External validation of a minimal-resource model to predict reduced estimated glomerular filtration rate in people with type 2 diabetes without diagnosis of chronic kidney disease in Mexico: a comparison between country-level and regional performance

Background

Patients with type 2 diabetes are at an increased risk of chronic kidney disease (CKD) hence it is recommended that they receive annual CKD screening. The huge burden of diabetes in Mexico and limited screening resource mean that CKD screening is underperformed. Consequently, patients often have a late diagnosis of CKD. A regional minimal-resource model to support risk-tailored CKD screening in patients with type 2 diabetes has been developed and globally validated. However, population heath and care services between countries within a region are expected to differ. The aim of this study was to evaluate the performance of the model within Mexico and compare this with the performance demonstrated within the Americas in the global validation.

Methods

We performed a retrospective observational study with data from primary care (Clinic Specialized in Diabetes Management in Mexico City), tertiary care (Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán) and the Mexican national survey of health and nutrition (ENSANUT-MC 2016). We applied the minimal-resource model across the datasets and evaluated model performance metrics, with the primary interest in the sensitivity and increase in the positive predictive value (PPV) compared to a screen-everyone approach.

Results

The model was evaluated on 2510 patients from Mexico (primary care: 1358, tertiary care: 735, ENSANUT-MC: 417). Across the Mexico data, the sensitivity was 0.730 (95% CI: 0.689 - 0.779) and the relative increase in PPV was 61.0% (95% CI: 52.1% - 70.8%). These were not statistically different to the regional performance metrics for the Americas (sensitivity: p=0.964; relative improvement: p=0.132), however considerable variability was observed across the data sources.

Conclusion

The minimal-resource model performs consistently in a representative Mexican population sample compared with the Americas regional performance. In primary care settings where screening is underperformed and access to laboratory testing is limited, the model can act as a risk-tailored CKD screening solution, directing screening resources to patients who are at highest risk.

Diagnosis codes underestimate chronic kidney disease incidence compared with eGFR-based evidence: a retrospective observational study of patients with type 2 diabetes in UK primary care

BACKGROUND

Type two diabetes (T2D) is a leading cause of both chronic kidney disease (CKD) and onward progression to end-stage renal disease. Timely diagnosis coding of CKD in patients with T2D could lead to improvements in quality of care and patient outcomes.

AIM

To assess the consistency between estimated glomerular filtration rate (eGFR)-based evidence of CKD and CKD diagnosis coding in UK primary care.

DESIGN & SETTING

A retrospective analysis of electronic health record data in a cohort of people with T2D from 60 primary care centres within England between 2012 and 2022.

METHOD

We estimated the incidence rate of CKD per 100 person-years using eGFR-based CKD and diagnosis codes. Logistic regression was applied to establish which attributes were associated with diagnosis coding. Time from eGFR-based CKD to entry of a diagnosis code was summarised using the median and interquartile range.

RESULTS

The overall incidence of CKD was 2.32 (95% confidence interval [CI] = 2.24 to 2.41) and significantly higher for eGFR-based criteria than diagnosis codes: 1.98 (95% CI = 1.90 to 2.05) versus 1.06 (95% CI = 1.00 to 1.11), respectively; P<0.001. Only 45.4% of CKD incidences identified using eGFR-based criteria had a corresponding diagnosis code. Patients who were younger, had a higher CKD stage (G4), had an observed urine albumin-to-creatinine ratio (A1), or no observed HbA1c in the past year were more likely to have a diagnosis code.

CONCLUSION

Diagnosis coding of patients with eGFR-based evidence of CKD in UK primary care is poor within patients with T2D, despite CKD being a well-known complication of diabetes.

Imputation and missing indicators for handling missing data in the development and deployment of clinical prediction models: A simulation study

Background: In clinical prediction modelling, missing data can occur at any stage of the model pipeline; development, validation or deployment. Multiple imputation is often recommended yet challenging to apply at deployment; for example, the outcome cannot be in the imputation model, as recommended under multiple imputation. Regression imputation uses a fitted model to impute the predicted value of missing predictors from observed data, and could offer a pragmatic alternative at deployment. Moreover, the use of missing indicators has been proposed to handle informative missingness, but it is currently unknown how well this method performs in the context of clinical prediction models. Methods: We simulated data under various missing data mechanisms to compare the predictive performance of clinical prediction models developed using both imputation methods. We consider deployment scenarios where missing data is permitted or prohibited, imputation models that use or omit the outcome, and clinical prediction models that include or omit missing indicators. We assume that the missingness mechanism remains constant across the model pipeline. We also apply the proposed strategies to critical care data. Results: With complete data available at deployment, our findings were in line with existing recommendations; that the outcome should be used to impute development data when using multiple imputation and omitted under regression imputation. When missingness is allowed at deployment, omitting the outcome from the imputation model at the development was preferred. Missing indicators improved model performance in many cases but can be harmful under outcome-dependent missingness. Conclusion: We provide evidence that commonly taught principles of handling missing data via multiple imputation may not apply to clinical prediction models, particularly when data can be missing at deployment. We observed comparable predictive performance under multiple imputation and regression imputation. The performance of the missing data handling method must be evaluated on a study-by-study basis, and the most appropriate strategy for handling missing data at development should consider whether missing data are allowed at deployment. Some guidance is provided.

