Methods for Evaluating Respondent Attrition in Web-Based Surveys

Background: Electronic surveys are convenient, cost effective, and increasingly popular tools for collecting information. While the online platform allows researchers to recruit and enroll more participants, there is an increased risk of participant dropout in Web-based research. Often, these dropout trends are simply reported, adjusted for, or ignored altogether. Objective: To propose a conceptual framework that analyzes respondent attrition and demonstrates the utility of these methods with existing survey data. Methods: First, we suggest visualization of attrition trends using bar charts and survival curves. Next, we propose a generalized linear mixed model (GLMM) to detect or confirm significant attrition points. Finally, we suggest applications of existing statistical methods to investigate the effect of internal survey characteristics and patient characteristics on dropout. In order to apply this framework, we conducted a case study; a seventeen-item Informed Decision-Making (IDM) module addressing how and why patients make decisions about cancer screening. Results: Using the framework, we were able to find significant attrition points at Questions 4, 6, 7, and 9, and were also able to identify participant responses and characteristics associated with dropout at these points and overall. Conclusions: When these methods were applied to survey data, significant attrition trends were revealed, both visually and empirically, that can inspire researchers to investigate the factors associated with survey dropout, address whether survey completion is associated with health outcomes, and compare attrition patterns between groups. The framework can be used to extract information beyond simple responses, can be useful during survey development, and can help determine the external validity of survey results

Identifying Attrition Phases in Survey Data: Applicability and Assessment Study

Background: Although Web-based questionnaires are an efficient, increasingly popular mode of data collection, their utility is often challenged by high participant dropout. Researchers can gain insight into potential causes of high participant dropout by analyzing the dropout patterns. Objective: This study proposed the application of and assessed the use of user-specified and existing hypothesis testing methods in a novel setting—survey dropout data—to identify phases of higher or lower survey dropout. Methods: First, we proposed the application of user-specified thresholds to identify abrupt differences in the dropout rate. Second, we proposed the application of 2 existing hypothesis testing methods to detect significant differences in participant dropout. We assessed these methods through a simulation study and through application to a case study, featuring a questionnaire addressing decision-making surrounding cancer screening. Results: The user-specified method set to a low threshold performed best at accurately detecting phases of high attrition in both the simulation study and test case application, although all proposed methods were too sensitive. Conclusions: The user-specified method set to a low threshold correctly identified the attrition phases. Hypothesis testing methods, although sensitive at times, were unable to accurately identify the attrition phases. These results strengthen the case for further development of and research surrounding the science of attrition

A state-level study of opioid use disorder treatment access and neonatal abstinence syndrome

Background Adult opioid use and neonatal abstinence syndrome (NAS) are growing public health problems in the United States (U.S.). Our objective was to determine how opioid use disorder treatment access impacts the relationship between adult opioid use and NAS. Methods We conducted a cross-sectional state-level ecologic study using 36 states with available Healthcare Cost and Utilization Project State Inpatient Databases in 2014. Opioid use disorder treatment access was determined by the: 1) proportion of people needing but not receiving substance use treatment, 2) density of buprenorphine-waivered physicians, and 3) proportion of individuals in outpatient treatment programs (OTPs). The incidence of NAS was defined as ICD-9 code 779.5 (drug withdrawal syndrome in newborn) from any discharge diagnosis field per 1000 live births in that state. Results Unmet need for substance use disorder treatment correlated with NAS (r = 0.54, 95% CI: 0.26–0.73). The correlation between adult illicit drug use/dependence and NAS was higher in states with a lower density of buprenorphine-waivered physicians and individuals in OTPs. Conclusions Measures of opioid use disorder treatment access dampened the correlation between illicit drug use/dependence and NAS. Future studies using community- or individual-level data may be better poised to answer the question of whether or not opioid use disorder treatment access improves NAS relative to adult opioid use

Potentials in vegetable oils and various nutrients of eighteen varieties of Niger Cucurbitaceae

Citrullus Colocynthis and Lagenaria siceraria are two species of Cucurbitaceae whose seeds are used for the production of dough, cakes and edible oils in Niger. Yield in seeds of 18 varieties belonging to these two species were assessed on the Faculty experimental field. The average berries production was 17 berries per plant the first year in contrast 6 the second year. The best productivity was achieved with Citrullus colocynthis which gave 82 berries per plant the 1st year. The average yield in seeds was 180.15 kg/ha the first year and 704.30 kg/ha the second year. The determination of the physicochemical characteristics showed water, ashes, fat, and protein contents which vary respectively from 7 to 9.50%, 4.13 to 4.84%, 18 to 47% and 11 to 35%. The yield in seeds oil varied from 13.7 to 134 L per ha in the first year and 0.26 liters to 800 L per ha the 2nd year. These are the first studies on Cucurbitaceae which link agronomic and physicochemical characteristics of seeds. They showed very important nutrient contents and oil yield, and even higher than some conventionaloilseeds. Extraction of oils from these seeds could meet the need of the populations.Keywords: Cucurbitaceae, Niger, yield, seeds, oils, food security

Harnessing Information Technology to Inform Patients Facing Routine Decisions: Cancer Screening as a Test Case

