient navigation led to improvements in follow-up colonoscopy adherence.

IMPACT

More research is needed to assess the value of precision-directed navigation programs.

Physician adjudication of angioedema diagnosis codes in a population of patients with heart failure prescribed angiotensin-converting enzyme inhibitor therapy

PURPOSE

Our objective was to calculate the positive predictive value (PPV) of the ICD-9 diagnosis code for angioedema when physicians adjudicate the events by electronic health record review. Our secondary objective was to evaluate the inter-rater reliability of physician adjudication.

METHODS

Patients from the Cardiovascular Research Network previously diagnosed with heart failure who were started on angiotensin-converting enzyme inhibitors (ACEI) during the study period (July 1, 2006 through September 30, 2015) were included. A team of two physicians per participating site adjudicated possible events using electronic health records for all patients coded for angioedema for a total of five sites. The PPV was calculated as the number of physician-adjudicated cases divided by all cases with the diagnosis code of angioedema (ICD-9-CM code 995.1) meeting the inclusion criteria. The inter-rater reliability of physician teams, or kappa statistic, was also calculated.

RESULTS

There were 38 061 adults with heart failure initiating ACEI in the study (21 489 patient-years). Of 114 coded events that were adjudicated by physicians, 98 angioedema events were confirmed for a PPV of 86% (95% CI: 80%, 92%). The kappa statistic based on physician inter-rater reliability was 0.65 (95% CI: 0.47, 0.82).

CONCLUSIONS

ICD-9 diagnosis code of 995.1 (angioneurotic edema, not elsewhere classified) is highly predictive of angioedema in adults with heart failure exposed to ACEI.

Abstract PO-270: The validation and redevelopment of a risk prediction model identifying patients unlikely to complete a colonoscopy following an abnormal FIT test in community clinics

Background: Fecal testing (FIT) is an effective screening tool for colorectal cancer. If a FIT is abnormal, a follow-up colonoscopy is necessary to remove polyps or find cancers. Predicting which patients may be at risk for failing to follow-up on an abnormal fecal test could help identify patients in need of early interventions aimed at completing a colonoscopy. Using predictive analytics to determine who is unlikely to follow-up will allow health systems to tailor interventions and outreach.

Understanding the application of predictive analytics across health systems is imperative to providing appropriate care to distinct patient populations. Early interventions could decrease the disease burden if colorectal cancer is found at earlier stages. Methods: We compare two models created in two different settings. The models were created from data from FQHC’s and Logistic and Cox regressions to validate and redevelop a risk prediction model among a retrospective dataset of patients with abnormal FIT results. Results: The initial FQHC risk model included eight variables including race, clinic system, prior no-shows, insurance, prior flu shots, age, indication of anti-coagulation use, and income inequality. However, the model did not validate in a large similar health system in the Pacific Northwest. Risk factors for colonoscopy varied by county, clinics, regions, and patient populations.

Inner and outer setting variables, like referral workflows and access to colonoscopy, contributed to the likelihood of a patient completing their screening. The second model retained most predictors except for anti-coagulation use, and included new predictors like language, homeless status, prior screenings, and a comorbidity index. Conclusions: Application of a risk model helps tailor interventions to help patients complete the continuum of screening for colorectal cancer. However, health systems differ, and precision medicine is best applied when risk is understood in context and interventions are tailored for specific populations predictors.

Citation Format: Amanda F. Petrik, Eric S. Johnson, Matthew Slaughter, Andreea Rawlings, Michael Leo, Jamie Thompson, Ricardo Jimenez, Gloria D. Coronado. The validation and redevelopment of a risk prediction model identifying patients unlikely to complete a colonoscopy following an abnormal FIT test in community clinics [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-270.

Development of a multivariable prediction model to identify patients unlikely to complete a colonoscopy following an abnormal FIT test in community clinics

Background

Colorectal cancer (CRC) is the 3rd leading cancer killer among men and women in the US. The Strategies and Opportunities to STOP Colon Cancer in Priority Populations (STOP CRC) project aimed to increase CRC screening among patients in Federally Qualified Health Centers (FQHCs) through a mailed fecal immunochemical test (FIT) outreach program. However, rates of completion of the follow-up colonoscopy following an abnormal FIT remain low. We developed a multivariable prediction model using data available in the electronic health record to assess the probability of patients obtaining a colonoscopy following an abnormal FIT test.

Methods

To assess the probability of obtaining a colonoscopy, we used Cox regression to develop a risk prediction model among a retrospective cohort of patients with an abnormal FIT result.

Results

Of 1596 patients with an abnormal FIT result, 556 (34.8%) had a recorded colonoscopy within 6 months. The model shows an adequate separation of patients across risk levels for non-adherence to follow-up colonoscopy (bootstrap-corrected C-statistic > 0.63). The refined model included 8 variables: age, race, insurance, GINI income inequality, long-term anticoagulant use, receipt of a flu vaccine in the past year, frequency of missed clinic appointments, and clinic site. The probability of obtaining a follow-up colonoscopy within 6 months varied across quintiles; patients in the lowest quintile had an estimated 18% chance, whereas patients in the top quintile had a greater than 55% chance of obtaining a follow-up colonoscopy.

Conclusions

Knowing who is unlikely to follow-up on an abnormal FIT test could help identify patients who need an early intervention aimed at completing a follow-up colonoscopy.

Trial registration

This trial was registered at ClinicalTrials.gov (NCT01742065) on December 5, 2012. The protocol is available.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-020-05883-2.

Predicted risk of renal replacement therapy at arteriovenous fistula referral in chronic kidney disease

BACKGROUND AND OBJECTIVES

Optimal timing of arteriovenous fistula placement in chronic kidney disease remains difficult and contributes to high central venous catheter use at initial hemodialysis. We tested whether a prediction model for progression to renal replacement therapy developed at Kaiser Permanente Northwest may help guide decisions about timing of referral for arteriovenous fistula placement.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

A total of 205 chronic kidney disease stage 4 patients followed by nephrology referred for arteriovenous fistula placement were followed for up to 2 years. Patients were censored if they died or discontinued Kaiser Permanente Northwest coverage. Survival analyses were performed for overall progression to renal replacement therapy divided by quartiles based on 2-year risk for renal replacement therapy and estimated glomerular filtrate rate at time of referral.

RESULTS

By 2 years, 60% progressed to renal replacement therapy and 11% had died. 80% in the highest risk versus 36% in the lowest risk quartile progressed to renal replacement therapy (predicted risk 84% vs 17%). 75% in the lowest estimated glomerular filtrate rate versus 56% in the highest estimated glomerular filtrate rate quartile progressed to renal replacement therapy (mean estimated glomerular filtrate rate 13 mL/min vs 21 mL/min). The hazard ratio was significantly higher for each consecutive higher renal replacement therapy quartile risk while for estimated glomerular filtrate rate, the hazard ratio was only significantly higher for the lowest compared to the highest quartile. The extreme quartile risk ratio was higher for 2-year risk for renal replacement therapy compared to estimated glomerular filtrate rate (4.0 vs 2.4).

CONCLUSION

In patients with chronic kidney disease stage 4 referred for arteriovenous fistula placement, 2-year renal replacement therapy risk better discriminated progression to renal replacement therapy compared to estimated glomerular filtrate rate at time of referral.

