Abstract Background Randomized pre-post designs, with outcomes measured at baseline and after treatment, have been commonly used to compare the clinical effectiveness of two competing treatments. ...There are vast, but often conflicting, amount of information in current literature about the best analytic methods for pre-post designs. It is challenging for applied researchers to make an informed choice. Methods We discuss six methods commonly used in literature: one way analysis of variance (“ ANOVA” ) , analysis of covariance main effect and interaction models on the post-treatment score (“ ANCOVA I ” and “ ANCOVA II ”), ANOVA on the change score between the baseline and post-treatment scores (“ ANOVA-Change ”), repeated measures (“ RM” ) and constrained repeated measures (“ cRM” ) models on the baseline and post-treatment scores as joint outcomes. We review a number of study endpoints in randomized pre-post designs and identify the mean difference in the post-treatment score as the common treatment effect that all six methods target. We delineate the underlying differences and connections between these competing methods in homogeneous and heterogeneous study populations. Results ANCOVA and cRM outperform other alternative methods because their treatment effect estimators have the smallest variances. cRM has comparable performance to ANCOVA I in the homogeneous scenario and to ANCOVA II in the heterogeneous scenario. In spite of that, ANCOVA has several advantages over cRM: i) the baseline score is adjusted as covariate because it is not an outcome by definition; ii) it is very convenient to incorporate other baseline variables and easy to handle complex heteroscedasticity patterns in a linear regression framework. Conclusions ANCOVA is a simple and the most efficient approach for analyzing pre-post randomized designs.
The analysis of covariance (ANCOVA) or repeated measures (RM) models are often used to compare the treatment effect between different arms in pre-post randomized studies. ANCOVA adjusts the baseline ...score as a covariate in regression models. RM treats both the baseline and post-randomization scores as outcome variables. We aim to establish the underlying connections between ANCOVA and a constrained RM (“cRM”). We start with the interrelated concepts in a pre-post randomized designs: homogeneous vs. heterogeneous study populations, the marginal vs. the conditional treatment effect, and homogeneity vs. heterogeneity of treatment effect. We then demonstrate the asymptotic equivalence between the ANCOVA and cRM estimators for the marginal treatment effect and discuss the conditions under which ANCOVA needs to include a baseline score by treatment interaction term. In particular, an ANCOVA interaction model with a mean centered baseline score can assess both the marginal treatment effect and the heterogeneity in the conditional treatment effect. However, the ordinary least squares (OLS)-based inference is not valid for unconditional inference because this interaction model typically has heteroskedastic errors, and ordinary least squares treats the sample mean of the baseline score as a known parameter. We propose a bootstrap and a heteroskedasticity consistent variance estimator for heteroskedastic ANCOVA. Our simulation studies demonstrate that the proposed methods provide valid inferences for testing both the marginal treatment effect and the heterogeneity of treatment effect using an ANCOVA interaction model. We used an acupuncture headache trial to elucidate the proposed approaches.
Pre-post parallel group randomized designs have been frequently used to compare the effectiveness of competing treatment strategies and the ordinary least squares (OLS)-based analysis of covariance ...model (ANCOVA) is a routine analytic approach. In many scenarios, the associations between the baseline and the post-randomization scores could differ between the treatment and control arms, which justifies the inclusion of the treatment by baseline score interaction in ANCOVA. This heterogeneity may also cause heteroscedastic errors in ANCOVA. In this study, we compared the performances of the ANCOVA models with and without the interaction term in estimating the marginal treatment effect in a heterogeneous two-arm pre-post design. We explored the relationship between the two nested ANCOVA models from the perspective of an omitted variable bias problem and further revealed the reasons why the usual ANCOVA may fail in heterogeneous scenario through the discussion of the three types of variances associated with the ANCOVA estimators of the marginal treatment effect: the target unconditional variance, the conditional variance allowing unequal error variances, and the OLS conditional variance derived under the assumption of constant error variance. We demonstrated analytically and with simulations that the proposed heteroscadastic-consistent variance estimators provide valid unconditional inference for ANCOVA, and the ANCOVA interaction model is more powerful than the ANCOVA main effect model when a design is unbalanced.
