Direction of the relationship between methamphetamine use and positive psychotic symptoms in regular methamphetamine users: evidence from a prospective cohort study

2020 ◽  
pp. 1-7
Author(s):  
Leanne Hides ◽  
Gary Chan ◽  
Sharon Dawe ◽  
Rebecca McKetin ◽  
David J. Kavanagh ◽  
...  
Keyword(s):  
Root Mean Square ◽  
Psychotic Disorder ◽  
Psychiatric Research ◽  
Psychotic Symptoms ◽  
Mean Square ◽  
Methamphetamine Use ◽  
Methamphetamine Dependence ◽  
Bidirectional Relationship ◽  
The Impact ◽  
The Relationship

Background Methamphetamine has been consistently associated with positive psychotic symptoms, but little is known about whether the reverse also occurs. Aims This study determined whether the relationship between methamphetamine use and positive psychotic symptoms is bidirectional over 12 months. The impact of lifetime psychotic disorders and methamphetamine dependence on these relationships was also examined. Method A total of 201 regular (at least monthly) primary methamphetamine users were recruited from free needle and syringe programmes in three Australian cities. Data on the frequency of methamphetamine and other drug use (from Timeline Followback inteviews) and the severity of positive psychotic symptoms (using the Brief Psychiatric Rating Scale) in the past 2 weeks were collected in 12 contiguous monthly face-to-face interviews (mean of 9.14/11 (s.d. = 3.16) follow-ups completed). Diagnoses were derived using the Psychiatric Research Interview for DSM-IV Substance and Mental Disorders. Results The mean age of participants was 31.71 years (s.d. = 8.19) and 39% (n = 77) were women. At baseline 55% (n = 110) were dependent on methamphetamine and 51% (n = 102) had a lifetime psychotic disorder. Cross-lagged dynamic panel models found a significant bidirectional relationship between psychotic symptoms and methamphetamine use (Comparative Fit Index (CFI) = 0.94, standardised root mean square residual (SRMR) = 0.05, root mean square error of approximation (RMSEA) = 0.05, 95% CI 0.04–0.06). The magnitude of the relationship in each direction was similar, and the presence of methamphetamine dependence or a lifetime psychotic disorder did not have an impact on results. Conclusions A dynamic, bidirectional relationship between methamphetamine and psychotic symptoms of similar magnitude in each direction was found over 1 year. This suggests integrated treatments that target methamphetamine, psychotic symptoms and their interrelationship may be of most benefit.

The Relationship of Root Mean Square Value of Electromyography and Isometric Torque of Quadriceps in Normal Subjects

2016 ◽  
Vol 26 (1) ◽  
pp. 58
Author(s):  
Qiurong XIE ◽  
Zheng JIANG ◽  
Qinglu LUO ◽  
Jie LIANG ◽  
Xiaoling WANG ◽  
...  
Keyword(s):  
Root Mean Square ◽  
Normal Subjects ◽  
Mean Square ◽  
Isometric Torque ◽  
Relationship Of ◽  
The Relationship

Examining the Impact of and Sensitivity of Fit Indices to Omitting Covariates Interaction Effect in Multilevel Multiple-Indicator Multiple-Cause Models

2021 ◽  
pp. 001316442199240
Author(s):  
Chunhua Cao ◽  
Eun Sook Kim ◽  
Yi-Hsin Chen ◽  
John Ferron
Keyword(s):  
Root Mean Square ◽  
Interaction Effect ◽  
Intraclass Correlation ◽  
Information Criteria ◽  
Parameter Estimates ◽  
Mean Square ◽  
Fit Indices ◽  
Cluster Number ◽  
Multiple Indicator ◽  
The Impact

This study examined the impact of omitting covariates interaction effect on parameter estimates in multilevel multiple-indicator multiple-cause models as well as the sensitivity of fit indices to model misspecification when the between-level, within-level, or cross-level interaction effect was left out in the models. The parameter estimates produced in the correct and the misspecified models were compared under varying conditions of cluster number, cluster size, intraclass correlation, and the magnitude of the interaction effect in the population model. Results showed that the two main effects were overestimated by approximately half of the size of the interaction effect, and the between-level factor mean was underestimated. None of comparative fit index, Tucker–Lewis index, root mean square error of approximation, and standardized root mean square residual was sensitive to the omission of the interaction effect. The sensitivity of information criteria varied depending majorly on the magnitude of the omitted interaction, as well as the location of the interaction (i.e., at the between level, within level, or cross level). Implications and recommendations based on the findings were discussed.

scholarly journals Relationship Between Millennials and Brand Loyalty: Mediating Brand Loyalty Factors