Patient randomized trial of a targeted navigation program to improve rates of follow-up colonoscopy in community health centers

BACKGROUND

Colorectal cancer (CRC) screening by annual fecal immunochemical test (FIT) is an accessible and cost-effective strategy to lower CRC incidence and mortality. However, this mode of screening depends on follow-up colonoscopy after a positive FIT result. Unfortunately, nearly one-half of FIT-positive patients fail to complete this essential screening component. Patient navigation may improve follow-up colonoscopy adherence. To deliver patient navigation cost-effectively, health centers could target navigation to patients who are unlikely to complete the procedure on their own.

OBJECTIVES

The Predicting and Addressing Colonoscopy Non-adherence in Community Settings (PRECISE) clinical trial will validate a risk model of follow-up colonoscopy adherence and test whether patient navigation raises rates of colonoscopy adherence overall and among patients in each probability stratum (low, moderate, and high probability of adherence without intervention).

METHODS

PRECISE is a collaboration with a large community health center whose patient population is 37% Latino. Eligible patients will be aged 50-75, have an abnormal FIT result in the past month, and be due for a follow-up colonoscopy. Patients will be randomized to patient navigation or usual care. Primary outcomes will be colonoscopy completion within one year of a positive FIT result, cost, and cost-effectiveness. Secondary outcomes will include time to colonoscopy receipt, adequacy of bowel prep, and communication of results to primary care providers. Primary and secondary outcomes will be reported overall and by probability stratum.

DISCUSSION

This innovative clinical trial will test the effectiveness and financial feasibility of using a precision health intervention to improve CRC screening completion in community health centers.

TRIAL REGISTRATION

National Clinical Trial (NCT) Identifier: NCT03925883.

A randomized, pragmatic, pharmacist-led intervention reduced opioids following orthopedic surgery

OBJECTIVES

To determine whether a pharmacist-led, patient-directed intervention can reduce opioid use following total hip arthroplasty (THA) or total knee arthroplasty (TKA).

STUDY DESIGN

Randomized trial.

METHODS

Patients scheduled to undergo THA or TKA (during 2015 and 2016) were randomized to usual care or intervention. We ranked patients according to predicted risk of persistent opioid use and selected the top 60% for inclusion (n = 561); all contributed to the analysis. Intervention patients were mailed materials 2 weeks before and after surgery, plus they received telephone intervention from specially trained pharmacists if they filled opioid prescriptions in the 28 to 90 days following surgery. Our primary outcome was the dispensed morphine equivalents (DME) in the 90 days following surgery, modeled using a natural log transformation.

RESULTS

A total of 561 patients were randomized (286 usual care, 118 THA and 168 TKA; 275 intervention, 107 THA and 168 TKA); the mean age was 66 years, and 60% were female. Overall, we found no meaningful reduction in DME for intervention versus usual care (geometric mean ratio, 0.92 [95% CI, 0.69-1.21]). However, there was effect modification by whether the patient had TKA or THA (interaction P <.01). Those undergoing THA in the intervention group used significantly less DME than did those undergoing THA in the usual care group (geometric mean ratio, 0.52 [95% CI, 0.33-0.82]).

CONCLUSIONS

Our pharmacist-led, patient-directed intervention to reduce opioid use demonstrated a reduction in opioid dispensings in the 90 days following THA but not TKA.

Excess lung cancer occurrence in poultry plants. Occupational risk factors: Findings for oncogenic viruses exposure and other occupational exposures

Certain viruses naturally infect and cause cancer in chickens and turkeys. Humans are widely exposed. The viruses cause cancer in primates, and transform human cells in vitro, but it is not known if they cause cancer in humans, mainly because of the lack of epidemiologic evidence. We conducted cohort mortality studies of workers in poultry slaughtering/processing plants across the United States, because they have the highest human exposures. An excess of lung cancer and other deaths was recorded in the poultry workers. Here, we report on a case-cohort study of the lung cancer deaths nested within these cohorts, that was conducted to provide epidemiologic evidence linking these viruses with human cancer occurrence, while adjusting for possible confounders, including workplace chemical carcinogens. We obtained interviews for 339 lung cancer deaths and 457 controls, selected from our combined cohorts of 30,411 poultry plant workers and 16,405 non-poultry workers, belonging to United Food & Commercial Workers unions. Data was analyzed by both logistic regression and Cox regression, adjusting for smoking and other confounders. Lung cancer risk was independently associated with tasks or work areas indicative of exposure to both poultry oncogenic viruses and to workplace chemical carcinogens. The study provides an incremental piece of evidence (epidemiologic), indirectly linking the oncogenic viruses of poultry with the occurrence of cancer in humans, and thus may have public health implications, but the limitations highlighted must be considered. Confirmatory studies, particularly molecular studies providing definitive proof of poultry oncogenic retrovirus integration in human DNA are needed, before the findings observed in this study can be put into proper perspective.

Comparative Effectiveness of Usual Care With or Without Chiropractic Care in Patients with Recurrent Musculoskeletal Back and Neck Pain

BACKGROUND

Chiropractic care is a popular alternative for back and neck pain, with efficacy comparable to usual care in randomized trials. However, the effectiveness of chiropractic care as delivered through conventional care settings remains largely unexplored.

OBJECTIVE

To evaluate the comparative effectiveness of usual care with or without chiropractic care for patients with chronic recurrent musculoskeletal back and neck pain.

STUDY DESIGN

Prospective cohort study using propensity score-matched controls.

PARTICIPANTS

Using retrospective electronic health record data, we developed a propensity score model predicting likelihood of chiropractic referral. Eligible patients with back or neck pain were then contacted upon referral for chiropractic care and enrolled in a prospective study. For each referred patient, two propensity score-matched non-referred patients were contacted and enrolled. We followed the participants prospectively for 6 months.

MAIN MEASURES

Main outcomes included pain severity, interference, and symptom bothersomeness. Secondary outcomes included expenditures for pain-related health care.

KEY RESULTS

Both groups' (N = 70 referred, 139 non-referred) pain scores improved significantly over the first 3 months, with less change between months 3 and 6. No significant between-group difference was observed. (severity - 0.10 (95% CI - 0.30, 0.10), interference - 0.07 (- 0.31, 0.16), bothersomeness - 0.1 (- 0.39, 0.19)). After controlling for variances in baseline costs, total costs during the 6-month post-enrollment follow-up were significantly higher on average in the non-referred versus referred group ($1996 [SD = 3874] vs $1086 [SD = 1212], p = .034). Adjusting for differences in age, gender, and Charlson comorbidity index attenuated this finding, which was no longer statistically significant (p = .072).

CONCLUSIONS

We found no statistically significant difference between the two groups in either patient-reported or economic outcomes. As clinical outcomes were similar, and the provision of chiropractic care did not increase costs, making chiropractic services available provided an additional viable option for patients who prefer this type of care, at no additional expense.

Association of Proteinuria with Central Venous Catheter Use at Initial Hemodialysis

CONTEXT

Central venous catheter (CVC) use is associated with increased mortality and complications in hemodialysis recipients. Although prevalent CVC use has decreased, incident use remains high.

OBJECTIVE

To examine characteristics associated with CVC use at initial dialysis, specifically looking at proteinuria as a predictor of interest.

DESIGN

Retrospective cohort of 918 hemodialysis recipients from Kaiser Permanente Northwest who started hemodialysis from January 1, 2004, to January 1, 2014.