In this article, a structure based on one-dimensional photonic crystals that can be used for both angle sensing and refractive index sensing is proposed, which is achieved by optical Tamm state. ...Under Bragg scattering, its features are investigated by the transfer matrix method. This sensing structure is based on a multi-frequency absorption structure, which can achieve an absorption rate higher than 0.9 for three to four frequency points at the same time. The studied results demonstrate that the absorption peaks of such an absorption structure can be changed from three to four by adjusting the number of periods and silver layer thickness. Absorption peaks can occur red and blue shifts employing tailoring the thickness of defect and the angle of the incident light. By altering the thickness of the defect and the number of periods, the interval between the absorption peaks can be dominated. They are all with high-quality factors and can be used to bring about a high absorption sensor for the refractive index or angle. When it acts as a refractive index sensor, the operating range can cover from 2 to 2.7, whose sensitivity and average figure of merit are 32.3 THz/RIU and 100. If the presented device is used as an angle sensor, those values will become 0.5 THz/degree and 1.2, and its measuring range is from 25° to 70°. It can be said that the emergence of this special sensing structure will be possible to have a broad application prospect in the field of measurement.
Guided by the development of an innovative economy, students' innovative education has also become the focus of talent training. This research aims to realize the intelligent evaluation of students' ...innovation ability. In this article, we proposed an innovation ability framework that integrates students' psychological state and innovation evaluation indicators. Firstly, the qualitative description of psychological data is quantified using the Delphi method. Secondly, this article proposes an improved particle swarm optimization-long short-term memory (IPSO-LSTM) model to achieve high-precision evaluation and classification of innovation capabilities. The classification accuracy of this model for excellent, general and failed innovation capabilities is up to 95.3%. Finally, the characteristic contribution analysis of psychological and innovative ability characteristics is carried out. The results show that the evaluation of creative ability contributes more than 50% to the psychological aspects of excellent students. This shows the importance of psychological status on creative ability and provides a theoretical basis for integrating innovative education and psychological education in the future.
Abstract Objectives Postnatal depression has emerged as a major public health concern, which has deleterious effects on the well-being of the entire family. The aim of this study was to examine the ...predictive role of prenatal family sense of coherence, stress, social support and family, and marital functioning; the effect that any changes in these factors from pregnancy to postpartum; and partner's depressive symptoms on depressive symptoms at 6 months postpartum. Methods This study used a longitudinal design. A convenience sample of 200 childbearing couples in Hong Kong completed assessments of family sense of coherence, stress, social support, family, and marital functioning and depressive symptoms during pregnancy and at 6 months postpartum. Multiple regression analyses were employed. Results The results showed that a low level of family sense of coherence and a high level of depressive symptoms during pregnancy and partner's depressive symptoms were significantly associated with an increase in depressive symptoms for both mothers and fathers at 6 months postpartum. A lack of social support was significantly associated with increased risk of depressive symptoms for mothers, but not for fathers. Conclusion The results suggest that couple-based interventions that foster a sense of family coherence may be helpful in promoting parental well-being. Well-designed trials to test the effects of such interventions are recommended for future research.
Objectives
Transition to parenthood is characterized by a high level of stress, which can affect couples’ relationship and quality of life. Limited research compares the relationships and trends in ...stress, marital relationship and quality of life between both couples across the perinatal period. This study examined the associations, changes over time and gender differences in the stress, marital relationship and quality of life of Chinese couples during the perinatal period.
Methods
A convenience sample of 130 couples participated in this longitudinal study. Data on the assessment of stress, marital relationship and quality of life were collected by validated measures during the second or third trimester of pregnancy and at 6 weeks, 6 months and 12 months postpartum.
Results
Both couples experienced an increased level of stress at 6 weeks postpartum and a gradual decline in marital relationship from pregnancy to 1 year postpartum. The mental component of women’s quality of life declined sharply at 6 weeks postpartum and recovered at 6 months postpartum. The physical component of quality of life showed gradual improvements from pregnancy to 1 year postpartum for the women, but a decline for the men. The women showed more stress and poorer marital relationship and quality of life than their partners, and the women’s levels of stress, marital relationship and mental component of quality of life were closely related to those of their partners’ across the perinatal period. Stress was related negatively to marital relationship and quality of life, and a positive marital relationship was associated with better quality of life during the perinatal period.