Development of minimal resource pre-screening tools for chronic kidney disease in people with type 2 diabetes

Regular chronic kidney disease (CKD) screening can facilitate earlier diagnosis of CKD and preventative action to reduce the risk of CKD progression. People with type 2 diabetes are at a higher risk of developing CKD; hence, it is recommended that they undergo annual screening. However, resources may be limited, particularly in lower-to-middle income countries, and those at the highest risk of having an abnormal CKD screening result should be prioritised for screening. We have developed models to determine which patients are at a high risk of renal impairment. We have shown that, for people with type 2 diabetes and no previous diagnosis of CKD stage 3-5, it is possible to use age, gender, body mass index, duration of type 2 diabetes and blood pressure information to detect those at a higher risk of a reduced glomerular filtration rate. When blood measurements are available, triglyceride and cholesterol measurements can be used to improve the estimate of the risk. Even though risk factors were associated with an increased urine albumin:creatinine ratio, we found no clinical benefit of using the model over a screen-all approach.

POS1303 METHOTREXATE RESPONSE IN PEDIATRIC NON-INFECTIOUS UVEITIS

Background

Children with chronic non-infectious uveitis (NIU) are at risk for sight-threatening complications. Methotrexate (MTX) is the preferred first-line systemic treatment. Initial therapeutic response takes 3-6 months to achieve NIU control, leading to prolonged glucocorticoid use. Moreover, at least 50-70% of children fail to fully respond and may accrue ocular damage while awaiting MTX response.

Objectives

To identify features of children with NIU that are associated with MTX failure.

Methods

We included children who started MTX monotherapy for NIU. We collected demographics, NIU features (type, location, & complications), ANA status, and clinical examination. We characterized children as MTX responders or non-responders. MTX responders are those whose NIU was controlled, defined by: 1) inactive graded by SUN criteria, 2) absence of new or worsening complications, and 3) requirement for ≤2 drops of prednisolone acetate and no oral glucocorticoids.

Results

Of 47 NIU children, 68% were MTX non-responders (Table 1), having a longer duration of NIU (Odds Ratio [OR]=1.28, [CI=1.03-1.8], p =0.023) and developing more ocular complications (OR=1.95 [CI=1.23-3.38], p=0.017), (ROC Area Under the Curve = 0.85). MTX non-responders were more likely to have anterior and/or posterior synechiae (p = 0.001), cataracts (p=0.015), and ocular hypertension (p=0.039). Treatment included adalimumab: 27, infliximab: 14, tocilizumab: 5, golimumab: 4, etanercept: 3, and abatacept: 2.

Table 1.

Comparison of children with NIU based on MTX response.

Responders n=15Non-responders n=32Caucasian14 (93)27 (84)Hispanic or Latino0 (0)3 (9)Female12 (80)23 (72)Age of NIU onset, yrs, median (IQR)4.3 (2.9 – 12.3)4.6 (2.8 - 7.0)Duration of NIU, yrs, median, (IQR)4.1 (2.6 – 5.3)8.2 (4.7 - 11.3)JIA-NIU10 (67)25 (78)Idiopathic CAU2 (13)3 (9)Other3 (20)4 (12)Bilateral disease12 (80)23 (72)Anterior12 (86)29 (91)Presenting BCVA (LogMAR) worst eye, median (IQR)0.2 (0.1 – 0.3)0.1 (0.0 - 0.2)Average # of total complications/person, median (IQR)1 (0 – 2)2.5 (1.0 – 5.5)ANA positive10 (67)26 (81)Earliest ESR8 (6– 18)12 (8 - 18)Earliest Vitamin D32 (26 – 35)31 (23 - 35)Time on MTX, months, median (IQR)35 (19 - 64)19 (7 - 74)Time from systemic or NIU onset to MTX, yrs, median (IQR)0.3 (0.1 – 0.5)0.2 (0.0 - 0.8)MTX PO6 (40)19 (59)MTX SC13 (87)31 (97)

We performed a sub analysis of children with idiopathic chronic anterior NIU (CAU) and JIA-associated NIU that included children who failed MTX due to intolerance/toxicity (Figure 1). Using Cox proportional hazard regression, 8 idiopathic CAU failed MTX earlier than 38 JIA-associated NIU (HR 2.77, [CI-=1.06-7.27], p=0.039). Results were similar with the inclusion of other types of NIU (p=0.088) (e.g., HLA-B27, non-anterior idiopathic or with systemic disease).

