A Comparison of Estimation Methods when an Interaction is Omitted from a Multilevel Model

One of the sources of inaccuracy in parameter estimates of multilevel models is omitted variable bias, caused by the omission of an important predictor. The purpose of this study was to examine the performance of six estimation procedures in estimating the fixed effects when a level-2 interaction term was omitted from a two-level hierarchical linear model. Four alternative estimators (FE, WLS1, WLS2, WLS3) based on the work of Frees (2001) and the Maximum Likelihood (FML, ReML) estimation methods were examined. Findings of the Monte Carlo study revealed that the FML and ReML methods were the least biased methods when a level-2 interaction was omitted from the multilevel model. FML and ReML produced the lowest RMSD values of all six estimation methods regardless of level-2 sample size, ICC, or effect sizes of the level-2 variables. The difference in the performance of the alternative and Maximum Likelihood (ML) procedures diminished as level-2 sample size and ICC increased. The bias in all six estimation methods did not differ much when the effect sizes of the level-2 predictors varied. When the methods were examined using the ECLS data, the results of the Monte Carlo study were confirmed. The ML methods were the least biased of all the methods when a level-2 interaction term was omitted from the model

GENOMICS OF ENDOGLIN PATHWAY IN PREECLAMPSIA

THE GENOMICS OF ENDOGLIN PATHWAY IN PREECLAMPSIA Mandy J. Bell, PhD, RN University of Pittsburgh, 2012 Preeclampsia is a pregnancy disorder that greatly impacts maternal and fetal/neonatal health and wellbeing. This case-control candidate gene association study investigated endoglin pathway genetic variation and its association with preeclampsia. Tagging single nucleotide polymorphisms (tSNPs) in ENG, TGFβ1, TGFβR1, ALK1, and TGFβR2 were genotyped with iPLEX® and TaqMan® in maternal/fetal dyads. The Prenatal Exposures and Preeclampsia Prevention study provided maternal DNA extracted from peripherally collected white blood cell pellets, along with umbilical cord serum we used for fetal DNA extraction. Data on 355 white (181 cases/174 controls) and 60 black (30 cases/30 controls) women matched on ancestry, age, and parity were analyzed. Separate subgroup allele/genotype/haplotype tests were conducted with Chi-square or Fisher’s exact tests. Binary logistic regression provided odds ratios for tSNPs with significant genotype tests. Analysis of maternal/fetal dyads was not conducted, because unlike the maternal samples, the fetal samples did not provide a quality template suitable for iPLEX® data collection. In white women, variation in ENG (rs11792480, rs10121110) and TGFβR2 (rs6550005) was associated with preeclampsia. Allelic frequency distributions in rs11792480, rs10121110, and rs6550005 were significantly different among cases and controls while genotype distributions of rs10121110 and rs6550005 were further associated with preeclampsia (p-values < .05). For rs10121110, women with the AA genotype were 2.290 times more likely to develop preeclampsia compared to the GG genotype (99% CI [1.022, 5.133], p = .008). ENG haplotype TACGA, which contains rs11792480 and rs10121110 risk alleles, was also over-represented in cases (p = .022). In black women, variation in TGFβ1 (rs4803455, rs4803457), TGFβR1 (rs10739778), and TGFβR2 (rs6550005, rs1346907, rs877572) was associated with preeclampsia. Allelic frequency distributions in rs10739778, rs6550005, rs1346907, and rs877572 were significantly different among cases and controls while genotype distributions of rs10739778, rs4803455, and rs4803457 were further associated with preeclampsia (p-values < .05). For rs4803457, women with the CT genotype were 7.437 more times likely to develop preeclampsia compared to the CC genotype (99% CI [1.192, 46.408], p = .005). These results demonstrate that variation in ENG pathway genes is associated with preeclampsia, with different genes from the same pathway contributing to preeclampsia in white compared to black women

Parental perception of facilitators and barriers to health among young children with down syndrome: a qualitative study