2017 ◽  
Vol 5 (3) ◽  
pp. 223
Author(s):  
Dhameeth, S. Gehan ◽  
Ochi, Yamamoto
Keyword(s):  
Root Mean Square ◽  
Brand Loyalty ◽  
Structural Equation ◽  
Brand Management ◽  
Management Strategies ◽  
Second Phase ◽  
Mean Square ◽  
Root Mean Square Residual ◽  
Mediating Factors ◽  
The Relationship

<p><em>The purpose of this study is to identify factors (brand elements) that mediate between Millennials and brand loyalty, and to test a theoretical model that includes these mediating factors in describing the relationship between millennials and brand loyalty. The study focused on the key factors that we identified and hypothesized to mediate the relationship between millennials and brand loyalty. The quantitative study surveyed two hundred and fifty-three (n=253) respondents randomly drawn. Structural Equation Modelling (SEM) was used to test a model of the relationship between the mediating factors, millennials and brand loyalty. All model fit parameters were well within acceptable bounds. The Comparative Fit Index (CFI) was 0.999, Root Mean Square Error of Approximation (RMSEA) was 0.018, and Standardized Root Mean Square Residual (SRMR) was 0.022. However, we believe that the model is over-fitting the data, and this is not surprising given that there are 22 variables and 253 data points. These results show promise, but require further investigation in a second phase of the inquiry. This study limited itself to surveying millennials, brand loyalty, and the seven mediating factors we identified and hypothesized to play a role in mediating between them. Based on this study, brand management strategies are proposed.</em><em></em></p>

scholarly journals Impact of different centroid means on the accuracy of orthometric height modelling by geometric geoid method

2020 ◽  
Vol 6 (4) ◽  
pp. 124 ◽  
Author(s):  
Oluyori P. Dare ◽  
Eteje S. Okiemute
Keyword(s):  
Root Mean Square ◽  
Arithmetic Mean ◽  
Orthometric Height ◽  
Harmonic Mean ◽  
Geometric Method ◽  
Mean Square ◽  
Geoid Model ◽  
Microsoft Excel ◽  
Orthometric Heights ◽  
The Impact

<p class="abstract"><strong>Background:</strong> Orthometric height, as well as geoid modelling using the geometric method, requires centroid computation. And this can be obtained using various models, as well as methods. These methods of centroid mean computation have impacts on the accuracy of the geoid model since the basis of the development of the theory of each centroid mean type is different. This paper presents the impact of different centroid means on the accuracy of orthometric height modelling by geometric geoid method.</p><p class="abstract"><strong>Methods:</strong> DGPS observation was carried out to obtain the coordinates and ellipsoidal heights of selected points. The centroid means were computed with the coordinates using three different centroid means models (arithmetic mean, root mean square and harmonic mean). The computed centroid means were entered accordingly into a Microsoft Excel program developed using the Multiquadratic surface to obtain the model orthometric heights at various centroid means. The root means square error (RMSE) index was applied to obtain the accuracy of the model using the known and the model orthometric heights obtained at various centroid means.  </p><p class="abstract"><strong>Results:</strong> The computed accuracy shows that the arithmetic mean method is the best among the three centroid means types.</p><p class="abstract"><strong>Conclusions:</strong> It is concluded that the arithmetic mean method should be adopted for centroid computation, as well as orthometric height modelling using the geometric method.</p>

scholarly journals A systematic review of risk factors for methamphetamine-associated psychosis

2018 ◽  
Vol 52 (6) ◽  
pp. 514-529 ◽  
Author(s):  
Shalini Arunogiri ◽  
James A Foulds ◽  
Rebecca McKetin ◽  
Dan I Lubman
Keyword(s):  
Risk Factors ◽  
Sociodemographic Factors ◽  
Psychotic Symptoms ◽  
Study Quality ◽  
Individual Study ◽  
Methamphetamine Use ◽  
Methamphetamine Dependence ◽  
Study Country ◽  
Quantitative Synthesis ◽  
Newcastle Ottawa Scale

Objective: Chronic methamphetamine use is commonly associated with the development of psychotic symptoms. The predictors and correlates of methamphetamine-associated psychosis are poorly understood. We sought to systematically review factors associated with psychotic symptoms in adults using illicit amphetamine or methamphetamine. Methods: A systematic literature search was performed on MEDLINE (OVID), PsycINFO and EMBASE databases from inception to 8 December 2016. The search strategy combined three concept areas: methamphetamine or amphetamine, psychosis and risk factors. Included studies needed to compare adults using illicit methamphetamine or amphetamine, using a validated measure of psychosis, on a range of risk factors. Of 402 identified articles, we removed 45 duplicates, 320 articles based on abstract/title and 17 ineligible full-text articles, leaving 20 included studies that were conducted in 13 populations. Two co-authors independently extracted the following data from each study: country, setting and design; participant demographic and clinical details; sample size; measure/s used and measures of association between psychosis outcomes and risk factors. Individual study quality was assessed using a modified Newcastle-Ottawa Scale, and strength of evidence was assessed using GRADE criteria. Results: Frequency of methamphetamine use and severity of methamphetamine dependence were consistently found to be associated with psychosis, and sociodemographic factors were not. There was inconsistent evidence available for all other risk factors. Individual study quality was low–moderate for the majority of studies. Heterogeneity in study outcomes precluded quantitative synthesis of outcomes across studies. Conclusion: The most consistent correlates of psychotic symptoms were increased frequency of methamphetamine use and dependence on methamphetamine. The findings of this review highlight the need for targeted assessment and treatment of methamphetamine use in individuals presenting with psychosis.