Conclusion
The study highlights the need to adopt couple-based approaches in clinical practice directed at helping partners develop realistic expectations and manage stress, which are essential to promoting marital relationships and quality of life during the transition to parenthood.
The father's involvement in childrearing can positively influence health outcomes not only for the man himself but also for his partner and their children. However, the experience of first‐time ...fatherhood is limited in Chinese communities. The aim of this study is to explore men's experience of first‐time fatherhood and coping in Hong Kong. An exploratory qualitative design was used. A purposive sample of 44 first‐time Chinese fathers who had participated in a couple‐based cognitive‐behavioral intervention for postnatal depression were recruited for telephone interviews at 1–3 months postpartum. Data were collected by a semistructured interview guide and analyzed using thematic analysis. The process involved in men's transition to first‐time fatherhood reveals four major themes: changes in daily life, new paternal roles and responsibilities, availability of resources to enhance adaptation, and coping strategies. The findings have implications for health care professionals and policy‐makers in the provision of comprehensive perinatal care and family‐friendly policies to aid men's transition to first‐time fatherhood in Chinese communities.
Abstract
In this paper, a spatially selective (SS) structure is investigated through the critical jump characteristic when the permittivity of the epsilon-negative (ENG) materials approaches zero. In ...the range where the incident frequency of the TE wave is 5.1–5.6 c d
−1
and that of the TM wave is 5.0–5.7 c d
−1
, the transmittance exceeds 0.85 and the squareness factor (SF) surpasses 0.9. By adjusting the electronic plasma frequency to affect the position of epsilon-near-zero (ENZ) frequency, a wide-angle control of the SS characteristic extent is produced. Using the fragility of the critical angle to the background analyte medium, a variable refractive index sensor is proposed. When the electronic plasma frequency is continuously altered, the analyte with the measurement range of 1.1–1.3, 1.3–1.5, 1.5–1.7, or 1.7–1.9 can be detected. The corresponding sensitivity is 57.1 degrees/RIU, 48.8 degrees/RIU, 40.0 degrees/RIU, or 32.8 degrees/RIU. The elongation in the thickness of ENG materials contributes to the improvement of the SF, executing the discrimination of
Vibrio cholera, E. coli
, and
Shigella flexneri
. The effects of losses on device performance are also briefly considered. Different from previous studies, the proposed SS selective structure adopts a new ENZ mechanism, can simplify the design of the structure to a certain extent and has a possibility in the design of highly sensitive sensors.
As health information technology grows, secondary uses of personal health information offer promise in advancing research, public health, and health care. Public perceptions about sharing personal ...health data are important for establishing and evaluating ethical and regulatory structures to oversee the use of these data.
To measure patient preferences about sharing their electronic health information for secondary purposes (other than their own health care).
In this conjoint analysis study, we surveyed 3336 adults (568 Hispanic, 500 non-Hispanic African American, and 2268 non-Hispanic white); participants were randomized to 6 of 18 scenarios describing secondary uses of electronic health information, constructed with 3 attributes: uses (research, quality improvement, or commercial marketing), users (university hospitals, commercial enterprises, or public health departments), and data sensitivity (whether it included genetic information about their own cancer risk). This design enabled participants to reveal their preferences for secondary uses of their personal health information.
Participants responded to each conjoint scenario by rating their willingness to share their electronic personal health information on a 1 to 10 scale (1 represents low willingness; 10, high willingness). Conjoint analysis yields importance weights reflecting the contribution of a dimension (use, user, or sensitivity) to willingness to share personal health information.
The use of data was a more important factor in the conjoint analysis (importance weight, 64.3%) than the user (importance weight, 32.6%) and data sensitivity (importance weight, 3.1%). In unadjusted linear regression models, marketing uses (β = -1.55), quality improvement uses (β = -0.51), drug company users (β = -0.80), and public health department users (β = -0.52) were associated with less willingness to share health information than research uses and university hospital users (all P < .001). Hispanics and African Americans differentiated less than whites between uses.
Participants cared most about the specific purpose for using their health information, although differences were smaller among racial and ethnic minorities. The user of the information was of secondary importance, and the sensitivity was not a significant factor. These preferences should be considered in policies governing secondary uses of health information.
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