BackgroundDespite high rates of obesity and weight-related conditions observed in children with Down syndrome, little is known about how to prevent these conditions.PurposeThe purpose of this study was to identify parent-perceived facilitators and barriers to health for toddlers (12–36 months old) with Down syndrome.Materials and methodsWe conducted in-depth, semi-structured interviews with the mothers of 25 toddlers with Down syndrome. All interviews were conducted using Zoom Video Technology, audio recorded and transcribed before being coded in NVivo software using a structured protocol. Thematic analysis was used to identify themes in perceived facilitators and barriers to health at the level of the child, family, and community. Data were triangulated using reflective journaling, video review of child meals, and member-checking techniques.ResultsWe identified unique themes for facilitators (on the move and sound sleep) and barriers (co-occurring conditions and eating behaviors) at the level of the child. At the level of the family and community, overarching themes that were viewed as either a facilitator or barrier, depending on the context, were identified (role models matter, time is critical, the importance of place, and social support).ConclusionThese themes can help clinicians and researchers tailor their health promotion interventions to meet the unique needs of children with Down syndrome by using strength-based approaches and providing families with the tools to overcome barriers

Test of a conceptual model of uncertainty in children and adolescents with cancer

Despite recognition as a significant stressor in childhood cancer, illness-related uncertainty from the perspective of children remains under-studied. We tested a conceptual model of uncertainty, derived from Mishel’s uncertainty in illness theory, in 68 school-aged children and adolescents with cancer. As hypothesized, uncertainty was significantly related to psychological distress, but only one hypothesized antecedent (parental uncertainty) significantly predicted children’s uncertainty. An alternative model incorporating antecedent developmental factors (age and illness-specific expertise) explained 21% of the variance in child uncertainty; controlling for stage of treatment, uncertainty was higher in children with shorter time since diagnosis, older age, lower cancer knowledge, and higher parental uncertainty. These findings provide the foundation for further studies to understand children’s management of uncertainty and its contribution to psychological adjustment to illness

Self-reported attitudes, skills and use of evidence-based practice among Canadian doctors of chiropractic: a national survey

Objectives: To identify Canadian chiropractors' attitudes, skills and use of evidence based practice (EBP), as well as their level of awareness of previously published chiropractic clinical practice guidelines (CPGs). Methods: 7,200 members of the Canadian Chiropractic Association were invited by e-mail to complete an online version of the Evidence Based practice Attitude & utilisation SurvEy (EBASE) a valid and reliable measure of participant attitudes, skills and use of EBP. Results: Questionnaires were completed by 554 respondents. Most respondents (>75%) held positive attitudes toward EBP. Over half indicated a high level of self-reported skills in EBP, and over 90% expressed an interest in improving these skills. A majority of respondents (65%) reported over half of their practice was based on evidence from clinical research, and only half (52%) agreed that chiropractic CPGs significantly impacted on their practice. Conclusions: While most Canadian chiropractors held positive attitudes towards EBP, believed EBP was useful, and were interested in improving their skills in EBP, many did not use research evidence or CPGs to guide clinical decision making. Our findings should be interpreted cautiously due to the low response rate. (JCCA. 2015 59(4): 332-348) KEY WORDS: chiropractic complementary and alternative medicine evidence-based practice survey Objectifs: Cerner les comportements, les competences et la mise en oeuvre de la pratique factuelle (pratique fondee sur des donnees probantes) des chiropraticiens canadiens, ainsi que leur niveau de connaissance des guides de pratique clinique chiropratiques precedemment publies. Methodes: 7 200 membres de l'Association chiropratique canadienne ont ete invites par courriel pour remplir une version en ligne du sondage sur l'utilisation et le comportement associes a la pratique factuelle une evaluation valable et fiable des comportements, des competences et de la mise en oeuvre de la pratique factuelle par les participants. Resultats: Les questionnaires ont ete remplis par 554 repondants. La plupart des repondants (> 75 %) ont revele des comportements positifs vis-a-vis de la pratique factuelle. Plus de la moitie d'entre eux ont rapporte un niveau eleve d'aptitudes autodeclarees en matiere de pratique factuelle, et plus de 90 % d'entre eux ont fait part de leur interet a ameliorer ces competences. La majorite des repondants (65 %) a indique que plus de la moitie de leur pratique etait fondee sur des donnees probantes issues de la recherche clinique, et seulement la moitie de ces derniers (52 %) a reconnu que les guides de pratique clinique chiropratiques avaient des repercussions importantes sur leur pratique. Conclusions: Si la plupart des chiropraticiens canadiens ont revele des comportements positifs vis-a-vis de la pratique factuelle, pensaient que celle-ci etait utile et etaient interesses a l'idee d'ameliorer leurs competences en la matiere, un grand nombre d'entre eux n'utilisaient pas les donnees probantes issues de la recherche ou les guides de pratique clinique pour orienter leurs prises de decisions cliniques. Nos conclusions doivent etre interpretees avec precaution en raison du faible taux de reponse. (JCCA. 2015 59(4): 332-348) MOTS-CLES: chiropratique, medecine parallele et medecine douce, pratique factuelle, sondag