scholarly journals S131. NEIGHBOURHOOD-LEVEL SOCIAL CAPITAL, MARGINALIZATION, AND THE INCIDENCE OF PSYCHOTIC DISORDERS IN TORONTO, CANADA: A RETROSPECTIVE POPULATION-BASED COHORT STUDY

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S85-S85
Author(s):  
Martin Rotenberg ◽  
Andrew Tuck ◽  
Kelly Anderson ◽  
Kwame McKenzie
Keyword(s):  
Social Capital ◽  
Psychotic Disorder ◽  
Psychotic Disorders ◽  
Population Based ◽  
Ethnic Concentration ◽  
Schizophrenia Spectrum ◽  
Neighbourhood Level ◽  
Incident Cases ◽  
The Impact ◽  
The Relationship

Abstract Background Previous studies have shown mixed results regarding the relationship between social capital and the risk of developing a psychotic disorder, and this has yet to be studied in North America. This study aims to examine the relationship between neighbourhood-level social capital, marginalization, and the incidence of psychotic disorders in Toronto, Canada. Methods A retrospective cohort of people aged 14 to 40 years residing in Toronto, Canada in 1999 (followed to 2008) was constructed from population-based health administrative data. Incident cases of schizophrenia spectrum psychotic disorders were identified using a validated algorithm. Voter participation rates in a municipal election were used as a proxy neighbourhood-level indicator of social capital. Exposure to neighbourhood-level marginalization was obtained from the Ontario Marginalization Index. Poisson regression models adjusting for age and sex were used to calculate incidence rate ratios (IRR) for each social capital quintiles and marginalization quintile. Results In the study cohort (n = 640,000) over the 10-year follow-up period, we identified 4,841 incident cases of schizophrenia spectrum psychotic disorders. We observed elevated rates of psychotic disorders in areas with the highest levels (IRR = 1.13, 95% CI 1.00–1.27) and moderate levels (IRR = 1.23, 95% CI 1.12–1.36) of social capital, when compared to areas with the lowest levels of social capital, after adjusting for neighbourhood-level indicators of marginalization. The risk associated with social capital was not present when analyzed in only the females in the cohort. All neighbourhood marginalization indicators, other than ethnic concentration, were significantly associated with risk. Discussion The risk of developing a psychotic disorder in Toronto, Canada is associated with socioenvironmental exposures. Social capital is associated with risk, however, the impact of social capital on risk differs by sex and social capital quintile. Across the entire cohort, exposure to all neighbourhood-level marginalization indicators, except ethnic concentration, impacts risk. Future research should examine how known individual-level risk factors, including immigration, ethnicity, and family history of a mental disorder may interact with these findings.

Developing a model of the determinants of medication nonadherence in older community-dwelling patients

2019 ◽  
Vol 53 (11) ◽  
pp. 942-954 ◽  
Author(s):  
Affraic McLoughlin ◽  
Kathleen Bennett ◽  
Caitriona Cahir
Keyword(s):  
Root Mean Square ◽  
Direct Relationship ◽  
Community Dwelling ◽  
Mediating Effect ◽  
World Health ◽  
Mean Square ◽  
Medication Nonadherence ◽  
Related Factors ◽  
Older Populations ◽  
The Relationship

Abstract Medication nonadherence is associated with adverse health outcomes in older populations. The aim of this study was to develop a model that describes the relationship between the determinants of nonadherence, per the World Health Organization (WHO) model of nonadherence and the necessity–concerns framework (NCF) and nonadherence in a cohort of older community-dwelling patients. A retrospective cohort study of 855 community-dwelling patients aged ≥70 years from 15 practices. Medication nonadherence was assessed by (i) medication possession ratio (MPR < 80%) and (ii) the median MPR across all drugs dispensed. Patient questionnaires, interviews, and medical records measured the determinants of nonadherence per the WHO and NCF frameworks. Confirmatory factor analysis (CFA) was undertaken to generate the model of best fit. Two structural equation models (SEM) were developed to evaluate the relationship between the WHO factors, the NCF, and nonadherence (Model 1: MPR < 80%, Model 2: median MPR). The CFA produced a reasonable fit (χ2(113) = 203, p < .001; root mean square error of approximation = 0.03; comparative fit index = 0.98, and weighted root mean square residual = 0.97) and adequate internal consistency (r = .26–.40). SEM analysis (Model 1) showed a significant direct relationship between patient-related (β = 0.45, p < .01), socioeconomic (β = 0.20, p < .01), and therapy-related factors (β = −0.27, p < .01) and nonadherence (MPR < 80%). Similar results were found for Model 2 (median MPR). There was a significant direct relationship between medication concerns (β = −0.13, p < .01) and nonadherence. Therapy-related (β = −0.04, p < .05) and patient-related factors (β = −0.06, p < .05) also had a significant mediating effect on nonadherence through medication concerns. Health care professionals need to address medication concerns and management of adverse effects in older populations to improve adherence and clinical outcomes.