Figure 1.

Kaplan-Meier curve showing freedom from TNFi (mos) stratified by diagnosis

Conclusion

Two out of three children with NIU fail initial MTX monotherapy, exposing them to increased accrual of ocular complications prior to biologic starts. The risk for delay in starting tumor necrosis factor α inhibitors (TNFi) seems higher with CAU. Future studies will examine risk factors that predict MTX response in NIU.

References

[1]McCracken C, Angeles-Han ST, et.al. Timing of infliximab and adalimumab initiation despite methotrexate in children with chronic non-infectious anterior uveitis. Eye (Lond). 2019;33(4):629-39.

[2]Henderson LA, Angeles-Han ST, et.al., Medication use in juvenile uveitis patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry. Pediatr Rheumatol Online J. 2016;14(1):9.

[3]Cooper A, et.al., Failure of methotrexate monotherapy and subsequent response to tumor necrosis factor inhibitors in pediatric non-infectious uveitis (abstract). Arthritis Rheumatol. 2020:72 (suppl 4).

Disclosure of Interests

Sheila Angeles-Han: None declared, Amy Cassedy: None declared, Theresa Hennard: None declared, Mekibib Altaye: None declared, Hermine Brunner Consultant of: Dr. Brunner’s affiliation Cincinnati Children’s Hospital Medical Center has received consulting fees or other remuneration from AstraZeneca, Boehringer Ingelheim, GSK, Roche, Novartis, Pfizer Inc, Takeda, and UBC for the work of Dr. Brunner. Dr. Brunner is a DSMB member for Janssen Pharmaceutical’s trial of ustekinumab pediatric Crohn and Ulcerative colitis., Grant/research support from: Dr. Brunner’s affiliation Cincinnati Children’s Hospital Medical Center has received research grants from BMS, Janssen, Novartis, Pfizer Inc, Roche, and UBC., Eniolami Dosunmu: None declared, Alexei Grom: None declared, Michael Henrickson: None declared, Jennifer Huggins: None declared, Sarah Lopper: None declared, Daniel J Lovell Consultant of: AstraZeneca, Boehringer Ingelheim, GSK, Roche, Novartis, Pfizer Inc, Takeda, and UBC, Grant/research support from: BMS, Janssen, Novartis, Pfizer Inc, Roche, and UBC, Robert Sisk Consultant of: AGTC, Gyroscope, and Leica, Tracy Ting: None declared, Adam Kaufman Consultant of: Consultant for Alcon, Bausch & Lomb, and 1800contacts, not related or relevant to study content., Virginia Utz: None declared

Informative presence and observation in routine health data: A review of methodology for clinical risk prediction

Objective

Informative presence (IP) is the phenomenon whereby the presence or absence of patient data is potentially informative with respect to their health condition, with informative observation (IO) being the longitudinal equivalent. These phenomena predominantly exist within routinely collected healthcare data, in which data collection is driven by the clinical requirements of patients and clinicians. The extent to which IP and IO are considered when using such data to develop clinical prediction models (CPMs) is unknown, as is the existing methodology aiming at handling these issues. This review aims to synthesize such existing methodology, thereby helping identify an agenda for future methodological work.

Materials and Methods

A systematic literature search was conducted by 2 independent reviewers using prespecified keywords.

Results

Thirty-six articles were included. We categorized the methods presented within as derived predictors (including some representation of the measurement process as a predictor in the model), modeling under IP, and latent structures. Including missing indicators or summary measures as predictors is the most commonly presented approach amongst the included studies (24 of 36 articles).

Discussion

This is the first review to collate the literature in this area under a prediction framework. A considerable body relevant of literature exists, and we present ways in which the described methods could be developed further. Guidance is required for specifying the conditions under which each method should be used to enable applied prediction modelers to use these methods.

Conclusions

A growing recognition of IP and IO exists within the literature, and methodology is increasingly becoming available to leverage these phenomena for prediction purposes. IP and IO should be approached differently in a prediction context than when the primary goal is explanation. The work included in this review has demonstrated theoretical and empirical benefits of incorporating IP and IO, and therefore we recommend that applied health researchers consider incorporating these methods in their work.