Use of mHealth Technology for Patient-Reported Outcomes in Community-Dwelling Adults with Acquired Brain Injuries: A Scoping Review.

The purpose of our scoping review was to describe the current use of mHealth technology for long-term assessment of patient-reported outcomes in community-dwelling individuals with acquired brain injury (ABI). Following PRISMA guidelines, we conducted a scoping review of literature meeting these criteria: (1) civilians or military veterans, all ages; (2) self-reported or caregiver-reported outcomes assessed via mobile device in the community (not exclusively clinic/hospital); (3) published in English; (4) published in 2015-2019. We searched Ovid MEDLINE(R) \u3c 1946 to 16 August 2019, MEDLINE InProcess, EPub, Embase, and PsycINFO databases for articles. Thirteen manuscripts representing 12 distinct studies were organized by type of ABI [traumatic brain injury (TBI) and stroke] to extract outcomes, mHealth technology used, design, and inclusion of ecological momentary assessment (EMA). Outcomes included post-concussive, depressive, and affective symptoms, fatigue, daily activities, stroke risk factors, and cognitive exertion. Overall, collecting patient-reported outcomes via mHealth was feasible and acceptable in the chronic ABI population. Studies consistently showed advantage for using EMA despite variability in EMA timing/schedules. To ensure best clinical measurement, research on post-ABI outcomes should consider EMA designs (versus single time-point assessments) that provide the best timing schedules for their respective aims and outcomes and that leverage mHealth for data collection

Quality of recipient-caregiver relationship and psychological distress are correlates of self-care agency after lung transplantation

Self-care behaviors are crucial for following the complex regimen after lung transplantation, yet little is known about recipients’ levels of self-care agency (the capability and willingness to engage in self-care behaviors) and its correlates. We examined levels of self-care agency and recipient characteristics (socio-demographics, psychological distress, quality of relationship with primary lay caregiver, and health locus of control) in 111 recipients. Based on Perceived Self-Care Agency scores, recipients were assigned to either the low or high self-care agency comparison group. Characteristics were compared between groups to identify characteristics likely to be associated with lower self-care agency. Mean (S.D.) score for self-care agency (scale range 53–265) was 223.02 (22.46). Recipients with lowest self-care agency scores reported significantly poorer quality of caregiver relationships (p < .001) and greater psychological distress (p < .001). After controlling for psychological distress, the quality of the recipient-caregiver relationship remained significantly associated with self-care agency. Every one-point decrease in the quality of caregiver relationship increased the risk of low self-care agency by 12%. Recipients with poorer caregiver relationships and greater psychological distress may need additional support to perform the self-care behaviors expected after lung transplantation

An Intervention Fidelity Framework for Technology-Based Behavioral Interventions

Despite the proliferation of health technologies, descriptions of the unique considerations and practical guidance for evaluating intervention fidelity of technology-based behavioral interventions are lacking