PURPOSE Technology could transform routine decision making by anticipating patients’ information needs, assessing where patients are with decisions and preferences, personalizing educational experiences, facilitating patient-clinician information exchange, and supporting follow-up. This study evaluated whether patients and clinicians will use such a decision module and its impact on care, using 3 cancer screening decisions as test cases. METHODS Twelve practices with 55,453 patients using a patient portal participated in this prospective observational cohort study. Participation was open to patients who might face a cancer screening decision: women aged 40 to 49 who had not had a mammogram in 2 years, men aged 55 to 69 who had not had a prostate-specific antigen test in 2 years, and adults aged 50 to 74 overdue for colorectal cancer screening. Data sources included module responses, electronic health record data, and a postencounter survey. RESULTS In 1 year, one-fifth of the portal users (11,458 patients) faced a potential cancer screening decision. Among these patients, 20.6% started and 7.9% completed the decision module. Fully 47.2% of module completers shared responses with their clinician. After their next office visit, 57.8% of those surveyed thought their clinician had seen their responses, and many reported the module made their appointment more productive (40.7%), helped engage them in the decision (47.7%), broadened their knowledge (48.1%), and improved communication (37.5%). CONCLUSIONS Many patients face decisions that can be anticipated and proactively facilitated through technology. Although use of technology has the potential to make visits more efficient and effective, cultural, workflow, and technical changes are needed before it could be widely disseminated

Persistent Impairment in Cerebral Vasoreactivity in Subacute Phase Following Concussion

Concussion diagnosis is characterized by a lack of objective markers, as there is a paucity of better understanding of the pathophysiology. Cerebral vasoreactivity (CVR), an important factor in cerebral blood flow (CBF) regulation with dynamic changes in metabolism can be assessed utilizing manipulation of arterial carbon dioxide. CVR utilizing transcranial Doppler ultrasonography may be a useful, objective vascular biomarker for physiological recovery. PURPOSE: To determine the link between clinical symptoms and CVR on Day-3, Day-21, and Day-90 following a concussion in comparison to the non-injured controls. METHODS: Twenty-seven male and female collegiate athletes (21 ±1years) sustaining a sports-related concussion were enrolled. Age and sports-matched non-injured controls were also enrolled. For the concussed athletes, data were obtained on Day-3, Day-21, and Day-90 (N= 17) following the head injury. Symptom severity and cognition were assessed using the Sports Concussion Assessment Tool-3rd Edition (SCAT-3). Depression was assessed utilizing the Patient Health Questionnaire (PHQ-9). Continuous middle cerebral artery blood flow velocity (MCAV) was obtained with transcranial Doppler ultrasonography (TCD) while subjects were seated in an upright position. End-tidal CO₂ (PetCO₂) was measured with an infrared CO₂ analyzer attached to a nasal cannula. MCAV was evaluated in response to changes in PetCO₂ for 2-minutes each during normal breathing (normocapnia), inspiring a gas mixture containing 8% CO₂, 21% oxygen (hypercapnia), and hyperventilating (hypocapnia). RESULTS: On Day-3 subsequent to the head injury, concussed athletes displayed higher symptom number (2.5±3 vs. 12.1±7; PCONCLUSION: Elevated symptoms and lower cognitive scores on Day-3 were resolved by Day-21 following a sports-related concussion. On the other hand, CVR remained impaired at 90 days following concussion suggesting persistent physiological impairment beyond symptom resolution, which could accentuate secondary injuries during this phase. Future studies with a large sample size and longer follow-up period are needed to validate the use of CVR as an objective marker

Multi-scale biodiversity drives temporal variability in macrosystems

High temporal variability in environmental conditions, populations, and ecological communities can result in species extinctions and outbreaks of agricultural pests and disease vectors, as well as impact industries dependent on reliable provisioning of ecosys- tem services. Yet few empirical studies have focused on testing hypotheses about the drivers of ecological temporal variability at large spatial and temporal scales. Using decadal datasets that span aquatic and terrestrial macrosystems and structural equation modeling, we show that local temporal variability and spatial synchrony increase temporal variability for entire macrosystems. These mechanisms are influenced by environmental heterogeneity, habitat-level species diversity, spatial scale, and the size of the regional species pool. This analysis is among the first to provide a quantitative argument for the value of regional species diversity. Moreover, our conceptual model is generalizable and may help guide management efforts to reduce temporal variability for con- servation or service provisioning in other macrosystems

Stem Cell Transplantation As A Dynamical System: Are Clinical Outcomes Deterministic?

Outcomes in stem cell transplantation (SCT) are modeled using probability theory. However the clinical course following SCT appears to demonstrate many characteristics of dynamical systems, especially when outcomes are considered in the context of immune reconstitution. Dynamical systems tend to evolve over time according to mathematically determined rules. Characteristically, the future states of the system are predicated on the states preceding them, and there is sensitivity to initial conditions. In SCT, the interaction between donor T cells and the recipient may be considered as such a system in which, graft source, conditioning and early immunosuppression profoundly influence immune reconstitution over time. This eventually determines clinical outcomes, either the emergence of tolerance or the development of graft versus host disease. In this paper parallels between SCT and dynamical systems are explored and a conceptual framework for developing mathematical models to understand disparate transplant outcomes is proposed.Comment: 23 pages, 4 figures. Updated version with additional data, 2 new figures and editorial revisions. New authors adde