Toward a framework for the design, implementation, and reporting of methodology scoping reviews

BACKGROUND AND OBJECTIVE

In view of the growth of published articles, there is an increasing need for studies that summarize scientific research. An increasingly common review is a "methodology scoping review," which provides a summary of existing analytical methods, techniques and software that have been proposed or applied in research articles to address an analytical problem or further an analytical approach. However, guidelines for their design, implementation, and reporting are limited.

METHODS

Drawing on the experiences of the authors, which were consolidated through a series of face-to-face workshops, we summarize the challenges inherent in conducting a methodology scoping review and offer suggestions of best practice to promote future guideline development.

RESULTS

We identified three challenges of conducting a methodology scoping review. First, identification of search terms; one cannot usually define the search terms a priori, and the language used for a particular method can vary across the literature. Second, the scope of the review requires careful consideration because new methodology is often not described (in full) within abstracts. Third, many new methods are motivated by a specific clinical question, where the methodology may only be documented in supplementary materials. We formulated several recommendations that build upon existing review guidelines. These recommendations ranged from an iterative approach to defining search terms through to screening and data extraction processes.

CONCLUSION

Although methodology scoping reviews are an important aspect of research, there is currently a lack of guidelines to standardize their design, implementation, and reporting. We recommend a wider discussion on this topic.

Missing data should be handled differently for prediction than for description or causal explanation

Missing data are much studied in epidemiology and statistics. Theoretical development and application of methods for handling missing data have mostly been conducted in the context of prospective research data and with a goal of description or causal explanation. However, it is now common to build predictive models using routinely collected data, where missing patterns may convey important information, and one might take a pragmatic approach to optimizing prediction. Therefore, different methods to handle missing data may be preferred. Furthermore, an underappreciated issue in prediction modeling is that the missing data method used in model development may not match the method used when a model is deployed. This may lead to overoptimistic assessments of model performance. For prediction, particularly with routinely collected data, methods for handling missing data that incorporate information within the missingness pattern should be explored and further developed. Where missing data methods differ between model development and model deployment, the implications of this must be explicitly evaluated. The trade-off between building a prediction model that is causally principled, and building a prediction model that maximizes the use of all available information, should be carefully considered and will depend on the intended use of the model.

Effect of Low-Sodium versus Conventional Sodium Dialysate on Left Ventricular Mass in Home and Self-Care Satellite Facility Hemodialysis Patients: A Randomized Clinical Trial

BACKGROUND

Fluid overload in patients undergoing hemodialysis contributes to cardiovascular morbidity and mortality. There is a global trend to lower dialysate sodium with the goal of reducing fluid overload.

METHODS

To investigate whether lower dialysate sodium during hemodialysis reduces left ventricular mass, we conducted a randomized trial in which patients received either low-sodium dialysate (135 mM) or conventional dialysate (140 mM) for 12 months. We included participants who were aged >18 years old, had a predialysis serum sodium ≥135 mM, and were receiving hemodialysis at home or a self-care satellite facility. Exclusion criteria included hemodialysis frequency >3.5 times per week and use of sodium profiling or hemodiafiltration. The main outcome was left ventricular mass index by cardiac magnetic resonance imaging.

RESULTS

The 99 participants had a median age of 51 years old; 67 were men, 31 had diabetes mellitus, and 59 had left ventricular hypertrophy. Over 12 months of follow-up, relative to control, a dialysate sodium concentration of 135 mmol/L did not change the left ventricular mass index, despite significant reductions at 6 and 12 months in interdialytic weight gain, in extracellular fluid volume, and in plasma B-type natriuretic peptide concentration (ratio of intervention to control). The intervention increased intradialytic hypotension (odds ratio [OR], 7.5; 95% confidence interval [95% CI], 1.1 to 49.8 at 6 months and OR, 3.6; 95% CI, 0.5 to 28.8 at 12 months). Five participants in the intervention arm could not complete the trial because of hypotension. We found no effect on health-related quality of life measures, perceived thirst or xerostomia, or dietary sodium intake.

CONCLUSIONS

Dialysate sodium of 135 mmol/L did not reduce left ventricular mass relative to control, despite improving fluid status.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

The Australian New Zealand Clinical Trials Registry, ACTRN12611000975998.

Integrating health, education and culture in predicting Pacific children's English receptive vocabulary at 6 years: A classification tree approach

AIM

Pacific children fare poorly on health and educational outcomes, including literacy. Early interventions are considered critical in reducing educational disparities. A prediction model was constructed to analyse the factors associated with Pacific children's English receptive vocabulary, an important component of English language development.