MAIN OUTCOME MEASURES

Multivariable logistic regression was used to examine an association of proteinuria with the primary outcome of CVC use.

RESULTS

More than one-third (36%) of patients in our cohort started hemodialysis with an arteriovenous fistula, and 64% started with a CVC. Proteinuria was associated with starting hemodialysis with a CVC (likelihood ratio test, p < 0.001) after adjustment for age, peripheral vascular disease, congestive heart failure, diabetes, sex, race, and length of predialysis care. However, on pairwise comparison, only patients with midgrade proteinuria (0.5-3.5 g) had lower odds of starting hemodialysis with a CVC (odds ratio = 0.39, 95% confidence interval = 0.24-0.65).

CONCLUSION

Proteinuria was associated with use of CVC at initial hemodialysis. However, a graded association did not exist, and only patients with midgrade proteinuria had significantly lower odds of CVC use. Our findings suggest that proteinuria is an explanatory finding for CVC use but may not have pragmatic value for decision making. Patients with lower levels of proteinuria may have a higher risk of starting dialysis with a CVC.

Predicting Hypertension Among Children With Incident Elevated Blood Pressure

OBJECTIVE

To develop a model to predict hypertension risk among children with incident elevated blood pressure (BP); to test the external validity of the model.

METHODS

A retrospective cohort study was conducted in 3 organizations: Kaiser Permanente Colorado was the model derivation site; HealthPartners of Minnesota and Kaiser Permanente Northern California served as external validation sites. During study years 2006 through 2012, all children aged 3 through 17 years with incident elevated BP in an outpatient setting were identified. The predictor variables were demographic and clinical characteristics collected during routine care. Cox proportional hazards regression was used to predict subsequent hypertension, and diagnostic statistics were used to assess model performance.

RESULTS

Among 5598 subjects at the derivation site with incident elevated BP, 160 (2.9%) developed hypertension during the study period. Eight characteristics were used to predict hypertension risk: age, sex, race, BP preceding incident elevated BP, body mass index percentile, systolic BP percentile, diastolic BP percentile, and clinical setting of the incident elevated BP. At the derivation site, the model discriminated well between those at higher versus lower risk of hypertension (c-statistic = 0.77). At external validation sites, the observed risk of hypertension was higher than the predicted risk, and the model showed poor discrimination (c-statistic ranged from 0.64 to 0.67).

CONCLUSIONS

Among children with incident elevated BP, a risk model demonstrated good internal validity with respect to predicting subsequent hypertension. However, the risk model did not perform well at 2 external validation sites, which might limit transportability to other settings.

The feasibility of matching on a propensity score for acupuncture in a prospective cohort study of patients with chronic pain

Background

Propensity scores are typically applied in retrospective cohort studies. We describe the feasibility of matching on a propensity score derived from a retrospective cohort and subsequently applied in a prospective cohort study of patients with chronic musculoskeletal pain before the start of acupuncture or usual care treatment and enrollment in a comparative effectiveness study that required patient reported pain outcomes.

Methods

We assembled a retrospective cohort study using data from 2010 to develop a propensity score for acupuncture versus usual care based on electronic healthcare record and administrative data (e.g., pharmacy) from an integrated health plan, Kaiser Permanente Northwest. The propensity score’s probabilities allowed us to match acupuncture-referred and non-referred patients prospectively in 2013-14 after a routine outpatient visit for pain. Among the matched patients, we collected patient-reported pain before treatment and during follow-up to assess the comparative effectiveness of acupuncture. We assessed balance in patient characteristics with the post-matching c-statistic and standardized differences.

Results

Based on the propensity score and other characteristics (e.g., patient-reported pain), we were able to match all 173 acupuncture-referred patients to 350 non-referred (usual care) patients. We observed a residual imbalance (based on the standardized differences) for some characteristics that contributed to the score; for example, age, -0.283, and the Charlson comorbidity score, -0.264, had the largest standardized differences. The overall balance of the propensity score appeared more favorable according to the post-matching c-statistic, 0.503.

Conclusion

The propensity score matching was feasible statistically and logistically and allowed approximate balance on patient characteristics, some of which will require adjustment in the comparative effectiveness regression model. By transporting propensity scores to new patients, healthcare systems with electronic health records can conduct comparative effectiveness cohort studies that require prospective data collection, such as patient-reported outcomes, while approximately balancing numerous patient characteristics that might confound the benefit of an intervention. The approach offers a new study design option.

Predicting 5-Year Risk of RRT in Stage 3 or 4 CKD: Development and External Validation

BACKGROUND AND OBJECTIVES

Only a minority of patients with CKD progress to renal failure. Despite the potential benefits of risk stratification in the CKD population, risk prediction models are not routinely used. Our objective was to develop and externally validate a clinically useful and pragmatic prediction model for the 5-year risk of progression to RRT in stage 3 or 4 CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used a retrospective cohort design. The development cohort consisted of 22,460 Kaiser Permanente Northwest members with stage 3 or 4 CKD (baseline 2002-2008). The validation cohort consisted of 16,553 Kaiser Permanente Colorado members with stage 3-4 CKD (baseline 2006-2008). The final model included eight predictors: age, sex, eGFR, hemoglobin, proteinuria/albuminuria, systolic BP, antihypertensive medication use, and diabetes and its complications.

RESULTS

In the Northwest and Colorado cohorts, there were 737 and 360 events, and observed 5-year Kaplan-Meier risks of 4.72% (95% confidence interval [95% CI], 4.38 to 5.06) and 2.57% (95% CI, 2.30 to 2.83), respectively. Our prediction model performed extremely well in the development cohort, with a c-statistic of 0.96, an R2 of 79.7%, and good calibration. We had similarly good performance in the external validation cohort, with a c-statistic of 0.95, R2 of 81.2%, and good calibration. In the external validation cohort, the observed risk was slightly lower than the predicted risk in the highest-risk quintile. Using the top quintile of predicted risk as a cutpoint gave a sensitivity of 92.2%.

CONCLUSIONS

We developed a pragmatic prediction model and risk score for predicting the 5-year RRT risk in stage 3 and 4 CKD. This model uses variables that are typically available in routine primary care settings, and can be used to help guide important decisions such as timing of referral to nephrology and fistula placement.

Predicting the Risk of Clostridium difficile Infection upon Admission: A Score to Identify Patients for Antimicrobial Stewardship Efforts

INTRODUCTION

Increasing morbidity and health care costs related to Clostridium difficile infection (CDI) have heightened interest in methods to identify patients who would most benefit from interventions to mitigate the likelihood of CDI.

OBJECTIVE

To develop a risk score that can be calculated upon hospital admission and used by antimicrobial stewards, including pharmacists and clinicians, to identify patients at risk for CDI who would benefit from enhanced antibiotic review and patient education.

METHODS

We assembled a cohort of Kaiser Permanente Northwest patients with a hospital admission from July 1, 2005, through December 30, 2012, and identified CDI in the six months following hospital admission. Using Cox regression, we constructed a score to identify patients at high risk for CDI on the basis of preadmission characteristics. We calculated and plotted the observed six-month CDI risk for each decile of predicted risk.