Measuring Rights-Based Practice: Introducing the Human Rights Methods in Social Work Scales

2019 ◽  
Vol 50 (1) ◽  
pp. 222-242 ◽  
Author(s):  
Jane McPherson ◽  
Neil Abell
Keyword(s):  
Human Rights ◽  
Factor Analysis ◽  
Social Work ◽  
Social Workers ◽  
Root Mean Square ◽  
Interdisciplinary Collaboration ◽  
Social Work Practice ◽  
Mean Square ◽  
Convenience Sample ◽  
The Impact

Abstract This article introduces a measurable framework for rights-based social work practice and an accompanying set of instruments, the Human Rights Methods in Social Work (HRMSW) scales: (i) ‘participation’, (ii) ‘non-discrimination’, (iii) ‘strengths perspective’, (iv) ‘micro/macro integration’, (v) ‘capacity-building’, (vi) ‘community and interdisciplinary collaboration’, (vii) ‘activism’ and (viii) ‘accountability’. These scales, designed for use by researchers, educators and practitioners, are the first to measure social workers’ use of rights-based methods. An electronic survey was used to collect data from a convenience sample of 1,014 licensed US social workers, and a confirmatory factor analysis was used to validate the scales’ psychometric properties. A respecified model using eight error covariances fit the data (χ2/df ratio = 2.9; comparative fit index (CFI) = 0.91; tucker lewis index (TLI) = 0.90; root mean square error of approximation (RMSEA) = 0.04; standardized root mean square residual (SRMR) = 0.07). Thus, factor analysis yielded a set of eight related scales—collectively called the HRMSW—each measuring a different human rights practice method that social workers can use to promote human dignity and the rights-based principles of participation, accountability and non-discrimination. Scholars argue that ‘human rights’ are a more appropriate yardstick for measuring the impact of social work intervention rather than our traditional aim of social justice; the HRMSW scales can help us begin to test this proposition.

scholarly journals Assessment of the Accuracy of Recent Empirical and Assimilated Tidal Models for the Great Barrier Reef, Australia, Using Satellite and Coastal Data

2019 ◽  
Vol 11 (10) ◽  
pp. 1211 ◽  
Author(s):  
Fardin Seifi ◽  
Xiaoli Deng ◽  
Ole Baltazar Andersen
Keyword(s):  
Great Barrier Reef ◽  
Sea Level ◽  
Root Mean Square ◽  
Tide Gauge ◽  
Bottom Topography ◽  
Deep Ocean ◽  
Mean Square ◽  
Barrier Reef ◽  
In Situ Data ◽  
The Impact

The latest satellite and in situ data are a fundamental source for tidal model evaluations. In this work, the satellite missions TOPEX/Poseidon, Jason-1, Jason-2 and Sentinel-3A, together with tide gauge data, were used to investigate the performance of recent regional and global tidal models over the Great Barrier Reef, Australia. Ten models, namely, TPXO8, TPXO9, EOT11a, HAMTIDE, FES2012, FES2014, OSUNA, OSU12, GOT 4.10 and DTU10, were considered. The accuracy of eight major tidal constituents (i.e., K1, O1, P1, Q1, M2, S2, N2 and K2) and one shallow water constituent (M4) were assessed based on the analysis of sea-level observations from coastal tide gauges and altimetry data (TOPEX series). The outcome was compared for four different subregions, namely, the coastline, coastal, shelf and deep ocean zones. Sea-level anomaly data from the Sentinel-3A mission were corrected using the tidal heights predicted by each model. The root mean square values of the sea level anomalies were then compared. According to the results, FES2012 compares more favorably to other models with root mean square (RMS) values of 10.9 cm and 7.7 cm over the coastal and shelf zones, respectively. In the deeper sections, the FES2014 model compares favorably at 7.5 cm. In addition, the impact of sudden fluctuations in bottom topography on model performances suggest that a combination of bathymetric variations and proximity to the coast or islands contributes to tidal height prediction accuracies of the models.

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