METHODS

A birth cohort study of Pacific children was used to construct a classification tree model and predict the proportions of Pacific children who performed strongly in a standardised test of English receptive vocabulary at 6 years of age (n = 1019). Classification trees were constructed using 10-fold cross-validation (CV) and pruned using the one-standard-error rule. Prediction errors were directly estimated using leave-one-out CV.

RESULTS

Analyses of misclassification errors from the pruned model gave false negative and positive rates of 19 and 19% from re-substitution and 54 and 21% from leave-one-out CV estimation, respectively. Of the predictors, maternal acculturation, small birthweight and performance in early developmental screening test at 4 years of age were found to have the highest goodness of split.

CONCLUSIONS

The cultural environment to which Pacific children were exposed in early childhood, indicated by the maternal acculturation, was more crucial in distinguishing children with strong English-receptive vocabulary skills than socio-economic or prenatal conditions. This highlights the importance of integrating the cultural environment into designing measures for facilitating Pacific children's language development.

Vitamin D3 supplementation in adults with bronchiectasis: A pilot study

Vitamin D supplementation prevents acute respiratory infections and, through modulating innate and adaptive immunity, could have a potential role in bronchiectasis management. The primary aims of this pilot study were to assess serum 25-hydroxyvitamin D (25(OH)D) levels in New Zealand adults with bronchiectasis, and their 25(OH)D levels after vitamin D3 supplementation. Adults with bronchiectasis received an initial 2.5 mg vitamin D3 oral loading dose and 0.625 mg vitamin D3 weekly for 24 weeks. The primary outcome was serum 25(OH)D levels before and after vitamin D3 supplementation. Secondary outcomes (time to first infective exacerbation, exacerbation frequency, spirometry, health-related quality of life measures, sputum bacteriology and cell counts and chronic rhinosinusitis) were also assessed. This study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN 12612001222831). The initial, average 25(OH)D level was 71 nmol/L (95% confidence interval (CI): [58, 84]), rising to 218 nmol/L (95% CI: [199, 237]) at 12 weeks and 205 nmol/L (95% CI: [186, 224]) at 24 weeks. The initial serum cathelicidin level was 25 nmol/L (95% CI: [17, 33]), rising to 102 nmol/L (95% CI: [48, 156]) at 12 weeks and 151 nmol/L (95% CI: [97, 205]) at 24 weeks. Over the 24-week study period, we observed statistically significant changes of 1.11 (95% CI: [0.08, 2.14]) in the Leicester Cough Questionnaire and -1.97 (95% CI: [-3.71, -0.23]) in the Dartmouth COOP charts score. No significant adverse effects were recorded. Many New Zealand adults with bronchiectasis have adequate 25(OH)D levels. Weekly vitamin D3 supplementation significantly improved 25(OH)D levels.

Distinguishing transient versus stable aspects of depression in New Zealand Pacific Island children using Generalizability Theory

BACKGROUND

The distinction between temporary versus enduring or state/trait aspects of depression is important. More precise distinction would improve understanding of the aetiology of depression and those aspects most amenable to intervention thus identifying more homogeneous, dynamic targets for clinical trials. Generalizability Theory has been proposed as useful for disentangling state and trait components of psychopathology.

METHODS

We applied Generalizability Theory to determine the relative contributions of temporary and enduring aspects of depression in a widely used screening measure of depression the - 10-item Children's Depression Inventory (CDI-10; Kovacs, 1985). Participants were children of Pacific Island descent living in New Zealand (n = 668). Data were collected at ages - 9, 11, and 14 years.

RESULTS

The CDI-10 demonstrated acceptable generalizability across occasions (G = 0.79) with about one third of variance in total scores attributed to temporary and two thirds to more enduring aspects of depression. There were no other significant sources of error variance. Two items were identified as more sensitive than the remaining eight to more dynamic symptoms.

LIMITATIONS

Studies with briefer test-retest intervals are warranted. Use of this Pacific Island cohort limits generalizability of findings to other cultures and ethnicities. No data were collected on whether participants had received intervention for depression.

CONCLUSIONS

While the CDI-10 reliably measures both stable and transient aspects of depression in children, the scale does not permit clear distinction between them. We advocate application of Generalizability Theory for developing state/trait depression measures and determining which existing measures are most suitable for capturing modifiable features of depression.

Efficacy of a Web-Based Safety Decision Aid for Women Experiencing Intimate Partner Violence: Randomized Controlled Trial

Background

Intimate partner violence (IPV) is a human rights violation and leading health burden for women. Safety planning is a hallmark of specialist family violence intervention, yet only a small proportion of women access formal services. A Web-based safety decision aid may reach a wide audience of women experiencing IPV and offer the opportunity to prioritize and plan for safety for themselves and their families.