RESULTS

We identified 721 CDIs following 54,186 hospital admissions-a 6-month incidence of 13.3 CDIs/1000 patient admissions. Patients with the highest predicted risk of CDI had an observed incidence of 53 CDIs/1000 patient admissions. The score differentiated between patients who do and do not develop CDI, with values for the extended C-statistic of 0.75. Predicted risk for CDI agreed closely with observed risk.

CONCLUSION

Our risk score accurately predicted six-month risk for CDI using preadmission characteristics. Accurate predictions among the highest-risk patient subgroups allow for the identification of patients who could be targeted for and who would likely benefit from review of inpatient antibiotic use or enhanced educational efforts at the time of discharge planning.

Non-treatment of children with community health worker-diagnosed fast-breathing pneumonia in rural Malawi: exploratory subanalysis of a prospective cohort study

BACKGROUND

Despite recent progress, pneumonia remains the largest infectious killer of children globally. This paper describes outcomes of not treating community-diagnosed fast-breathing pneumonia on patient recovery.

METHODS

We conducted an exploratory subanalysis of an observational prospective cohort study in Malawi. We recruited children (2-59 months) diagnosed by community health workers with fast-breathing pneumonia using WHO integrated community case management (iCCM) guidelines. Children were followed at days 5 and 14 with a clinical assessment of recovery. We conducted bivariate and multivariable logistic regression for the association between treatment of fast-breathing pneumonia and recovery, adjusting for potential confounders.

RESULTS

We followed up 847 children, of whom 78 (9%) had not been given antibiotics (non-treatment). Non-treatment cases had higher baseline rates of diarrhoea, non-severe hypoxaemia and fever. Non-recovery (persistence or worsening of symptoms) was 13% and 23% at day 5 in those who did receive and those who did not receive co-trimoxazole. Non-recovery, when defined as worsening of symptoms only, at day 5 was 7% in treatment and 10% in non-treatment cases. For both definitions, combined co-trimoxazole and lumefantrine-artemether (LA) treatment trended towards protection (adjusted OR (aOR) 0.28; 95% CI 0.12 to 0.68/aOR 0.29; 95% CI 0.08 to 1.01).

CONCLUSION

We found that children who did not receive co-trimoxazole treatment had worse clinical outcomes; malaria co-diagnosis and treatment also play a significant role in non-recovery. Further research into non-treatment of fast-breathing pneumonia, using a pragmatic approach with consideration for malaria co-diagnosis and HIV status is needed to guide refinement of community treatment algorithms in this region.

Community Blood Supply Model: Development of a New Model to Assess the Safety, Sufficiency, and Cost of the Blood Supply

Background. Through a combination of predonation donor screening and donated unit testing, the blood supply is safer than ever. However, as a result of increasingly stringent screening measures, one of the greatest threats may be an insufficient supply. The balance between safety and adequacy of the blood supply has not received enough attention. Study Design and Methods. The authors developed a model to allow for empirical investigation of the determinants of a safe and sufficient supply. The model is a cohort simulation of allogeneic whole-blood donation, with the population of presenting donors stratified into 8 age and gender groups because the probability of donor and donation deferral varies by these characteristics. Parameters are estimated from year 2000 Blood Centers of Pacific (BCP) data. The model includes cost parameters, which were estimated using BCP expenditure data. The main outcomes are the number of transfusable units of blood and the unit cost of procurement. Results. The model tracks the production of a supply of blood, highlighting the influence of demographic characteristics, predonation deferral, underweight collection of blood units, and associated costs. The authors sought to establish model validity by showing that modeled results closely mimic the outcomes and costs observed by blood bank administrators. Conclusion. The model was developed to evaluate blood safety and policy decisions; it can be used to assess the impact of predonation deferrals, such as expanded European travel deferral for variant Creutzfeldt-Jakob disease, or the impact of new testing strategies, such as nucleic acid testing for West Nile virus.

Long-Term Nonmalignant Disease Mortality in Subjects Exposed to Transmissible Agents Present in Animals Used for Food

OBJECTIVE

To study mortality from nonmalignant diseases in subjects with high exposure to transmissible agents present in animals used for food, and in their raw or inadequately cooked products.

METHODS

Mortality was compared in a cohort of meat handlers in slaughtering and processing plants with that of the U.S. general population.

RESULTS

Excess mortality was observed for conditions known to be associated with infections-these include, septicemia, chronic nephritis, diseases of the kidney and ureter, diseases of the pancreas, cirrhosis of the liver, acute and subacute endocarditis, acute rheumatic fever, functional diseases of the heart, aortic aneurysm, intracranial and intraspinous abscess, and meningitis. Excess mortality was also observed for ischemic heart disease and diabetes, conditions without an established infectious etiology, but which have been linked with infections.

CONCLUSIONS

If transmissible agents present in food animals and their raw products cause long-term diseases and mortality in humans, this study importantly points to the likely diseases, many of which are already known to be associated with infections. The excess mortality observed for ischemic heart disease and diabetes is consistent with existing evidence linking these conditions with infections, and gives rise to the novel hypothesis that microbial agents present in food animals and their products may be candidates for an infective role in the occurrence of these conditions, and therefore needs further investigation.

Comparative Effectiveness of Statin Therapy in Chronic Kidney Disease and Acute Myocardial Infarction: A Retrospective Cohort Study

BACKGROUND

Whether there is a kidney function threshold to statin effectiveness in patients with acute myocardial infarction is poorly understood. Our study sought to help fill this gap in clinical knowledge.

METHODS

We undertook a new-user cohort study of the effectiveness of statin therapy by level of estimated glomerular filtration rate (eGFR) in adults who were hospitalized for myocardial infarction between 2000 and 2008. Data came from the Cardiovascular Research Network. The primary clinical outcomes were 1-year all-cause mortality and cardiovascular hospitalizations, with adverse outcomes of myopathy and development of diabetes mellitus. We calculated incidence rates, the number needed to treat, and used Cox proportional hazards regression with propensity score matching and adjustment to control for confounding, with testing for variation of effect by level of kidney function.

RESULTS

Compared with statin non-initiators (n = 5583), statin initiators (n = 5597) had a lower propensity score-adjusted risk for death (hazard ratio 0.79; 95% confidence interval [CI], 0.71-0.88) and cardiovascular hospitalizations (hazard ratio 0.90; 95% CI, 0.82-1.00). We found little evidence of variation in effect by level of eGFR (P = .86 for death; P = .77 for cardiovascular hospitalization). Adverse outcomes were similar for statin initiators and statin non-initiators. The number needed to treat to prevent 1 additional death over 1 year of follow-up ranged from 15 (95% CI, 11-28) for eGFR <30 mL/min/1.73 m(2) requiring statin treatment over 2 years to prevent 1 additional death, to 67 (95% CI, 49-118) for patients with eGFR >90 mL/min/1.73 m(2).

CONCLUSIONS

Our findings suggest that there is potential for important public health gains by increasing the routine use of statin therapy for patients with lower levels of kidney function.

