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.

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.

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.

CONTEXTE: Les pellicules sont une maladie chronique omniprésente qui a un impact négatif sur la qualité de vie. Un traitement efficace nécessite une administration efficace d'agents bénéfiques pour le cuir chevelu qui contrôlent les niveaux commensaux de Malassezia. L'administration d'agents bénéfiques à partir de shampooings nécessite d'équilibrer de nombreux paramètres techniques pour obtenir le résultat souhaité sans sacrifier des paramètres secondaires tels que les attributs cosmétiques. BUT: Développer des technologies de formulation qui augmentent l'efficacité d'administration du shampooing de l'agent bénéfique pour le cuir chevelu piroctone olamine (PO). Une livraison accrue devrait entraîner une efficacité antipelliculaire accrue. MÉTHODES: La stabilité micellaire et les paramètres d'association ont été quantifiés via les paramètres de tension superficielle dynamique et de diffusion RMN, respectivement. L'administration de PO a été évaluée in vivo à la fois sur la surface du cuir chevelu et sur l'indibula folliculaire à l'aide de procédures d'extraction et d'analyses analytiques. L'efficacité antipelliculaire clinique a été évaluée pour un prototype de technologie d'administration avancée par rapport à la technologie d'administration standard. RÉSULTATS: Des prototypes de shampooing ont été développés pour augmenter l'efficacité de livraison des PO. Des approches à base de tensioactifs et de coacervats polymères ont été développées. Une diminution de la stabilité micellaire entraîne une association plus faible entre le PO et les micelles, ce qui entraîne une rétention plus efficace du PO sur la surface du cuir chevelu et une livraison à l'infundibula. L'augmentation de la densité de charge des polymères cationiques optimise la coacervation, permettant également une meilleure administration de PO. Il a été démontré cliniquement que l'augmentation de l'administration de PO entraîne une efficacité antipelliculaire plus élevée, mesurée à la fois par les squames visibles et les biomarqueurs sous-jacents. CONCLUSION: Des shampooings à libération de PO à efficacité accrue ont été développés en optimisant à la fois les paramètres du tensioactif et du coacervat. L'efficacité de dépôt accrue se traduit par beaucoup plus de produits avec une efficacité antipelliculaire nettement supérieure.

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.

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.

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.

A Case-Cohort Study to Investigate the Excess of Liver Cancer Observed in Workers in Poultry Slaughtering & Processing Plants.

This is a case-cohort study to examine whether the excess of liver cancer deaths observed in workers in poultry plants could be explained by oncogenic viruses and chemical carcinogenic exposures within the plants. A detailed telephone questionnaire was administered, and responses were analyzed by logistic regression. Odds ratios for several indicators of high exposure to oncogenic viruses or chemical carcinogens in poultry plants and related industries were elevated, but not statistically significant, except the odds ratio for direct contact with the blood of meat in kitchens, eating places, etc. Established risk factors were replicated, and new ones identified. The study was unable to unequivocally assess risks due to oncogenic viruses or chemical carcinogenic exposures in poultry plants, mainly because observed elevated risks did not achieve statistical significance. The same also applies to some non-occupational factors. Noteworthy risk factors identified include the increased risks for eating cabbage, mussels, blood sausage, meringue, playing football, and decreased risks for history of frequent intake of soft drinks, gelatin-based meals, vitamins, frequent use of microwave oven to cook, and history of childhood diseases, and nonspecific symptoms. The significance of these findings is unknown, and they will need to be replicated in studies with adequate statistical power.

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.

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.

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.

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.

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.

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 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.

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.

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.

Critical Appraisal for Racial and Ethnic Equity in Clinical Prediction Models Extension: Development of a Critical Appraisal Tool Extension to Assess Racial and Ethnic Equity-Related Risk of Bias for Clinical Prediction Models.

Introduction: Despite mounting evidence that the inclusion of race and ethnicity in clinical prediction models may contribute to health disparities, existing critical appraisal tools do not directly address such equity considerations. Objective: This study developed a critical appraisal tool extension to assess algorithmic bias in clinical prediction models. Methods: A modified e-Delphi approach was utilized to develop and obtain expert consensus on a set of racial and ethnic equity-based signaling questions for appraisal of risk of bias in clinical prediction models. Through a series of virtual meetings, initial pilot application, and an online survey, individuals with expertise in clinical prediction model development, systematic review methodology, and health equity developed and refined this tool. Results: Consensus was reached for ten equity-based signaling questions, which led to the development of the Critical Appraisal for Racial and Ethnic Equity in Clinical Prediction Models (CARE-CPM) extension. This extension is intended for use along with existing critical appraisal tools for clinical prediction models. Conclusion: CARE-CPM provides a valuable risk-of-bias assessment tool extension for clinical prediction models to identify potential algorithmic bias and health equity concerns. Further research is needed to test usability, interrater reliability, and application to decision-makers.

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.

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.