Objective

The aim of this study was to test the efficacy of a Web-based safety decision aid (isafe) for women experiencing IPV.

Methods

We conducted a fully automated Web-based two-arm parallel randomized controlled trial (RCT) in a general population of New Zealand women who had experienced IPV in the past 6 months. Computer-generated randomization was based on a minimization scheme with stratification by severity of violence and children. Women were randomly assigned to the password-protected intervention website (safety priority setting, danger assessment, and tailored action plan components) or control website (standard, nonindividualized information). Primary endpoints were self-reported mental health (Center for Epidemiologic Studies Depression Scale-Revised, CESD-R) and IPV exposure (Severity of Violence Against Women Scale, SVAWS) at 12-month follow-up. Analyses were by intention to treat.

Results

Women were recruited from September 2012 to September 2014. Participants were aged between 16 and 60 years, 27% (111/412) self-identified as Māori (indigenous New Zealand), and 51% (210/412) reported at baseline that they were unsure of their future plans for their partner relationship. Among the 412 women recruited, retention at 12 months was 87%. The adjusted estimated intervention effect for SVAWS was −12.44 (95% CI −23.35 to −1.54) for Māori and 0.76 (95% CI −5.57 to 7.09) for non-Māori. The adjusted intervention effect for CESD-R was −7.75 (95% CI −15.57 to 0.07) for Māori and 1.36 (−3.16 to 5.88) for non-Māori. No study-related adverse events were reported.

Conclusions

The interactive, individualized Web-based isafe decision aid was effective in reducing IPV exposure limited to indigenous Māori women. Discovery of a treatment effect in a population group that experiences significant health disparities is a welcome, important finding.

Trial Registration

Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12612000708853; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12612000708853 (Archived by Webcite at http://www.webcitation/61MGuVXdK)

Participant Recruitment and Engagement in Automated eHealth Trial Registration: Challenges and Opportunities for Recruiting Women Who Experience Violence

BACKGROUND

Automated eHealth Web-based research trials offer people an accessible, confidential opportunity to engage in research that matters to them. eHealth trials may be particularly useful for sensitive issues when seeking health care may be accompanied by shame and mistrust. Yet little is known about people's early engagement with eHealth trials, from recruitment to preintervention autoregistration processes. A recent randomized controlled trial that tested the effectiveness of an eHealth safety decision aid for New Zealand women in the general population who experienced intimate partner violence (isafe) provided the opportunity to examine recruitment and preintervention participant engagement with a fully automated Web-based registration process. The trial aimed to recruit 340 women within 24 months.

OBJECTIVE

The objective of our study was to examine participant preintervention engagement and recruitment efficiency for the isafe trial, and to analyze dropout through the registration pathway, from recruitment to eligibility screening and consent, to completion of baseline measures.

METHODS

In this case study, data collection sources included the trial recruitment log, Google Analytics reports, registration and program metadata, and costs. Analysis included a qualitative narrative of the recruitment experience and descriptive statistics of preintervention participant engagement and dropout rates. A Koyck model investigated the relationship between Web-based online marketing website advertisements (ads) and participant accrual.

RESULTS

The isafe trial was launched on September 17, 2012. Placement of ads in an online classified advertising platform increased the average number of recruited participants per month from 2 to 25. Over the 23-month recruitment period, the registration website recorded 4176 unique visitors. Among 1003 women meeting eligibility criteria, 51.55% (517) consented to participate; among the 501 women who enrolled (consented, validated, and randomized), 412 (82.2%) were accrued (completed baseline assessments). The majority (n=52, 58%) of the 89 women who dropped out between enrollment and accrual never logged in to the allocated isafe website. Of every 4 accrued women, 3 (314/412, 76.2%) identified the classified ad as their referral source, followed by friends and family (52/412, 12.6%). Women recruited through a friend or relative were more likely to self-identify as indigenous Māori and live in the highest-deprivation areas. Ads increased the accrual rate by a factor of 74 (95% CI 49-112).

CONCLUSIONS

Print advertisements, website links, and networking were costly and inefficient methods for recruiting participants to a Web-based eHealth trial. Researchers are advised to limit their recruitment efforts to Web-based online marketplace and classified advertising platforms, as in the isafe case, or to social media. Online classified advertising in "Jobs-Other-volunteers" successfully recruited a diverse sample of women experiencing intimate partner violence. Preintervention recruitment data provide critical information to inform future research and critical analysis of Web-based eHealth trials.

CLINICALTRIAL

Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12612000708853; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12612000708853 (Archived by WebCite at http://www.webcitation/6lMGuVXdK).