Non-cancer mortality in workers in the meat and delicatessen departments of supermarkets (1950-2006)

We studied non-cancer mortality in 10,701 workers in the meat and delicatessen departments of supermarkets because they have increased exposure to a variety of microorganisms that infect and cause disease in food animals such as cattle, pigs, sheep, and poultry, to which subjects in the general population are also exposed, albeit to a lesser degree. These workers were also exposed to fumes from the wrapping machine. Standardized mortality ratios were estimated in the cohort as a whole and in race/sex subgroups, using the US population for comparison. Study subjects were followed up from January 1950 to December 2006. Significantly increased deaths from diabetes, ischemic heart disease, pulmonary embolism, chronic bronchitis, peritonitis, intracranial and intraspinal abscess, other bacterial diseases, and significantly decreased deaths from diffuse diseases of connective tissue, functional diseases of the heart, intracerebral hemorrhage, occlusion/stenosis of the precerebral and cerebral arteries, and various types of accidents were observed in certain race/sex subgroups or in the cohort as a whole. The observed increased risks of several infectious conditions suggest that the increased occupational exposure to microorganisms may be responsible for at least some of the observed excess deaths, while exposure to fumes may also contribute to the excess of chronic bronchitis. The findings are important not only for supermarket workers and other workers in the meat and poultry industries, but also because the general population is exposed to these microorganisms found in food animals and their products. Nested case-control studies within cohorts that include both workers in supermarkets and other sectors of the meat and poultry industries, are now needed to examine specific risks from occupational exposures while adequately controlling for confounding factors, so that the role of these infectious agents in the occurrence of these diseases in workers and in general population subjects can be adequately assessed.

Abstract A27: Risk of hematopoietic cancer associated mortality among workers in the poultry slaughtering and processing industries

Objectives: Previous occupational cohort studies among poultry workers have revealed an excess risk of cancer-related mortality, including deaths due to hematopoietic malignancies. However, specific occupational and non-occupational exposures contributing to this excess risk have yet to be identified. Poultry workers are particularly at high risk since an average of 175,000 chickens are killed daily in poultry plants in the United States. This brings poultry workers into intimate contact with their blood, organs, and secretions, which may harbor transmissible oncogenic viruses. Moreover, they are exposed to potentially carcinogenic chemicals that are emitted during packaging and preparation. Hence, our study was conducted to provide preliminary evidence of which specific poultry related and non-poultry related occupational tasks increase the risk of mortality from hematopoietic cancer among poultry workers.

Methods: A pilot case-cohort study was conducted using a combined cohort of 30,411 highly exposed poultry workers and 16,408 control subjects. Exposures pertaining to poultry and non-poultry related tasks were self-reported through telephone interviews from controls and next-of-kin for cases. Hematopoietic cancer mortality risk was assessed using logistic regression odds ratios (OR) and proportional hazard ratios (HR).

Results: One hundred fifty-two cases of hematopoietic cancer occurred in this cohort between January 1, 1990 and December 31, 2003. Since this is a feasibility study, exhaustive attempts were not made to identify study subjects and their next of kin. Thus, we report here on the first 52 (69%) of the 75 cases whose next-of-kin were traced. Similarly, of the first 214 controls that were traced, 152 (71%) completed interviews. Preliminary analysis is currently underway to identify the specific task exposures contributing to this excess risk.

Conclusion: We expect the results of our study will confirm known risk factors related to hematopoietic cancers, and uncover new risk exposures that have yet to be appreciated in the general population due to their low level exposures. Using high-risk unique populations offers an opportunity to better understand molecular mechanisms that investigators may explore to aid in future drug development.

Citation Format: Saritha Bangara, Martha J. Felini, Subhash Aryal, David Sterling, Eric S. Johnson. Risk of hematopoietic cancer associated mortality among workers in the poultry slaughtering and processing industries. [abstract]. In: Proceedings of the AACR Special Conference on Hematologic Malignancies: Translating Discoveries to Novel Therapies; Sep 20-23, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(17 Suppl):Abstract nr A27.

Systolic BP and Mortality in Older Adults with CKD

BACKGROUND AND OBJECTIVES

Optimal BP targets for older adults with CKD are unclear. This study sought to determine whether a nonlinear relationship between BP and mortality-as described for the broader CKD population and for older adults in the general population-is present for older adults with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A cohort of 21,015 adults age 65-105 years with a moderate or severe reduction in eGFR (<60 ml/min per 1.73 m(2)) were identified within the Kaiser Permanente Northwest Health Maintenance Organization population. The relationship between baseline systolic BP (SBP; ≤120, 121-130, 131-140, 141-150, >150 mmHg; referent, 131-140 mmHg) and all-cause mortality across age groups (65-70, 71-80, and >80 years) was examined; patients were followed for up to 11 years after cohort entry.

RESULTS

The median times at risk were 3.15 years, 3.53 years, and 2.76 years for adults age 65-70, 71-80, and >80 years, respectively. Mortality during follow-up was 19.6% for those age 65-70 years, 33.4% for those age 71-80 years, and 55.7% for those age >80 years. The relationship between SBP and mortality varied as a function of age. The risk of death was highest for patients with the lowest SBP in all age groups. Only among adults age 65-70 years was an SBP>140 mmHg associated with a higher risk of death compared with the referent category. Patterns of age modification of the relationship between SBP and mortality were consistent in all sensitivity analyses.

CONCLUSIONS

In a cohort of older adults, the relationship between SBP and mortality varied systematically with age. A relationship between higher SBP and mortality was present only for younger members of this cohort and not for those older than 70. These results raise the question of whether the relative benefits and harms of lowering BP to recommended targets for older adults with CKD may vary as a function of age.

Cancer mortality in the meat and delicatessen departments of supermarkets (1950-2006)

Meat cutters and meat wrappers in the meat department of supermarkets are exposed to oncogenic viruses present in raw meat from cattle, pigs, sheep, and poultry, and their products (unpasteurized milk and raw eggs). Up to the mid 1970s, meat wrappers were also exposed to carcinogens present in fumes emitted from the machine used to wrap meat. Because of this we studied cancer mortality in a cohort of 10,701 workers in the meat and delicatessen departments of supermarkets, and we report here the findings after the third follow-up. Standardized mortality ratios (SMR) were estimated in the cohort as a whole and in race/sex subgroups, using the US population for comparison. Study subjects were followed up from January 1950 to December 2006. Significantly increased SMRs of 1.3 (95% CI, 1.2-1.5), and 2.7 (95% CI, 1.2-5.3) were recorded for cancers of the lung, and tonsils/oropharynx, respectively, in the entire cohort, affecting nearly all race/sex subgroups. SMRs of 4.6 (95% CI, 1.0-13.6) for cancer of the floor of the mouth, and 2.8 (95% CI, 1.3-5.3) for cancer of the gall bladder and biliary tract were recorded only in White male meatcutters. Significantly decreased SMRs were observed for a few cancers. It is not known if the observed excess of cancers is a result of occupational exposures. However, substantial evidence points to fumes from the wrapping machine as a possible candidate for explaining the excess in female meat wrappers. Nested case-control studies that can examine risks from occupational exposures in greater detail, and adequately control for confounding factors are now needed, to permit specifically investigate the role of the oncogenic viruses, fumes and non-occupational risk factors in the occurrence of these cancers. The findings are important, not only occupationally but also because the general population may also experience these exposures, albeit to a lesser degree.

Predicting mortality in older adults with kidney disease: a pragmatic prediction model

OBJECTIVES

To develop mortality risk prediction models for older adults with chronic kidney disease (CKD) that include comorbidities and measures of health status and use not associated with particular comorbid conditions (nondisease-specific measures).

DESIGN

Retrospective cohort study.

SETTING

Kaiser Permanente Northwest (KPNW) Health Maintenance Organization.