Delirium: comparison of four predictive models in hospitalized critically ill elderly patients

Delirium, a cognitive and behavioral disorder affecting more than one third of all hospitalized elderly patients, is often misdiagnosed or unrecognized by caregivers, leading to higher patient morbidity and mortality rates. Prediction of the disorder, based on known predisposing and precipitating risk factors, can be used to target susceptible patients for prevention and early intervention. Predictive models need to be evaluated for clinical application and predictive value. Therefore, in this study, four predictive models were applied on a case-by-case basis to an elderly sample of 10 delirious patients and 10 nondelirious patients to determine sensitivity, specificity, and predictive values in a critical care setting. Results indicated six individual significant variables in these models: age, infection, dementia, blood urea nitrogen-to-creatinine ratio, severe illness, and comorbidity. A final multivariate model, derived from all variables, exhibited a sensitivity of 100% and specificity of 90% in predicting delirium in this study. Further studies are needed to substantiate these results. Then, identified risk factors can be incorporated into delirium prevention protocols for use by nurses at the bedside.

Isolation of glucagon antagonists by random molecular mutagenesis and screening

Glucagon has an important role in the regulation of glucose homeostasis, and glucagon antagonists may be effective therapeutic agents in the control of diabetes mellitus. We were able to identify a number of analogs with antagonist activity by creating libraries of mutant glucagon coding sequences, expressing them in a yeast (Saccharomyces cerevisiae) secretion system, and screening for clones that produce analogs that inhibit the glucagon stimulation of rat hepatocyte membrane adenylate cyclase. These libraries were constructed by allowing random misincorporation during the synthesis of oligonucleotides that contained the complete coding sequence for mammalian glucagon or for an analog (desHis1-glucagon) that had partial antagonist activity. We developed and used a simplified screening assay to test culture broths from > 3500 individual transformant yeast clones for their ability to inhibit glucagon-dependent adenylate cyclase activity. Ultimately, > 20 different analogs with antagonist activity were identified by recovering and sequencing plasmid DNA from yeast strains that were positive in the screening assay. Interestingly, several analogs were identified repeatedly in independent yeast clones and certain amino acid substitutions occurred in more than one analog. This clustering of randomly isolated mutations clearly delineates the regions of the glucagon molecule that are important for designing improved glucagon antagonists. A subset of the antagonists identified in yeast broth were produced by peptide synthesis to confirm their activities as pure compounds.

Multicenter phase II study of brequinar sodium in patients with advanced gastrointestinal cancer

Eighty-six patients with advanced colorectal, gastric or pancreatic carcinoma and no prior exposure to chemotherapy were treated with brequinar sodium. Brequinar was administered at a median weekly dose of 1200 mg/m2 intravenously. The toxicity was moderate, with thirty patients (35%) experiencing grade 3 or 4 toxicity. Objective responses were observed in 1/32 evaluable colorectal and 2/29 evaluable gastric carcinoma patients. There were no objective responses in 17 evaluable pancreatic cancer patients. We conclude that, at this dose and schedule, brequinar does not have sufficient activity in these gastrointestinal malignancies to warrant further evaluation.

Multicenter phase II study of brequinar sodium in patients with advanced lung cancer

A total of 53 patients with advanced lung cancer [non-small-cell (NSC), 21; small-cell (SC), 32] were treated with brequinar sodium. All of the NSC patients were chemotherapy-naive, but 31/32 (97%) SC patients had failed a multiagent chemotherapy program prior to study entry. Brequinar was given intravenously at a median weekly dose of 1200 mg/m2. The toxicity was moderate, with 19 patients (36%) experiencing grade 3 or 4 toxicity. Objective responses were observed in one NSC and two SC patients. We conclude that at this dose and on this schedule, brequinar does not have sufficient activity in patients with NSC or in patients with previously treated SC to warrant further evaluation. However, since responses were observed in previously treated SC lung-cancer patients, further evaluation in chemotherapy-naive patients may be warranted.

Non-consensus DNA sequences function in a cell-type-specific enhancer of the mouse class II MHC gene A alpha

Class II MHC proteins play central roles in controlling immune cell repertoire and responses. These roles depend on precise regulation of the level and cell-type specificity of class II gene expression. Instances of both coordinate and non-coordinate regulation of the multiple class II genes have been described. A 1.3 kb region of the class II MHC gene A alpha has previously been shown to activate transcription in a cell-type specific fashion that correlated with the expression of A alpha. The mouse A alpha gene differs from other class II MHC genes in that its conserved X region also contains the CRE/ATF DNA motif TGACGTCA. Substitution mutations were introduced into the 1.3 kb region such that the CRE/ATF (X2) motif was altered, but not the adjacent X1 or Y box motifs. Controls confirmed that these mutations eliminated the binding of nuclear proteins to the CRE/ATF motif and reduced transcriptional activity as much as mutation of the Y box. In addition, a new positive transcription element was identified far upstream from the conserved X-Y region, centered on position -970. The sequence of this region does not resemble previously described transcription elements or other MHC class II 5' flanking sequences. The activity of this element was absolutely dependent on the presence of the X-Y region. These data are most consistent with a model in which functionally important sequences unique to a single class II MHC gene can be intimately interposed between conserved MHC transcription elements, and non-consensus elements upstream from the conserved region contribute to control of A alpha.