PARTICIPANTS

Individuals with severe CKD (estimated glomerular filtration rate<30 mL/min per 1.73 m2; N=4,054; n=1,915 aged 65-79, n=2,139 aged ≥80) who received care at KPNW between 2000 and 2008.

MEASUREMENTS

Cox proportional hazards analysis was used to examine the association between selected participant characteristics and all-cause mortality and to generate age group-specific risk prediction models. Predicted and observed risks were evaluated according to quintile. Predictors from the Cox models were translated into a points-based system. Internal validation was used to provide best estimates of how these models might perform in an external population.

RESULTS

The risk prediction models used 16 characteristics to identify participants with the highest risk of mortality at 2 years for adults aged 65 to 79 and 80 and older. Predicted and observed risks agreed within 5% for each quintile; a 4 to 5 times difference in 2-year predicted mortality risk was observed between the highest and lowest quintiles. The c-statistics for each model (0.68-0.69) indicated effective discrimination without evidence of significant overfit (slope shrinkage 0.06-0.09). Models for each age group performed similarly for mortality prediction at 6 months and 2 years in terms of discrimination and calibration.

CONCLUSION

When validated, these risk prediction models may be helpful in supporting discussions about prognosis and treatment decisions sensitive to prognosis in older adults with CKD in real-world clinical settings.

A Cohort Mortality Study of Workers in a Second Soup Manufacturing Plant

The authors previously reported on mortality among workers in a Baltimore soup plant. Increased mortality was observed for cancers of the floor of the mouth, rectosigmoid colon/rectum/anus, epilepsy, and chronic nephritis. Here, the authors report on mortality on a second soup plant in the same locality. Excess mortality was similarly recorded for cancers of the tonsils/oropharynx, rectosigmoid colon/rectum/anus, and lung and myelofibrosis. Excess risk from cardiovascular, cerebrovascular, kidney, and infectious diseases was also observed. These 2 studies are important because firstly, to the authors' knowledge, they are the only reports of mortality in this occupational group in spite of their having a potential for exposure to hazardous carcinogenic agents. Secondly, there is no information on any exposure assessment in this industry. These 2 reports will draw attention to the need to conduct more detailed exposure and mortality investigations in this little-studied group.

Inter-observer agreement according to malaria parasite density

Background

Recent developments in diagnostic techniques for malaria, particularly DNA probes and sero-immunology, have raised questions as to how these techniques might be used to facilitate malaria diagnosis at the most peripheral levels of the primary health care system. At present, malaria diagnosis is based on the standard microscopic examination of blood films in most field epidemiologic studies and is likely to remain so in the immediate future in Africa. The objective of this study was to assess inter-observer agreement for the examination of Giemsa-stained slides for Plasmodium falciparum parasites.

Methods

Children aged 0 to 10 years were enrolled yearly in Bancoumana village (West Africa), mainly during the transmission season (June to October). The blood smears obtained from the persistently negative children in June 1996, August 1996, October 1996 and March 1997 were systematically re-examined. A stratified random sample (10%) proportional to the following parasite density classes 1–100, 101–5000, and 5001 and over was taken from the slides collected. The kappa statistics and the intra-class correlation were used as measures of agreement the first and the second slide examinations.

Results

The weighted kappa statistic, widely used as a chance-corrected measure for nominal agreement, showed excellent inter-observer agreement (κ_w=0.7926; 95% CI [0.7588, 0.8263]; p=0.01). The intra-class correlation co-efficient had the same value of 0.7926 confirming the appropriateness of the weighted kappa statistic. Inter-observer agreement for slides read as negative by one observer, or as containing more than 100 parasites per μl, was excellent: 97% (493/506) and 92% (145/158), respectively. In contrast, the inter-observer agreement for slides read by one observer as containing 1–100 parasites/μl was poor, 36% (96/268).

Conclusions

In field conditions in Mali, there was a high reproducibility for slides reported as negative or as having more than 100 parasites per μl. However, smears with readings of 1–100 parasites per μl were less reproducible and should be re-examined carefully.

The ankle-brachial index for peripheral artery disease screening and cardiovascular disease prediction among asymptomatic adults: a systematic evidence review for the U.S. Preventive Services Task Force

BACKGROUND

Screening for peripheral artery disease (PAD) may reduce morbidity and mortality.

PURPOSE

To review the evidence on the ability of the ankle-brachial index (ABI) to predict cardiovascular disease (CVD) morbidity and mortality independent of Framingham Risk Score (FRS) factors in asymptomatic adults and on the benefits and harms of treating screen-detected adults with PAD.

DATA SOURCES

MEDLINE and the Cochrane Central Register of Controlled Trials (1996 to September 2012), clinical trial registries, reference lists, and experts.

STUDY SELECTION

English-language, population-based prognostic studies evaluating the ABI in addition to the FRS and treatment trials or studies of treatment harms in screen-detected adults with PAD.

DATA EXTRACTION

Dual quality assessment and abstraction of relevant study details.

DATA SYNTHESIS

One large meta-analysis (n = 43 919) showed that the ABI could reclassify 10-year risk for coronary artery disease (CAD), but it did not report measures of appropriate reclassification (the net reclassification improvement [NRI]). Four heterogeneous risk prediction studies showed that the magnitude of the NRI was probably small when the ABI was added to the FRS to predict CAD or CVD events. Of 2 treatment trials meeting inclusion criteria, 1 large trial (n = 3350) showed that low-dose aspirin did not prevent CVD events in persons with a screen-detected low ABI but may have increased the risk for major bleeding events.

LIMITATIONS

Most prognostic studies did not allow for calculation of a bias-corrected NRI. Evidence on treatment benefits and harms was limited to aspirin and was scant.

CONCLUSION

Adding the ABI to the FRS probably has limited value for predicting CAD or CVD. Treatment benefits for asymptomatic individuals with screen-detected PAD are not established.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Dabigatran bleed risk with closed head injuries: are we prepared?

OBJECT

The direct thrombin inhibitor dabigatran has recently been approved in the US as an alternative to warfarin. The lack of guidelines, protocols, and an established specific antidote to reverse the anticoagulation effect of dabigatran potentially increases the rates of morbidity and mortality in patients with closed head injury (CHI). Confronted with this new problem, the authors reviewed their initial clinical experience.

METHODS

The authors retrospectively reviewed all cases of adult patients (age ≥ 18 years) who sustained CHI secondary to ground-level falls and who presented to the authors' provisional regional Level I trauma center between February 2011 and May 2011. The authors divided these patients into 3 groups based on anticoagulant therapy: dabigatran, warfarin, and no anticoagulants.

RESULTS

Between February 2011 and May 2011, CHIs from ground-level falls were sustained by 5 patients while on dabigatran, by 15 patients on warfarin, and by 25 patients who were not on anticoagulants. The treatment of the patients on dabigatran at the authors' institution had great diversity. Repeat CT scans obtained during reversal showed 4 of 5 patients with new or expanded hemorrhages in the dabigatran group, whereas the warfarin group had 3 of 15 (p = 0.03). The overall mortality rate for patients sustaining CHI on dabigatran was 2 (40%) of 5, whereas that of the warfarin group was 0 (0%) of 15 (p = 0.05).