Protracted infusion of 5-FU with weekly low-dose cisplatin as second-line therapy in patients with metastatic colorectal cancer who have failed 5-FU monotherapy

Forty four patients who had documented progression of metastatic colorectal cancer while receiving 5-fluorouracil (5-FU) monotherapy were treated with continuous infusion 5-FU, 300 mg/mg2/day, plus weekly low-dose cisplatin, 20 mg/m2. Treatment was given in 12-week cycles, consisting of 8 weeks of chemotherapy followed by a 4-week rest period, and was well tolerated. Three of 23 patients (13%) who had failed bolus 5-FU but not been exposed previously to infusional 5-FU responded. Of 21 patients who had failed infusional 55-FU monotherapy, only one (5%) responded. Time to progression (5.7 vs. 1.8 months) and survival (12 vs. 5.5 months) were significantly longer for patients who had not previously received infusional 5-FU but who had failed bolus schedules, compared with patients who had previously failed infusional 5-FU (p less than .001).

A displacement pump procedure to load extracts for automated gel permeation chromatography

Automated gel permeation chromatography (GPC) effectively separates lipids from pesticides in sample extracts that contain fat. Using a large syringe to load sample extracts manually onto GPC models having 5 mL holding loops is awkward, slow, and potentially hazardous. Loading with a small-volume displacement pump, however, is convenient and fast (ca 1 loop every 20 s). And more importantly, the analyst is not exposed to toxic organic vapors because the loading pump and its connecting lines do not leak in the way that a syringe does.

Cancer-associated hemolytic-uremic syndrome: analysis of 85 cases from a national registry

A registry of suspected cases of cancer-associated hemolytic-uremic syndrome (C-HUS) was established in May 1984. Records of 85 patients from the registry, all with history of cancer, hematocrit less than or equal to 25%, platelet count less than 100,000, and serum creatinine greater than or equal to 1.6 mg/dL were subjected to in-depth analysis. Eighty-nine percent of patients had adenocarcinoma, including 26% with gastric cancer. Microangiopathic hemolysis was reported in 83 patients; coagulation studies were normal with rare exception. Bone marrow examination ruled out chemotherapy-induced myelosuppression in 68 of 85. Thirty-five percent of patients were without evident cancer at time of syndrome development. Mitomycin (MMC) was part of the treatment regimen in 84 patients; all but nine received a cumulative dose greater than 60 mg. Pulmonary edema, generally noncardiogenic, developed in 65% of patients, often after blood product transfusions. C-HUS has a high mortality: over 50% of patients died of or with syndrome, most within 8 weeks of syndrome development. Conventional treatment was ineffective, although ten of 21 treated with staphylococcal protein A (SPA) immunopheresis showed significant responses. Statistical analysis found only absence of obvious tumor and treatment with SPA to suggest favorable prognosis. C-HUS is distinguishable from related syndromes such as childhood HUS, thrombotic thrombocytopenic purpura (TTP), consumption coagulopathy, and microangiopathic hemolysis associated with advanced carcinoma. MMC is likely involved in the development of C-HUS; the risk of developing C-HUS after treatment with MMC is between 4% and 15%. However, possible bias in patients referred to the registry and reports of non-MMC C-HUS cases must be remembered. Recommendations include careful monitoring of renal and hematologic function in patients treated with MMC, aggressive nontransfusion in patients with suspected C-HUS, and consideration of treatment with SPA immunopheresis in patients with definite syndrome.

Cochleovestibular toxicity related to dichloromethotrexate

A 69-year-old man receiving monotherapy for lung cancer with dichloromethotrexate (DCM), and without exposure to other chemotherapeutic agents or known ototoxic drugs, developed profound cochleovestibular dysfunction. The initial presentation was vestibular. This resolved, but unilateral hearing loss ensued and continued to progress to a total of 80 db loss in the low frequency range and 40 db in the high range, despite discontinuation of the drug. Because DCM may be used in combination with the known ototoxin cisplatin, the potential of DCM as an ototoxin should also be considered in such patients.