CONCLUSIONS

It is critical for physicians involved in the care of patients with CHI on dabigatran to be aware of an elevated mortality rate if no treatment protocol or guideline is in place. The authors will soon implement a reversal management protocol for patients with CHI on dabigatran at their institution in an attempt to improve efficacy and safety in their treatment approach.

Correlates of higher-dose opioid medication use for low back pain in primary care

Factors associated with high-dose opioid therapy for noncancer pain are poorly understood. We documented the prevalence of high-dose opioid use as well as associated demographic, clinical, and health service utilization correlates among low back pain patients. Patients prescribed higher doses of opioids (≥100 mg/day morphine equivalent at last dispensing; n = 453) and receiving opioids for 90+ consecutive days were compared to 2 groups: lower-dose opioid group (1-99 mg/day; n = 4,815) or no-opioid group (n = 10,184). Higher-dose opioid use occurred in 2.9% of patients who received any opioids and in 8.6% of patients who received opioids long-term. The median dose in the higher-dose group was 180.0 mg/day. Compared to the no-opioid group, higher-dose users reported poorer health. Compared to either comparison group, patients in the higher-dose group had higher rates of mental health and substance use disorders, concurrent sedative-hypnotic use (60.5%; n = 274), and health service utilization. After adjusting for select covariates, male gender (odds ratio [OR] = 1.68, 95% confidence interval [CI] = 1.37-2.06), higher comorbidity, Medicare coverage (OR = 1.65, 95% CI = 1.22-2.23), any mental health or substance use diagnosis (OR = 1.58, 95% CI = 1.28-1.95), co-prescriptions of sedative-hypnotics (OR = 1.75, 95% CI = 1.42-2.16), and more emergency department and specialty pain clinic visits were associated with higher likelihood of high-dose prescriptions.

PERSPECTIVE

Higher-dose opioid therapy is being prescribed to 8.6% of back pain patients who receive long-term opioids. These patients had higher mental health and medical comorbidities and co-prescriptions of sedative-hypnotics, raising potential safety concerns.

Surgical outcomes of total knee replacement according to diabetes status and glycemic control, 2001 to 2009

BACKGROUND

Poor glycemic control in patients with diabetes may be associated with adverse surgical outcomes. We sought to determine the association of diabetes status and preoperative glycemic control with several surgical outcomes, including revision arthroplasty and deep infection.

METHODS

We conducted a retrospective cohort study in five regions of a large integrated health-care organization. Eligible subjects, identified from the Kaiser Permanente Total Joint Replacement Registry, underwent an elective first primary total knee arthroplasty during 2001 through 2009. Data on demographics, diabetes status, preoperative hemoglobin A1c (HbA1c) level, and comorbid conditions were obtained from electronic medical records. Subjects were classified as nondiabetic, diabetic with HbA1c < 7% (controlled diabetes), or diabetic with HbA1c ≥ 7% (uncontrolled diabetes). Outcomes were deep venous thrombosis or pulmonary embolism within ninety days after surgery and revision surgery, deep infection, incident myocardial infarction, and all-cause rehospitalization within one year after surgery. Patients without diabetes were the reference group in all analyses. All models were adjusted for age, sex, body mass index, and Charlson Comorbidity Index.

RESULTS

Of 40,491 patients who underwent total knee arthroplasty, 7567 (18.7%) had diabetes, 464 (1.1%) underwent revision arthroplasty, and 287 (0.7%) developed a deep infection. Compared with the patients without diabetes, no association between controlled diabetes (HbA1c < 7%) and the risk of revision (odds ratio [OR], 1.32; 95% confidence interval [CI], 0.99 to 1.76), risk of deep infection (OR, 1.31; 95% CI, 0.92 to 1.86), or risk of deep venous thrombosis or pulmonary embolism (OR, 0.84; 95% CI, 0.60 to 1.17) was observed. Similarly, compared with patients without diabetes, no association between uncontrolled diabetes (HbA1c ≥ 7%) and the risk of revision (OR, 1.03; 95% CI, 0.68 to 1.54), risk of deep infection (OR, 0.55; 95% CI 0.29 to 1.06), or risk of deep venous thrombosis or pulmonary embolism (OR, 0.70; 95% CI, 0.43 to 1.13) was observed.

CONCLUSIONS

No significantly increased risk of revision arthroplasty, deep infection, or deep venous thrombosis was found in patients with diabetes (as defined on the basis of preoperative HbA1c levels and other criteria) compared with patients without diabetes in the study population of patients who underwent elective total knee arthroplasty.

The incident user design in comparative effectiveness research

Comparative effectiveness research includes cohort studies and registries of interventions. When investigators design such studies, how important is it to follow patients from the day they initiated treatment with the study interventions? Our article considers this question and related issues to start a dialogue on the value of the incident user design in comparative effectiveness research. By incident user design, we mean a study that sets the cohort's inception date according to patients' new use of an intervention. In contrast, most epidemiologic studies enroll patients who were currently or recently using an intervention when follow-up began. We take the incident user design as a reasonable default strategy because it reduces biases that can impact non-randomized studies, especially when investigators use healthcare databases. We review case studies where investigators have explored the consequences of designing a cohort study by restricting to incident users, but most of the discussion has been informed by expert opinion, not by systematic evidence.

Predicting costs of care in heart failure patients

BACKGROUND

Identifying heart failure patients most likely to suffer poor outcomes is an essential part of delivering interventions to those most likely to benefit. We sought a comprehensive account of heart failure events and their cumulative economic burden by examining patient characteristics that predict increased cost or poor outcomes.

METHODS

We collected electronic medical data from members of a large HMO who had a heart failure diagnosis and an echocardiogram from 1999-2004, and followed them for one year. We examined the role of demographics, clinical and laboratory findings, comorbid disease and whether the heart failure was incident, as well as mortality. We used regression methods appropriate for censored cost data.

RESULTS

Of the 4,696 patients, 8% were incident. Several diseases were associated with significantly higher and economically relevant cost changes, including atrial fibrillation (15% higher), coronary artery disease (14% higher), chronic lung disease (29% higher), depression (36% higher), diabetes (38% higher) and hyperlipidemia (21% higher). Some factors were associated with costs in a counterintuitive fashion (i.e. lower costs in the presence of the factor) including age, ejection fraction and anemia. But anemia and ejection fraction were also associated with a higher death rate.

CONCLUSIONS

Close control of factors that are independently associated with higher cost or poor outcomes may be important for disease management. Analysis of costs in a disease like heart failure that has a high death rate underscores the need for economic methods to consider how mortality should best be considered in costing studies.

Clinician's use of automated reports of estimated glomerular filtration rate: a qualitative study

BACKGROUND

There is a growing awareness in primary care of the importance of identifying patients with chronic kidney disease (CKD) so that they can receive appropriate clinical care; one method that has been widely embraced is the use of automated reporting of estimated glomerular filtration rate (eGFR) by clinical laboratories. We undertook a qualitative study to examine how clinicians use eGFR in clinical decision making, patient communication issues, barriers to use of eGFR, and suggestions to improve the clinical usefulness of eGFR reports.

METHODS

Our study used qualitative methods with structured interviews among primary care clinicians including both physicians and allied health providers, recruited from Kaiser Permanente Northwest, a non-profit health maintenance organization.

RESULTS

We found that clinicians generally held favorable views toward eGFR reporting but did not use eGFR to replace serum creatinine in their clinical decision-making. Clinicians used eGFR as a tool to help identify CKD, educate patients about their kidney function and make treatment decisions. Barriers noted by several clinicians included a desire for greater education regarding care for patients with CKD and tools to facilitate discussion of eGFR findings with patients.

CONCLUSIONS

The manner in which clinicians use eGFRs appears to be more complex than previously understood, and our study illustrates some of the efforts that might be usefully undertaken (e.g. specific clinician education) when encouraging further promulgation of eGFR reporting and usage.

Should measuring haemoglobin among chronic kidney disease patients be a performance measure?

OBJECTIVE

We attempted to: (1) to assess whether or not adequate evidence exists to advocate the measurement of anaemia in chronic kidney disease as a performance measure; and (2) to determine what the appropriate benchmarks might be for health systems seeking to implement this performance measure.

DESIGN

Our study was conducted in two phases: (1) we used the United States Preventive Service Task Force chain of evidence methodology to determine six key questions that were subsequently reviewed to determine if adequate evidence existed to recommend haemoglobin testing among patients with chronic kidney disease; and (2) in order to establish a benchmark for a potential performance measure we measured the number of patients who had a test for anaemia during the preceding year and during the preceding three years. We established these benchmarks using chronic kidney disease defined both by estimated glomerular filtration rate and ICD-9 codes.

SETTING

Benchmarking was undertaken at Kaiser Permanente Northwest, which serves the Portland, Oregon and Vancouver, Washington metropolitan area, and Kaiser Permanente Georgia, which serves the Atlanta metropolitan area.

PARTICIPANTS

Patients with chronic kidney disease identified by either estimated glomerular filtration rate or ICD-9 code. MAIN OUTCOMES MEASUREMENT: Serum haemoglobin

INTERVENTION

This was an observational study.

RESULTS

Our review of the evidence found no direct evidence that testing for anaemia among patients with chronic kidney disease improved patient morbidity or mortality. The ideal test for anaemia was serum haemoglobin. We found that available treatments of anaemia improve fatigue, but may increase mortality and stoke. We also found that an overwhelming majority of patients with chronic kidney disease defined by either estimated glomerular filtration rate or ICD-9 codes, over one or three years had had a haemoglobin measurement.

CONCLUSION

There is currently inadequate evidence to recommend haemoglobin measurement among patients with chronic kidney disease as a performance measure. In addition, most patients with chronic kidney disease have already had haemoglobin measurement, minimizing the potential benefit of a performance measure.

Sickle cell trait protects against Plasmodium falciparum infection

Although sickle cell trait protects against severe disease due to Plasmodium falciparum, it has not been clear whether sickle trait also protects against asymptomatic infection (parasitemia). To address this question, the authors identified 171 persistently smear-negative children and 450 asymptomatic persistently smear-positive children in Bancoumana, Mali (June 1996 to June 1998). They then followed both groups for 2 years using a cohort-based strategy. Among the 171 children with persistently negative smears, the median time for conversion to smear-positive was longer for children with sickle trait than for children without (274 vs. 108 days, P < 0.001; Cox hazard ratio = 0.56, 95% confidence interval: 0.33, 0.96; P = 0.036). Similar differences were found in the median times to reinfection after spontaneous clearance without treatment (365 days vs. 184 days; P = 0.01). Alternatively, among the 450 asymptomatic children with persistently positive smears, the median time for conversion to smear-negative (spontaneous clearance) was shorter for children with sickle trait than for children without (190 vs. 365 days; P = 0.02). These protective effects of sickle trait against asymptomatic P. falciparum infection under conditions of natural transmission were demonstrable using a cohort-based approach but not when the same data were examined using a cross-sectional approach.

Clostridium difficile infection, Colorado and the northwestern United States, 2007

To determine the incidence of Clostridium difficile infection during 2007, we examined infection in adult inpatient and outpatient members of a managed-care organization. Incidence was 14.9 C. difficile infections per 10,000 patient-years. Extrapolating this rate to US adults, we estimate that 284,875 C. difficile infections occurred during 2007.

Epidemiology and healthcare costs of incident Clostridium difficile infections identified in the outpatient healthcare setting

OBJECTIVE

To describe the epidemiology and healthcare costs of Clostridium difficile infection (CDI) identified in the outpatient setting.

DESIGN

Population-based, retrospective cohort study.

PATIENTS

Kaiser Permanente Colorado and Kaiser Permanente Northwest members between June 1, 2005, and September 30, 2008.

METHODS

We identified persons with incident CDI and classified CDI by whether it was identified in the outpatient or inpatient healthcare setting. We collected information about baseline variables and follow-up healthcare utilization, costs, and outcomes among patients with CDI. We compared characteristics of patients with CDI identified in the outpatient versus inpatient setting.

RESULTS

We identified 3,067 incident CDIs; 56% were identified in the outpatient setting. Few strong, independent predictors of diagnostic setting were identified, although a previous stay in a nonacute healthcare institution (odds ratio [OR], 1.45 [95% confidence interval (CI), 1.13-1.86]) was statistically associated with outpatient-identified CDI, as was age from 50 to 59 years (OR, 1.64 [95% CI, 1.18-2.29]), 60 to 69 years (OR, 1.37 [95% CI, 1.03-1.82]), and 70 to 79 years (OR, 1.36 [95% CI, 1.06-1.74]), when compared with persons aged 80-89 years.

CONCLUSIONS

We found that more than one-half of incident CDIs in this population were identified in the outpatient setting. Patients with outpatient-identified CDI were younger with fewer comorbidities, although they frequently had previous exposure to healthcare. These data suggest that practitioners should be aware of CDI and obtain appropriate diagnostic testing on outpatients with CDI symptoms.

Proteinuria among patients with chronic kidney disease: a performance measure for improving patient outcomes

BACKGROUND

In an effort to improve identification and treatment of patients with chronic kidney disease (CKD), the National Kidney Foundation (NKF) developed the Kidney Disease Quality Outcomes Initiative (KDQOI) clinical practice guidelines, which include measurement of proteinuria among all patients with CKD who are not receiving chronic dialysis therapy. Encouraging dissemination and utilization of these guidelines may be enhanced by the development of performance measures. The question of whether adequate evidence exists to advocate for the measurement of proteinuria in CKD as a performance measure was explored.

METHODS

The US Preventive Services Task Force "chain of evidence" framework was used to guide evidence synthesis from the systematic review. Five questions were applied to specific links in the evidence chain: (1) Is there direct evidence that testing for proteinuria improves health outcomes? (2) What is the yield of testing, in terms of both accuracy and reliability of the test and the prevalence of undiagnosed proteinuria? (3) What adverse effects result from testing a person for proteinuria? (4) Does treatment of proteinuria as a result of testing provide an incremental benefit in health outcomes? and (5) What adverse effects result from treating a person for proteinuria? The systematic search specifically targeted meta-analyses and systematic reviews.

FINDINGS

The systematic review revealed no direct evidence that testing for proteinuria among patients with CKD reduced incidence of end-stage renal disease (ESRD). However, the strong links between testing, treatment, and outcome suggest a correlation between proteinuria testing and ESRD.

CONCLUSIONS

Current evidence suggests that proteinuria testing (using the albumin-to-creatinine ratio [ACR]) among patients with CKD would be an appropriate health care quality performance measure for improving patient outcomes.